Click on a thumbnail sketch to see the full size picture.
The wood structure near the middle of the picture is the Johnny Walker prototype. This is a one-joint testbed for getting the motor control software and hardware working. The controller is on the left, connected via ribbon cable. The controller is based on a 68HC11 microprocessor. This drives 3 L298N H-bridges running at 18V and senses the voltage at the three motors. In addition the 68HC11 monitors the value of three potentiometers to read the joint angle. Of course with this proto there is only one motor and one potentiometer. Johnny Walker. When Johnny is complete he will be a six legged autonomous robot. Currently he only has one leg so he walks with the aid of a wheelchair. But the leg has three motors as shown here. It requires one 68HC11 controller board per leg. Molly Monster. Molly is a radio controlled water critter so she isn't strictly speaking a robot. But she is a testbed for some of the technology used in the robot work above. In particular I developed the 68HC11 control software for her motor control. She runs at 48V with a 1/5 HP motor, making her fairly fast and almost silent. Her H-bridge is my own custom design using powerMOS. I wasn't planning to build my own H-bridge, but at the time I was unable to find a comercial unit that could drive enough power to control Molly.