ActivMedia Robotics Pioneer 2 User manual

Pioneer 2
MOBILE ROBOTS
with Pioneer 2 Operating System Servers
OPERATIONS
MANUAL
THE PIONEER 2 MOBILE ROBOT

ii
Copyright © 1999, ActivMEDIA ROBOTICS, LLC
All rights reserved.
Under international copyright laws, this manual or any portion of it
may not be copied – or in any way duplicated – without the
expressed written consent of ActivMEDIA ROBOTICS.
The software on disk and on the Pioneer 2 controller ROM, which accompany the robot
and / or are available for network download by Pioneer Mobile Robot customers,
are solely owned and copyrighted or are products of SRI International
as licensed for distribution by ActivMEDIA ROBOTICS.
Pioneer developers and users are authorized by revocable license to develop and
operate custom software for personal research and educational use only.
Duplication, distribution, reverse-engineering, or commercial
application of the Pioneer software and hardware
without the expressed written consent of
ActivMEDIA ROBOTICS. is explicitly forbidden.
The various names and logos for products used in this manual are often
registered trademarks or trademarks of their respective companies.
Mention of any third-party hardware or software constitutes
neither an endorsement nor a recommendation.
ActivMEDIA ROBOTICS, LLC
44 Concord Street, Peterborough, NH 03458, USA •
www.ActivMedia.com/robots
603-924-9100 • Fax [phone]
Pioneer 2 Mobile Robot – Operations Manual, v4 August, 1999

Pioneer Mobile Robots
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Table of Contents
............................................................................................................................
1. CONGRATULATIONS....................................................................................1
Pioneer Package ....................................................................................................1
Basic Components (all shipments)................................................................................................................1
Optional Components and Attachments (partial list) ..................................................................................1
User-Supplied Components / System Requirements...................................................................................2
Additional Resources.............................................................................................2
Pioneer Software............................................................................................................................................2
Pioneer Newsgroup........................................................................................................................................2
Support............................................................................................................................................................3
2. WHAT IS PIONEER? .....................................................................................4
Client Software......................................................................................................4
The Pioneer Legacy...............................................................................................5
Modes of Operation...............................................................................................6
3. SPECIFICATIONS & CONTROLS..................................................................8
Physical Characteristics .........................................................................................8
Main Components .................................................................................................8
Console and Deck..........................................................................................................................................9
Body..............................................................................................................................................................10
Nose..............................................................................................................................................................10
Accessory Panels..........................................................................................................................................10
Sonar Arrays.................................................................................................................................................10
Motors and Position Encoders..............................................................................10
Sonars................................................................................................................. 10
Batteries and Power............................................................................................. 11
Electronics ..........................................................................................................12
Power/Motor Board.....................................................................................................................................12
Microcontroller ............................................................................................................................................12
Sonar Boards................................................................................................................................................13
Controls, Ports, and Indicators .............................................................................13
Main Power, Fuse, and Indicator................................................................................................................13
Recharge/Power Port...................................................................................................................................13
Liquid-Crystal Display................................................................................................................................13
Contrast.........................................................................................................................................................13
.......................................................................................................................................................................14
SERIAL........................................................................................................................................................15
RADIO..........................................................................................................................................................15
FLASH..........................................................................................................................................................15
Safety Watchdogs and Configuration................................................................... 15
4. QUICK START.............................................................................................16
Preparative Assembly ..........................................................................................16
Saphira Client Installation...........................................................................................................................16
Saphira Client Start-Up........................................................................................ 17
Pioneer Cold Start-Up.......................................................................................... 17
RADIO ON...................................................................................................................................................17
Starting Saphira Client/Pioneer Server Communications ......................................17
A Successful Connection..................................................................................... 18
Operating the Saphira Demo Client...................................................................... 18
Disconnecting Serial Communications (intentionally or unintentionally)...............20
Quickstart Troubleshooting..................................................................................20
5. SELF-TESTS ...............................................................................................22
Engaging Self-Tests.............................................................................................22
Motors Test.........................................................................................................22
Sonar Test........................................................................................................... 22

