Hardware realization of inverse kinematics for robot manipulators

For real-time processing of kinematic information required for intelligent robotic applications, a hardware realization of an inverse kinematics algorithm is a challenging task. This paper adopts an incremental unit computation method to accomplish the inverse kinematics of a three-axis articulated robot. This method starts from defining incremental units in joint and Cartesian spaces, which represent the position resolutions in each space. With this approach, calculation of the inverse Jacobian matrix can be realized through a simple combinational logic gate circuit. Furthermore, the incremental direct kinematics can be solved by using a digital differential analyzer (DDA) integrator. The hardware architecture to implement the algorithm is also described. Applying the hardware implemented by an erasable programmable logic device (EPLD) to the straight-line trajectory of an experimental robot, the authors have obtained an end-effector´s maximum speed of 12.6 m/s