ActivMedia Robotics

Chapter 6 Pioneer 2 Operating System

All ActivMedia robots use a client-server

mobile robot-control architecture developed by Dr. Kurt Konolige and others at SRI International. In the model, the robot’s controller servers—the Pioneer 2 Operating System (P2OS)—work to manage all the low-level details of the mobile robot’s systems. These include operating the motors, firing the sonar, collecting sonar and wheel encoder data, and so onall on command from and reporting to a separate client application, such as ARIA or Saphira.

With this client/server architecture, robotics applications developers do not need to know many details about a particular robot server, because the client insulates them from this lowest level of control. Some of you, however, may want to write your own robotics control and reactive planning programs, or just would like to have a closer programming relationship with your robot. This chapter explains how to communicate with and control your ActivMedia robot via the P2OS client-server interface. The same P2OS functions and commands are supported in the various client-programming environments that accompany your robot or are available for separate license.

Figure 19. ActivMedia Robotics client-

server control architecture

Experienced Pioneer users can be assured that P2OS is upwardly compatible with PSOS, implementing all the same commands and information packets. P2OS, of course, extends the servers to add new functionality, improve performance, and provide additional information about the robot's state and sensing. Hence, P2OS-specific programs may not operate on original Pioneers.

Communication Packet Protocol

Table 2. Main elements of PSOS/P2OS communication packet protocol

Component

Bytes

Value

Description

Header

2

0xFA, 0xFB

Packet header; same for client and server

Byte Count

1

N + 2

Number of subsequent data bytes, including

 

 

 

the Checksum word, but not the Byte Count.

 

 

 

Maximum 200 bytes.

Data

N

command

Client command or server information

 

 

or SIP

packet (SIP)

Checksum

2

computed

Packet integrity checksum

P2OS communicates with a client application using a special packet protocol for both command packets from client to server and server information packets (SIPs) from the

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Pioneer 2 / PeopleBot manual Pioneer 2 Operating System, Communication Packet Protocol
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2 / PeopleBot specifications

Pioneer 2, also known as PeopleBot, is an advanced mobile robot platform heralded for its versatile design and robust capabilities. Developed by the renowned robotics company Adept Technology, Pioneer 2 has become a staple in the field of mobile robotics, widely utilized for research, education, and practical applications in various industries.

One of the standout features of Pioneer 2 is its exceptional mobility. The robot is equipped with differential steering, allowing it to navigate complex environments with precision. Its compact and sturdy chassis enables it to traverse a variety of terrains, making it suitable for indoor and outdoor exploration. This mobility is further enhanced by an adaptable wheel configuration, allowing for smooth movement even over obstacles.

In terms of technologies, Pioneer 2 is outfitted with an array of sensors that facilitate autonomous navigation and obstacle avoidance. These sensors include laser range finders, infrared sensors, and bumpers, which work in tandem to map the surrounding environment and detect potential hazards. This capability is critical for applications in areas such as warehouse automation or reconnaissance tasks, where safe navigation is paramount.

Pioneer 2 also supports extensive software frameworks, notably the Robot Operating System (ROS). This compatibility allows researchers and developers to leverage a vast library of tools and algorithms, expediting the process of programming and deploying robotic applications. Additionally, the platform can be integrated with various payloads, such as cameras or grippers, expanding its functionality further.

Another significant characteristic of Pioneer 2 is its user-friendly design. The robot comes with an easy-to-use programming interface that empowers users with varying levels of expertise to engage with the technology. Educational institutions often employ Pioneer 2 in robotics courses to provide students with hands-on experience in programming and operating robotic systems.

Powering Pioneer 2 is a rechargeable battery system that ensures extended operation times. This feature is particularly advantageous for fieldwork applications where connectivity to a power source may not be readily available. Importantly, the robot’s modular design facilitates maintenance and upgrades, allowing users to keep their systems current with advances in technology.

Overall, Pioneer 2 (PeopleBot) exemplifies innovation in mobile robotics with its outstanding mobility, advanced sensing technologies, compatibility with leading software frameworks, and a design focused on ease of use and adaptability. It continues to be a preferred choice for researchers, educators, and professionals in the rapidly evolving landscape of robotics.
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