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DIGIN Test..........................................................................................................23
DIGOUT Test......................................................................................................23
ANALOG Tests ...................................................................................................23
Bumps .................................................................................................................24
User PWMs..........................................................................................................24
P2 Gripper ...........................................................................................................24
6. PIONEER 2 OPERATING SYSTEM............................................................. 25
Communication Packet Protocol...........................................................................25
Packet Data Types.......................................................................................................................................26
Packet Checksum.........................................................................................................................................26
Packet Errors................................................................................................................................................26
Server Information Packets...................................................................................27
Client Commands.................................................................................................28
Client Command Argument Types.............................................................................................................29
Saphira Client Command Support..............................................................................................................30
Programming P2OS .............................................................................................30
Synchronization—SYNC............................................................................................................................30
Autoconfiguration........................................................................................................................................31
Opening the Servers—OPEN ......................................................................................................................31
Keeping the Beat—PULSE.........................................................................................................................31
Closing the Connection—CLOSE...............................................................................................................31
Movement Commands..........................................................................................31
Pioneer in Motion.................................................................................................32
Position Integration......................................................................................................................................32
Sonars..................................................................................................................33
Input / Output (I/O)..............................................................................................33
Digin, Timer, and ADSEL..........................................................................................................................33
DIGOUT and PSUPOS...............................................................................................................................34
BUMPSTALL......................................................................................................34
Extended Packets .................................................................................................35
Packet Processing........................................................................................................................................35
Configuration Packets .................................................................................................................................35
Encoder Packets...........................................................................................................................................35
AUX Serial Packets.....................................................................................................................................36
Standalone Mode..................................................................................................37
7. UPDATING & RECONFIGURING P2OS...................................................... 38
Where to Get P2OS Software ...............................................................................38
Installing the P2OS Utilities .................................................................................38
Updating P2OS ....................................................................................................38
Step 1. Serial Connection from Computer to Pioneer...............................................................................38
Step 2: Enable FLASH................................................................................................................................38
Step 3: Put Pioneer into Boot Mode...........................................................................................................38
Step 4: Run p2osdl.......................................................................................................................................39
Download Troubleshooting.........................................................................................................................39
Configuring P2OS Operating Parameters..............................................................39
Steps 1–3: Preparing Pioneer 2 for Configuration.....................................................................................39
Step 4: Run p2oscf.......................................................................................................................................39
Step 5: Changing the Configuration Parameters........................................................................................39
Editing P2OS Parameters............................................................................................................................40
Saving and Restoring...................................................................................................................................42
Calibration Tools - revcountcal and compasscal....................................................42
8. MAINTENANCE & REPAIR ......................................................................... 44
Drive Lubrication.................................................................................................44
Pioneer Batteries..................................................................................................44
Changing Batteries (DX and AT)...............................................................................................................44
Hot-Swapping the Batteries (DX and AT).................................................................................................44
Charging the Battery....................................................................................................................................44
Alternative Battery Chargers ......................................................................................................................44
Factory Repairs....................................................................................................45
APPENDIX A................................................................................................... 46
Console Serial Port...............................................................................................46
Internal Serial Connectors ....................................................................................47

Pioneer Mobile Robots
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User I/O Expansion Port......................................................................................47
The General I/O Bus............................................................................................48
APPENDIX B ...................................................................................................50
User Power Connections...................................................................................... 50
Onboard Computer Option................................................................................... 51
Power Switch (J7) and Delayed Shutdown Logic ....................................................................................51
Power-State Logic........................................................................................................................................51
Computer Power ..........................................................................................................................................51
APPENDIX C...................................................................................................52
APPENDIX D...................................................................................................54
INDEX..............................................................................................................56
WARRANTY & LIABILITIES.............................................................................58

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Pioneer Mobile Robots
1
Congratulations
on your purchase of this Pioneer 2 Mobile Robot, and welcome to the rapidly growing community
of researchers, developers, and enthusiasts of Pioneer Mobile Robots .
This Pioneer 2 Operation Manual provides both the general and technical details you need to operate
your Pioneer 2 Mobile Robot and to begin developing your own robotics hardware and software projects.
We encourage you to also use the companion resources that are packaged with your Pioneer Mobile Robot:
ŸSaphira, Ayllu, Pioneer Application Interface and P-LOGO software and manuals
ŸPersonal account for the Internet server: http://robots.activmedia.com
ŸPioneer-user newsgroups
Pioneer Package
Our experienced robotics-manufacturing staff put your Pioneer 2 Mobile Robot and accessories through
a “burn in” period and carefully tested them before shipping the robot to you. Our care extends beyond.
In addition to the companion resources listed above, we warranty the robot and our manufactured
accessories against mechanical, electronic, and labor defects for one year. Third-party accessories are
warranted by their manufacturers, typically for 90 days.
All of these precautions ensure that you have many years to enjoy your new Pioneer 2 Mobile Robot.
Even though we’ve made every effort to make your Pioneer package complete, please check the
components again after you unpack them from the shipping crate.
Basic Components (all shipments)
ŸOne fully assembled Pioneer 2 Mobile Robot
Ÿ3.5-inch floppy disks containing licensed copies of Pioneer 2 software
and documentation for Windows 95/NT platform
ŸHex wrenches and assorted replacement screws
ŸReplacement fuse
ŸSet of manuals
ŸRegistration and Account Sheet
Optional Components and Attachments (partial list)
ŸBattery charger (some contain power receptacle and 220VAC adapters)
ŸOnboard EBX computer with PC104+ bus, hard-drive and other accessories
ŸRadio Ethernet and/or Modems
ŸOne mounted inside Pioneer 2
ŸCompanion radio for LAN or basestation connection
ŸSupplementary and replacement batteries
Ÿ3-Battery Simultaneous Charge Station (110/220 VAC)
ŸGripper
ŸFast-Track Color Vision System
ŸRange-Finding StereoCam System
ŸPan-Tilt-Zoom Surveillance System
ŸCustom Vision System

