Abstract: Workpoint torque control is employed in an electron multiaxis robot controller. Robot axis torque is determined from axis motor current feedback. Axis torque requests are based on torque command and torque feedback in an axis torque control mode or on the basis of position, velocity and torque commands and position, velocity and torque feedback in a combined position/torque control mode, or an indirect torque control mode.

Abstract: A binary accelerator is provided for coprocessing operation with a microcontroller. A common memory is shared by the accelerator and the microcontroller for storage of binary equations and equation solutions. The accelerator is formed from a plurality of PAL and LS devices and execute fetched binary instructions in accordance with a Reverse Polish Notation (RPN) system.

Abstract: A pulse width modulation (PWM) control circuit provides for improved implementation of position, velocity and current feedback loops for digital servo control of a multi axis robot. The PWM circuit utilizes a single resistor for sensing joint motor drive current. Circuitry is also disclosed for reducing audible noise and motor heating in large servo motors used for joint arms operated at relatively low PWM frequencies by reducing the motor ripple current.

Abstract: The partitioning of circuitry and software on electronic boards in a robot control is arranged to enable respective controls for varied types of robots to be readily assembled and packaged with use of a few standard boards.The basic control system is formed from an arm interface (AIF) board and a torque processor (TP) board and a servo control (SCM) board. The AIF board has a VME bus terminated in multiple pin connectors for interconnection with the TP and SCM boards and any other boards or additional units to be included in a particular robot control. An AIF connector is also provided for TP board connection on a VMX bus.Robot controls with extended control performance are packaged by including additional boards. For example, the system control board includes a VME bus connector for connection to the AIF board to provide a robot control with higher control capacity.

Abstract: A digital control provides adaptive feedforward torque control for a robot having a plurality of arm joints. An electric motor drives each of the robot arm joints and a power amplifier supplies drive current to each motor under controlled operation.Each joint motor has feedback control loop means including position and velocity control loops driving a torque control loop in accordance with position commands to generate motor commands for controlling the associated power amplifier. The motion of said joint motor generates position and velocity feedback signals respectively for combination with the position and velocity commands to generate an error signal as a torque command for each of the torque control loops from the corresponding position and velocity control loops. Load force is sensed at the endmost robot joint.

Abstract: A digital control for a multiaxis robot includes position, velocity and torque controls that drive a motor voltage control loop. Pulse width modulated control signals operate power switches in a power bridge to control the current to each robot joint motor. A single resistor is connected in the bridge circuit to supply motor current feedback needed for control loop operation.

Abstract: A control system is provided for a workcell having a plurality of electric robots and a plurality of workcell equipment items in turn having a plurality of control and sensor devices associated therewith.Respective electronic robot controllers are disposed at respective workcell locations to operate robots as a part of the workcell process. Each robot controller has a floppy disk or other means for loading program data for one of the robot controllers.A first input/output control module is disposed at another workcell location and it has connected thereto as inputs a first group of the sensor devices and as outputs a first group of the control devices. Second and third input/output control modules are disposed at additional workcell locations and have connected thereto as inputs second and third groups of the sensor devices and as outputs second and third groups of the control devices.

Abstract: A pulse width moduation (PWM) scheme provides for digital implementation of robot control commands. For this purpose, it provides time stabilized current sampling synchronized to the sampling frequency of the position and velocity loops in the robot control. The PWM scheme enables accurate motor current measurement through usage of a single current sense resistor independent of the number of legs in a power amplifier configuration. This scheme permits commercially available, low cost, power blocks to be used for implementation of robot control system power amplifiers.The PWM scheme is cost effectively implemented in a semi-custom large scale integrated (LSI) circuit which provides the digital interface between a torque loop microprocessor and the drive circuitry for the power handling devices used to apply voltage to the robot axis actuator. Interface and control for three axes is provided by a single LSI device.