A configurable VLSI chip for DC motor control for compact, low-current robotic systems

Architecture and design parameters for a customizable VLSI chip to control a 34-axis robotic system are presented. The robot, which will be used in throat surgery, includes three small snake-like mechanisms, which places tough design challenges on the controller because of their requirement for precise sensing and control of low motor currents. The chip, in concert with control algorithms executed on a supervisory microprocessor, will deliver the appropriate control voltages to the motor to guide the end-effectors of the robot, while compensating for changes in resistance to motion as the robot interacts with tissue. The chip provides estimates of position, torque and velocity measurements to the microprocessor through a digital interface. Control signals, both generated on-chip and from the microprocessor, are conditioned and presented to the motor driver. The digital interface allows the chip to be configured for different motor specifications and various environmental conditions. Though designed for this particular robot, the chip can be applied to other robots with small DC brush motors