Congratulations
2
ŸRange-finding Laser
ŸGPS System
ŸCompass
ŸBumper Ring
ŸSerial cables for external connections
User-Supplied Components / System Requirements
ŸClient computer: 486-class or later PC with Microsoft Windows 95-98/NT,
FreeBSD, or Linux operating system; Power-PC Macintosh with System 7.5
or later; or any UNIX workstation
ŸOne RS-232-compatible serial port
ŸFour megabytes of available hard-disk storage
Additional Resources
Every new Pioneer customer gets three additional and valuable resources:
1. A private account on our Internet server for downloading Pioneer software, updates, and manuals
2. Access to the private pioneer-users newsgroup
3. Direct access to the Pioneer technical support team
Pioneer Software
We maintain a 24-hour, seven-day per week Web server where customers can obtain Pioneer software
and support materials:
http://robots.activmedia.com
Some areas of the Pioneer website are restricted to licensed customers. To gain access, enter the username
and password written on the Pioneer Registration & Account Sheet that accompanied your robot
and this manual.
Pioneer Newsgroup
We maintain an E-mail-based newsgroup through which Pioneer owners share ideas, software, and
questions about the robot. To sign up, send an E-mail message to our automated newsgroup server:
To: [email protected]
From: <your return e-mail address goes here>
Subject: <choose one command:>
help (returns instructions)
lists (returns list of newsgroups)
subscribe
unsubscribe
Our SmartList-based listserver will respond automatically. After you subscribe, send your E-mail
comments, suggestions, and questions intended for the worldwide community of Pioneer users:
To: [email protected]
From: <your return e-mail address goes here>
Subject: <something of interest to members of pioneer-users>
Access to the Pioneer-users Newslist is limited to subscribers, so your address is safe from spam.
However, the list currently is unmoderated, so please confine your comments and inquiries to issues
concerning the operation and programming of Pioneer.

Pioneer Mobile Robots
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Support
Have a problem? Can’t find the answer in this or any of the accompanying manuals? Or, do you know
a way that we might improve Pioneer? Share your thoughts and questions directly with us:
[email protected]
Please include your robot's serial number (look for it beside the Main Power switch) -- we often need to
understand your robot's configuration to best answer your question.
Your message goes directly to the Pioneer technical support team. There a staff member will help you
or point you to a place where you can find help.
Because this is a support option, not a general-interest newsgroup like pioneer-users, we reserve the
option to reply only to questions about problems with Pioneer.
(See Chapter 8, Maintenance & Repair, for details.)

