Robotoy Technical Details

Robotoy is a Mitsubishi Micro-Robot. It is a RM-101 model and is intended for educational and hobby use only. It does not have the precision nor the robustness required for an industrial robot. It has 6 axes, each of which are driven by a stepper motor. The robot has 5 degrees of freedom; rotation of body, shoulder, elbow and wrist. The 5th degree of freedom is the bending of the wrist.

The robot is controlled by the manipulation of the individual joint angles. In more technical terms, this refers to the "joint space" of the robot. There is no sensory feedback between the robot and the controlling computer. "Soft Limits" are calculated and maintained by the control system to protect the robot. This is far from ideal and presents itself with many problems. For example, if power is lost to the robot, then when the system is restored there is no way of knowing the robot's current position.

The gripper is a simple parallel jaw device that does not have a high gripping force so that only relatively small objects can be picked up. The payload capacity of Robotoy is about 500 grams (or 1 pound, 2 ounces). The range of movement for the robot is as follows;

Movement	Range
Rotation of Body	240 degrees
Rotation of Shoulder	150 degrees (75 forward, 75 backward)
Rotation of Elbow	120 degrees (75 forward, 45 backward)
Bending of Wrist	180 degrees
Rotation of Wrist	360 degrees

The 6 axes are controlled simultaneously. This means that if a complex operation is programmed, all 6 axes will move in a coordinated manner such that all 6 axes will arrive at their programmed destination simultaneously. This is referred to as coordinated motion. The commands are transmitted to the robot using the parallel or printer port interface of the computer.

The vision feedback is based on two, MCAM100 USB webcams. When a movement is commanded by the user, frames are taken at one-second intervals and the a script running on the client will upload new images continuously. Depending upon the speed of your connection and the range of movement requested, several frames may be seen by the user as the robot is in motion. Generally, if you have a slow connection you'll probably only see the final position of the robot.

Go back to Robotoy's homepage.