Watchdog Timer and One-Shot to Insure Safe Operation of a Robotic Manipulator
Original Publication Date: 1987-Sep-01
Included in the Prior Art Database: 2005-Feb-01
This article describes an integrity check circuit arrangement utilizing a watchdog timer and one-shot for use by a robotic system which enhances the safe operation of a robot manipulator by causing motor power to be disabled in the event of processor failures. Robot motors are dependent on the integrity of slave processors for their controlled operation. Accordingly, a means of checking the processors in realtime is required. The circuit arrangement, disclosed herein, provides this integrity check. It can be applied to a robot which utilizes an STD bus with a single master and multiple slave processor cards. Each slave processor controls a single motor of a tool or manipulator joint. The master processor provides the interface between the controller and the user. Both cards are based on the Intel 8088 microprocessor.