4
What Is Pioneer?
Pioneer is a family of mobile robots, both two-wheel and four-wheel-drive. They are all small, intelligent
robots, whose architecture was originally developed by Kurt Konolige, Ph.D., of SRI International.
These are truly off-the-shelf, “plug and play” robots, containing all of the basic components for sensing and
navigation in a real-world environment, including battery power, drive motors and wheels, position / speed
encoders, and integrated sensors and accessories. They are all managed via an onboard microcontroller and
mobile-robot server software.
Your Pioneer 2 also has a variety of expansion power and I/O ports for optional, custom attachments.
They include an addressable I/O bus for up to 16 devices, two RS-232 serial ports, eight digital I/O ports,
five A/D ports, PSU controllers and more — all accessible through a common application interface to the
robot server software, P2OS.
With the onboard computer option, Pioneer 2 has four additional RS-232 ports, a PCI bus and space for up
to five PC104+ accessory cards. With Ethernet-ready onboard autonomy, the Pioneer becomes a plug-and-
play agent for multi-intelligence work.
Figure 2-1. The Basic Components of a Pioneer 2 DX
Client Software
Pioneer 2 comes with a variety of mobile robotics development software. Currently available Pioneer client
software for the computing platform of your choice (UNIX, Linux, Macintosh, Win32) includes:
•The Saphira client development suite with Colbert
•Ayllu subsumption-like system, with multi-agent extensions
•Pioneer simulator
•Pioneer LOGO (P-LOGO)
•Pioneer Application Interface (PAI)
The Windows 95/98/NT versions of the available software with manuals arrive with your Pioneer 2. Other
versions and all updates for supported computing platforms are available to password-registered customers
for download from our software website (see Congratulations, Chapter 1):

Pioneer Mobile Robots
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http://robots.activmedia.com
Currently supported client operating systems include most UNIX, Apple Macintosh, SunOS and Solaris
from Sun Microsystems, Linux, Silicon Graphics' IRIX, and Microsoft’s Win32 (32-bit) Windows.
Saphira comes with a command-line interactive language, Colbert, and a demonstration program that
allows manual (keyboard or joystick) and automatic drive control of Pioneer. The program also lets you
enable several built-in robotic behaviors, including collision avoidance, features recognition, and self-
navigation. For details, see Quick Start, Chapter 4.
Pioneer Application Interface (PAI) is a C-language development suite that works with Saphira. It lets
software developers gain closer control of the low-level details of Pioneer server. See the PAI Manual
for details.
Pioneer LOGO is a version of UCB-LOGO from the University of California-Berkeley, which we’ve
extended to include Pioneer commands. It provides direct, interactive control of the robot through
a familiar programming language. See the P-LOGO Manual for details.
Ayllu is a tool for development of behavior-based control systems for mobile robots. It extends
subsumption-style message passing to the multi-robot domain, provides for a wide variety of behavior-
arbitration techniques, and allows a great deal of run-time system flexibility. This includes a dynamic
reconfiguration of behavior structure and redistribution of tasks across a group of robots as determined
by either task constraints or changing availability of resources. See the Ayllu Programmer’s Manual for
details.
An important benefit of Pioneer’s client/server architecture is that different robot servers can be run using
the same high-level client. For example, the included Pioneer simulator runs on the host machine and acts
just like the robot, so that developers may conveniently perfect their application software, then run it
without modification on the robot. Several clients also may share responsibility for controlling a single
mobile server, which permits experimentation in distributed communication, planning, and control.
Figure 2-2. In client/server mode, Pioneer 2 requires a host computer connection.
The Pioneer Legacy
Pioneer 1 was the original design. It introduced a 68HC11-based microcontroller and the Pioneer Server
Operating System (PSOS) software.
Intended mostly for indoor use on hard, flat surfaces, the Pioneer 1 has solid rubber tires and a two-wheel
differential, reversible drive system with a rear caster for balance. The Pioneer 1 came standard with seven
sonar range finders (two side-facing and five forward-facing) and integrated wheel encoders.
Software-wise, the Pioneer 1 initially served as a platform for SRI International's AI/fuzzy logic-based
Saphira robotics applications development. But it wasn't long before it's open architecture became the
popular platform for the development of a variety of alternative robotics software environments.
Many developers created software that interfaced directly with PSOS. Others extended the capabilities of
Saphira (PAI and P-LOGO are two good examples), while others have implemented alternative robotics-
control architectures, such as the subsumption-like Ayllu.

