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 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 modular digital robot control includes an electronic arm interface board provided with circuitry for performing robot arm dependent functions. Included are circuitry for generating power amplifier control signals in response to input voltage command signals and circuitry for processing and manipulating position, velocity and motor current feedback signals.An electronic torque processor board is provided with paired torque microprocessors for operating each of respective torque control loops for respective robot joint motors. The torque microprocessors generate the voltage commands in response to input torque commands and feedback motor current signals.An electronic servo control board is provided with paired position/velocity microprocessors for operating position and velocity control loops for the respective joint motors. The position/velocity microprocessors generate the torque commands in response to input position commands and feedback position and velocity signals.

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 digital position and velocity feedback system is provided for a multiaxis robot control and it employs an LSI chip to process incremental position signals for position change and velocity computations. At low speeds, velocity is computed from the reciprocal of elasped time. At higher speeds, velocity is computed from the rate at which incremental position signals are generated.

Abstract: Circuitry is provided for applying a pulse width modulation (PWM) scheme to a brushless DC motor that operates as a robot axis drive. A pulse width modulation (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 brushless drive application circuitry provides for application of the PWM control outputs to commutate the motor energization from winding pair to winding pair.

Abstract: A digital robot control is provided with position/velocity and torque control loops with microprocessor servo controllers in each. The position/velocity servo controller includes two microprocessors that operate as a servo engine in providing position/velocity control for six robot axes. One microprocessor operates as a manager to perform data processing and coordination tasks supportive to position/velocity control. The other microprocessor performs position and velocity servo calculation tasks and operates as a slave processor to the position/velocity control manager. The programming for the position/velocity control sends manager position and other commands and position and velocity feedback from other control levels to the position/velocity calculator and sends torque commands received from the calculator to the next lower control level. The calculator employs position/velocity control algorithms in making torque command calculations.

Abstract: A digital robot control is provided with cascaded position/velocity and torque control loops with microprocessor servo controllers in each. The servo controller includes two microprocessors that operate as a servo engine in providing motion control for six robot axes. One microprocessor is structured to perform data processing and coordination tasks. The other one performs calculation tasks and operates as a slave processor to the first.

Abstract: A digital robot control includes a position/velocity microprocessor control and a torque microprocessor control for each of multiple robot axes. Digital position, velocity and motor current feedback signals are generated from motor sensor signals for use in making microprocessor control calculations. Another motor sensor generates an overlimit signal when motor temperature rises above a limit value to indicate excessive motor current. The torque microprocessor makes a backup motor energy calculation from the feedback motor current signal from each joint motor and compares the result to a stored motor energy limit. The robot is shut down if either limit is exceeded.

Abstract: A robot is provided with an arm having a plurality of motor driven joints. A power amplifier supplies drive current to each joint motor. Respective digital feedback control loop arrangements generate voltage commands from which signals are generated to operate the power amplifiers.Digital motor current, position and velocity feedback signals are generated for position, velocity and torque control loops in the digital feedback control loop arrangement. System resource facilities provide general support for the operation of the digital feedback control loops and include three separate communications controllers, a dual port microprocessor interfacing memory, a time stamp clock, a program memory and a nonvolatile data memory.A system level microprocessor based system or a microprocessor based position/velocity control system executes motion software from the program memory means according to whether the user desires an expanded performance robot control or a basic robot control.

Abstract: A digital robot control includes a position/velocity microprocessor control and a torque microprocessor control for each of multiple robot axes. Digital position, velocity and motor current feedback signals are generated from motor sensor signals for use in making microprocessor control calculations. A backup velocity determination is made for each joint motor by the torque microprocessor from the motor current feedback, the motor command terminal voltage and the motor resistance and inductance. The robot is shut down if the difference between the feedback and backup velocity values exceeds a predetermined limit.

Abstract: A completely digital robot control operates at a predetermined sampling rate. The robot arm has a plurality of joints with each driven by an electric brushless or brush-type DC motor which is in turn supplied with drive current by a power amplifier bridge circuit having power switches connected therein to supply motor winding current in the forward or reverse direction.Incremental or absolute encoders and tachometers provide for generating digital position and velocity feedback signals generated synchronously with the sampling rate. Digital motor current feedback signals are also generated synchronously with the sampling rate.Paired position/velocity microprocessors generate torque commands for each of the robot axes at the sampling rate in response to the position commands and the position and velocity feedback signals. Paired torque microprocessors generate motor voltage commands for each of the robot axes at the sampling rate in response to the torque commands and the current feedback signals.

Abstract: A digital robot control is provided with cascaded position/velocity and torque control loops with microprocessor servo controllers in each. The servo controller includes two microprocessors that operate as a servo engine in providing motion control for six robot axes. One microprocessor is structured to perform data processing and coordination tasks. The other one performs calculation tasks and operates as a slave processor to the first.