Helpmate Mobile Robot

HelpMate, a mobile robot, is a Leader robot of a multi-mobile robot team called a Robot Convoy (see Figure 1), under DARPA Mobile Autonomous Robot Software (MARS) Project. The Helpmate mobile robot was donated by Yaskawa Electric of Japan.


Figure 1: The HelpMate Mobile Robot with a Squad Robot on the cart attached

The original hardware of HelpMate consists of a base drive calledLabMate, 18 sonar sensors, and a 386 on-board computer, and Helpmate has been upgraded with the following new features:

  • A 400MHz Pentium II motherboard
  • A 500MHz AMD-K6 motherboard
  • A active LCD monitor with a 2-port switch kit
  • A Lidar sensor for navigation
  • A vision system, stereo cameras and two PCI color-frame grabbers
  • New control software, based on IMA2
  • Connection to the Internet via wireless Ethernet

Hardware

Two motherboards have been added into HelpMate's system. The 400MHz Pentium II motherboard, equipped with 196Mbyte RAM, two PCI color-frame grabbers, and stereo cameras, is responsible for image processing, e.g., object recognition, landmark recognition etc, and Pan-Tilt head control, via two serial ports. The 500MHz AMD-K6 motherboard with 128Mbyte RAM is used for controlling the base drive, sensors, and the navigation system. All sensor data are pre-processing, e.g., noise rejection, hardware error detection, before available to other agents. Both PCs are connected to the Internet via wireless Ethernet. Because of HelpMate's space and payload limitation, the monitor used on-board is a small color-LCD monitor, which is lightweight and less energy consuming. The monitor is connected to both on-board PCs via a 2-port switch kit.


Note that HelpMate used to have a 5DOF rubbertuator-actuated SoftArm installed.

Software

Helpmate is developing under a new software architecture, called Intelligent Machine Architecture, IMA [1], will allow a combination of local autonomy and user direction, enabling Helpmate to navigate hallways and rooms to accomplish tasks. We are also using HelpMate as a test bed for IMA2, a Revised Version ofIMA. HelpMate's control architecture is based on behavior-based [2], Subsumption architecture [3]. Figure 2 shows examples of atomic agents that were built for the HelpMate robot.


Figure 2: Example of atomic agents for the HelpMate robot

Control Architecture & GUI

HelpMate's control architecture is based on Brook's Subsumption architecture. Figure 3 shows example of Subsumption-based control architecture for HelpMate's navigation




Figure 3: Control Architecture for HelpMate's Navigation based on Subsumption Architecture

Under the IMA architecture, HelpMate is designed to make use of user-centered interface as a means of designing Graphical User Interface (GUI) for display and control of mobile robots including their sensors. We accomplish this through a user interface agent called the Commander Agent. Figure 2 illustrates our agent-based HRI (Human-Robot Interface).




Figure 4: An Example of HelpMate's GUI showing a map, image and navigation control

Noteworthy Publications

  1. Thongchai, S., Suksakulchai, S., Wilkes, D., Sarkar, N., "Sonar Behavior-Based Fuzzy Control for a MobileRobot," 2000 IEEE International Conference on Systems, Man & Cybernetics, pp.3532-3537, Nashville, TN, October 8-11,2000.
  2. Suksakulchai, S.,Thongchai, S., Wilkes, D., Kawamura, K., "Mobile Robot Localization using an Electronic Compass for CorridorEnvironment," 2000 IEEE International Conference on Systems, Man & Cybernetics, pp.3354-3359, Nashville, TN, October 8-11,2000.
  3. Jian, P.,S. Srikaew, A., Wilkes, D., Peters II, R., "An Active Vision System for Mobile Robots," 2000 IEEE International Conference on Systems, Man & Cybernetics, pp.1472-1476, Nashville, TN, October 8-11,2000.
References

[1]R.T. Pack, D.M. Wilkes, and K. Kawamura, "A Software Architecture for Integrated Service Robot Development",1997 IEEE Conf. On Systems, Man, and Cybernetics, Orlando, pp. 3774-3779, September, 1997.

[2]Arkin, R.A., Behavior-Based Robotics, MIT Press, Cambridge, MA, 1998.

[3] Brooks,R.A., "A Robust Layered Control System for a Mobile Robot", IEEE Journal of Robotics and Automation, 2:1, pp.14-23, 1986.