6
Functionally and programmatically identical to the Pioneer 1, the four-wheel drive, skid-steering Pioneer
AT was introduced for operation in uneven indoor and outdoor environments, including loose, rough
terrain. Each side of the Pioneer AT is electronically and physically linked for evenly applied translational
and rotational power and speeds.
Except for the drive system, there are virtually no operational differences between the Pioneer AT and the
Pioneer 1: The integrated sonar arrays and microcontrollers are the same. The accessories available for the
Pioneer 1 also work with the Pioneer AT. Further, applications developed for the Pioneer 1 work with little
or no porting to the Pioneer AT, and vice versa.
The newest generation of Pioneer Mobile Robots – including the Pioneer 2 CE, DX, and AT models –
improves upon the Pioneer 1 legacy while retaining its many important features. Indeed in most respects,
particularly with applications software, Pioneer 2 works identically with Pioneer 1 models.
Sporting a more holonomic body, larger wheels and stronger motors for better indoor performance, the
Pioneer 2-DX and CE models, like Pioneer 1, are two-wheel, differential-drive mobile robots. (The least
expensive CE model comes with fewer options and expansion capabilities than the 2-DX.)
The four-wheel drive Pioneer 2-AT has independent motor-drivers, as well as a stall-detection systems.
Unlike its predecessor, the Pioneer 2-AT comes with inflatable tires and metal wheels for much more
robust operation in rough terrain, as well as the ability to carry nearly 45 kilograms (90 lbs) of payload and
climb a 60-percent grade.
All Pioneer 2 models use a high-performance 20 MHz Siemens 88C166-based microcontroller, with
independent motor/power and sonar-controller boards for a versatile operating environment. The controller
has two RS232-standard communications ports and an expansion bus to support the many accessories
available for Pioneer, as well as your own custom attachments. And the Pioneer 2 comes with high-
precision (9,850 ticks-per-revolution) wheel-motor encoders for finer odometry, and translational and
rotational speed controls. The Pioneer 2 also supports a full complement of sixteen sonars (eight front and
eight rear) for nearly seamless object detection.
Software-wise, the Pioneer 2 is upwardly compatible with Pioneer 1: The Pioneer 2 Operating System
(P2OS) software extends – but does not replace – the original PSOS. This means that even programs that
interface at the lowest communication levels will work with both Pioneer 1 and with Pioneer 2 platforms.
This also means that the higher level clients, such as Saphira, PAI, Ayllu, P-LOGO, and others, will work
with P2OS and the host Pioneer 2 platform just as they had worked with Pioneer 1. Of course, you will
have to extend your client software, as we have done with Saphira, Ayllu and others, in order to take full
advantage of P2OS.
To the relief of those who have invested years in developing software for Pioneer 1, Pioneer 2 truly does
combine the best of the new mobile robot technologies with the tried-and-true architecture of the original
Pioneers.
Modes of Operation
You may operate Pioneer 2 in one of three modes:
•Self-test
•Stand-alone
•Server mode
The Pioneer 2 controller comes with 32K flash-programmable, read-only memory (flash-ROM) as part
of its Siemens 88C166 microprocessor, and an additional 32K of dynamic RAM: 64K total memory space
for your stand-alone robotics programs.
But we don't recommend that you start learning C166 programming. Rather, the robot comes to you
installed with the latest P2OS robotics server software.

Pioneer Mobile Robots
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In conjunction with client software, such as Saphira, Ayllu, or PAI running on the onboard PC or a user-
supplied computer, P2OS lets you take advantage of modern client /server and robot-control technologies
to perform advanced robot tasks. (See Chapter 6, Pioneer 2 Operating System, for details.)
Most users run Pioneer in this server mode, because it gives them quick, easy access to the robotics
functionality while working in high-level software on a familiar host computer.
For experiments in microcontroller-level operation of robotics functions, you may reprogram the onboard
flash-ROM and RAM for direct and stand-alone operation of Pioneer 2. We supply the means to download,
but not the microcontroller's programming software, for you to work in stand-alone mode.
In fact, the download utilities we provide for you to reprogram the 88C166-based controller's flash-ROM
and RAM also are used to update and upgrade your P2OS. We typically provide the upgrades free for
download from our website, so be sure to sign up for the pioneer-users newslist. That's where we notify
our customers of the upgrades, as well as where we provide access to Pioneer users worldwide.
Finally, we provide some test programs that exercise Pioneer 2 microcontroller hardware and software.
We examine that mode in some detail in Chapter 5, Self-Tests.

Specifications and Controls
8
Specifications & Controls
Pioneer robots may be smaller than most, but they pack an impressive array of intelligent mobile robot
capabilities that rival bigger and more expensive machines. For example, the Pioneer 2DX and CE’s
modest size lends itself to navigation in tight quarters or cluttered spaces, such as classrooms, laboratories
and small offices (see (Figure 3-1).
At the same time, the powerful Pioneer server, with its Saphira software client, is fully capable of mapping
its environment, finding its way home and performing other sophisticated path planning.
Physical Characteristics
For a complete comparison of Pioneer 2’s physical and operational specifications, see Appendix D.
Figure 3-1. The Pioneer 2 DX/CE physical dimensions and swing radius
Weighing only 9 Kg (20 pounds with one battery), the basic Pioneer 2 Mobile Robot is lightweight,
but its strong aluminum body materials, solid construction, and strut-reinforced wheels make it virtually
indestructible.
These characteristics also permit Pioneer 2 to carry extraordinary payloads: The DX can carry up to 23 Kg
(50 lbs.) additional weight; the Pioneer 2 AT can carry over 40 Kg (90 lbs.) more! Yet the Pioneer 2 is
light-weight enough that it is also as easy to transport as a suitcase – a task made even easier by the Pioneer
2's built-in handle. And because Pioneer's main components are assembled with Allen hex screws (metric
sizes; tools included with robot), you have quick access to interior components and can attach accessories
with a minimum of effort.
Main Components
All Pioneer 2's are composed of six main sections:
•Console
•Deck
•Body

Pioneer Mobile Robots
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•Nose
•Sonar Arrays
•Accessory Panels
Console and Deck
The Pioneer 2 Console and Deck are actually one piece – the top plate of the robot. The Deck is simply
the flat surface for mounting projects and accessories, such as the PTZ Camera or a laser range finder.
Feed-through slots behind the wheels let you conveniently route cables to the accessory panels on each side
of the DX/CE or trough an access panel on top of the Pioneer 2 AT. A removable plug in the middle of the
Deck gives you convenient access to the interior of the robot.
In general, you should try to center the robot's load over the drive wheels. If you must add a heavy
accessory to the edge of a Pioneer 2-DX or 2-CE deck, counterbalance the weight with a heavy object
on the opposite end of the deck. A full complement of batteries helps balance the robot, too.
Figure 3-2. Pioneer 2’s Console and Deck

Specifications and Controls
10
Every Pioneer 2 has a Console that consists of a liquid-crystal display (LCD), MOTORS and RESET
control buttons and indicators, and an RS232-compatible serial port at the 9-pin DSUB connector on the
front and top of the Deck.
Attached directly underneath the Console is the Pioneer 2 microcontroller. (Operational details are
provided in the next chapter, Quick Start.)
Body
Pioneer 2’s sturdy, but lightweight aluminum Body houses the robot's batteries, drive motors, electronics,
and other standard components, including the forward and rear sonar arrays. The Body also has sufficient
room, with power and signal connectors, to support a variety of robotics accessories inside, including the
Fast-Track Color Vision System, radio modems and radio Ethernet, onboard computer, and many more.
On the DX and AT models, the Pioneer 2 has a hinged rear door for easy access to the batteries.
Accordingly, you may quickly hot-swap and replace any of up to three batteries.
Also at the rear of the DX and CE Body is a convenient carry handle for easy transport of the robot.
Nose
The Nose of Pioneer 2 is empty, except when equipped with an onboard PC. The Nose is readily
removable: Simply remove one screw from under the front sonar array, and a second screw from the
bottom of the Pioneer 2, then slide the Nose away. This provides a quick and easy way to get at the PC104+
stack of accessory boards of the onboard PC, as well as to the sonar gain adjustment for the front sonar
array (see Sonar Gain below). The Nose also is an ideal place for you to attach your own custom
accessories and sensors.
Accessory Panels
The Pioneer 2 DX comes with a removeable panel on each side of the robot on which you can install
accessory connnectors and controls. A special sidepanel comes with the onboard PC option, for example,
which gives users monitor, keyboard, mouse (serial port), and 10base-T Ethernet access, as well as the
means to reset and power the computer.
The AT comes with a single accessory panel in the Deck. Fastened down with finger-tight screws, the AT
accessory panel is accessible through its hinged door.
Sonar Arrays
Pioneer 2 supports up to two sonar range-finding arrays. One array, affixed under the front of the Deck and
atop the Nose, provides forward- and side-range sensing. The other, an optional sonar array is attached just
beneath the rear Deck and provides rearward, as well as side sensing. All arrays contain eight sonars, for a
total of 16 sonars around the robot.
Motors and Position Encoders
Pioneer 2’s drive system uses high-speed, high-torque, reversible-DC motors. Each front drive motor
includes a high-resolution optical quadrature shaft encoder that provides 9,850 ticks per wheel revolution
(19 ticks per millimeter) for precise position and speed sensing and advanced dead-reckoning.
Sonars
Pioneer 2 AT and DX supports both front and rear sonar arrays (CE front only), each with eight transducers
that provide object detection and range information for features recognition, as well as navigation around
obstacles. The sonar positions are fixed in both arrays: one on each side, and six facing outward at 20-
degree intervals providing more than 180 degrees of nearly seamless sensing, and all-around sensing when
using both forward and rear arrays.

Pioneer Mobile Robots
11
Figure 3-3. Pioneer 2 sonar array
The sonar firing rate is 25 Hz (40 milliseconds per sonar per array) and sensitivity ranges from 10 cm (6
inches) to more than five meters (16 feet). (Objects closer than 10 cm are not detected.) You may control
the sonar’s firing pattern through software; the default is left-to-right in sequence for the forward array and
right-to-left on the rear. One sonar from each array "ping" simultaneously.
Both the forward and rear sonar sensor arrays are preset at the factory. However, you may adjust their
general sensitivity and range to accommodate differing Pioneer 2 operating environments.
The sonar gain control is on the underside of the sonar driver board, which is attached to the floor of each
sonar module. Remove the Nose to access the front sonar module. Unlatch and open Pioneer 2's back door
to access the rear sonar module.
From the underside, locate a hole near the front of the sonar module through which you can see the
cap of the sonar-gain adjustment potentiometer. Using a flat-blade screwdriver, turn the gain control
counterclockwise to make the sonar less sensitive to external noise and false echoes.
Low sonar-gain settings reduce the robots’ ability to see small objects; under some circumstances, that
is desirable. For instance, attenuate the sonar if you are operating in a noisy environment or on uneven
or highly reflective flooring – a heavy shag carpet, for example. If the sonars are too sensitive, they will
“see” the carpet immediately ahead of the robot as an obstacle.
Increase the sensitivity of the sonar array by turning the gain-adjustment screw clockwise, making the
sonar more likely to see small objects or objects at a greater distance. For instance, increase the sonar
gain if you are operating in a relatively quiet and open environment with a smooth floor surface.
Batteries and Power
The Pioneer 2 CE has a single, twelve-volt, direct-current, seven ampere-hour (84 watt-hour) sealed
lead/acid battery which supplies ample power for its drives, electronics, and accessories. Typical
intermittent operation of the motors gives six or more hours of Pioneer 2-CE use.
The Pioneer 2 DX and AT models may contain up to three, hot-swappable, seven ampere-hour, 12 VDC
sealed lead/acid batteries (total of 252 watt-hours), accessible though a hinged and latched back door.

Specifications and Controls
12
Similar to the CE model, the battery life of the Pioneer 2 DX and AT, of course, depends on the
configuration of accessories and motor activity. Pioneer 2-AT charge life typically ranges from four
to eight hours. Pioneer 2-DX can run for more than a day.
If you don’t use the motors, Pioneer 2’s native electronics will run for several days on a single battery
charge.
Balance the batteries in your Pioneer 2.
IMPORTANT: Batteries have a significant impact on the balance and operation of your robot. For the
Pioneer 2-DX and 2-AT, under most conditions, we recommend operating with three batteries. Otherwise,
a single battery should be mounted in the center, or two batteries inserted on each side of the battery
container.
Typical recharge time using the recommended accessory recharger varies according to the battery’s
discharge state; it is roughly equal to three hours per volt. The optional Charge Cube allows simultaneous
recharge of three swappable batteries outside the robot.
With the optional high-speed Charger, recharge time is greatly reduced, but caare must be taken not to
overcharge and thereby damage batteries.
Electronics
The Pioneer 2’s standard electronics reside on three main boards: The microcontroller is mounted under the
Console Deck; a power / motor controller board is mounted to the battery box inside the robot; and a sonar
controller (one for each array) is mounted in the base of the sonar array.
A Main Power switch at the back of the robot controls power for the entire system. Processor control
switches and indicators fit through the Deck Console.
Power/Motor Board
Inside the robot, mounted to the battery box, is the Pioneer 2 Motor-Power board. It supplies both the
twelve and five VDC power requirements of Pioneer 2's standard systems. Additionally, it has user-
accessible five and 12 VDC connectors, which supply 1–2.5 amperes of power for accessories, depending
on configuration. The Motor-Power board also contains the motor-driver electronics, as controlled by the
microcontroller.
The standard Motor-Power board has a 12-pin user-power connector that supports four sets of five- and
12 VDC power ports (total one ampere) for custom accessories. An optional computer-power section to
the board supplies up to seven amperes at five VDC power for an onboard PC. The power board includes
special low-power and power-down circuit that lets you gently shut down the computer without direct
connection through a keyboard or monitor. (See Appendix B in this manual and the Computer Tech Notes
pamphlet that accompany the Pioneer 2 for details.)
Microcontroller
Pioneer 2's microcontroller uses a 20 MHz Siemens 88C166 microprocessor with integrated 32K flash-
ROM. The microcontroller also has 32K of dynamic RAM, two RS232-compatible serial ports, several
digital and analog-to-digital, and PSU I/O user-accessible ports, and an eight-bit expansion bus. See
Appendix A for port details.)
All the I/O ports, except those used for the motors, encoders, and sonar, are available to the user for Pioneer
2 accessory hardware, which you may control through the P2OS. Port connector pinouts and electronic
details appear in the Appendices.

Pioneer Mobile Robots
13
Sonar Boards
Associated with each sonar array – forward and rear – is a sonar multiplexer / firing board. Wire leads
to the individual sonar plug into a 16-pin connector on the board. A 10-conductor signal cable connects
the sonar board with the microcontroller.
Controls, Ports, and Indicators
Main Power, Fuse, and Indicator
A single slide-switch on the rear left panel of the Pioneer 2 DX, AT and CE models controls power to the
entire robot and all its integrated accessories. Up is ON; down is OFF. A red LED on the Console indicates
Main Power.
Inside, on the top right side of the battery box (accessible through the hinged back door of the Pioneer 2
DX and AT) is the Main Power Fuse. It is an automotive-type (spade terminals) 15A (DX, CE) or 30A
(AT) fuse designed for tool-less replacement. To the left of the fuse, on the same board, is the main power
relay, which isolates the high-ampere draw of the robot system from the Main Power Switch.
Recharge/Power Port
Below the Main Power Switch is the battery Recharger port. It provides 12 VDC power to the robot's
electronics, motors, and accessories, even without batteries. Use the recommended accessory power
charger or equivalent.
You should maintain Pioneer 2’s batteries in a charged state above 11 VDC, as indicated on the robot’s
LCD. We recommend recharging the battery when it falls below 11 VDC, even though the robot may
continue to operate below 10 VDC. The microcontroller will sound a warning when the battery voltage
falls below that set level (see Chapter 7, Updating and Reconfiguring P2OS), and the optional computer
power circuitry will automatically shut down the onboard PC. Discharging the batteries to below 10 VDC
damages them.
Disengage the motors when recharging the robot.
You may continue to operate Pioneer while charging its batteries, although that will lengthen the recharge
time.
If you have only one battery onboard, plug Pioneer into the charger to “hot-swap” the exhausted battery for
a fresh one. To hot-swap two or three batteries, exchange each exhausted battery one-at-a-time for a fresh
one, leaving at least one battery in place to supply power to the robot.
The Pioneer 2 chargers also may be used with the Pioneer 2 Charge Cube accessory.
Liquid-Crystal Display
When powered on, information about the robot's state and connections appears on a 16-character by two-
line liquid-crystal display (LCD) on the left side of Pioneer 2’s Console.
When under control of the P2OS server, for example, the display shows the state of communication with
the client computer, along with the battery voltage and a blinking "heartbeat" asterisk (*) as the last six
characters in the second line of text.
Contrast
A small, contrast-adjustment potentiometer for the LCD is inset next to the display. Make sure the Main
Power switch is on and the battery is well charged. Then, using a small, flat-blade screwdriver, turn the
adjustment screw to darken or lighten the screen so that the characters are clearly visible under your
lighting conditions.

Specifications and Controls
14
Figure 3-3. Pioneer 2 Console
RESET and MOTORS
The RESET (red) and MOTORS (white) push-button switches on the Pioneer 2 Console affect the
microcontroller’s logic and motor driver systems. Both are under software control.
When pressed alone, RESET puts the microcontroller into its start-up state, disrupting any running program
or client connection. It also disables the drive motors – just as if you cycle Main Power. But, unlike a cold-
power restart, RESET preserves the contents of the Pioneer 2 microcontroller's RAM, so any user programs
downloaded in stand-alone mode get restarted.
The MOTORS pushbutton is NOT a power switch – it does not directly control
power to the motors. P2OS does and your stand-alone software must.
The MOTORS button and its associated green LED are under software control. Normally, Pioneer 2's
motors are disabled when not connected to a client, or when not running the self-test or a stand-alone
program on the controller. When running P2OS and connected with a client, the motors remain disabled
(LED flashes) until you press and release the MOTORS button.
The green LED should light continuously when the motors are enabled and blink on / off when disengaged.
Pressing and releasing the white MOTORS button enables / disables the motors when connected with a
P2OS client.