Hardware and software platforms for an industrial robot controller

Hardware and Software Platforms for Industrial Robot Controllers

Aug. 2008

Gyoung Hwan Kim. Ph.D.

gyounghkim@open-robotics.com

 Questions

  • State-of-art robot controllers ?
  • Design concept ?
  • Internals of robot controllers?
  • Next robot controller ?

Robot Programming

  • AL: Stanford Univ., 1981
  • VAL: Unimation, 1980
  • PAL: Purdue Univ., 1981
  • “Robot Manipulators”, R. P. Paul, 1981
  • RCCL: Purdue Univ., 1983
  • Multi-RCCL: JPL, McGill Univ., 1990
    Dead research areaNote that Samsung’s robot language is based on VAL.

Robot Control

  • Kinematics-based control: independent joint control
  • Dynamics-based control: ~1990
  • Direct drive arms
  • Flexible robot control
    Matured research area

State-of-art Robot Controller ?

Robot Controller Developed

Robot Controller developed for SCARA and transfer robots

Design Concept ?

Internals of Robot Controllers ?

Robot Controller Structure

Servo Controller Structures

  • Type 1. Drive interface board + 1-axis drives
  • Type 2. Servo board + “IPM + DC-link”s
  • Type 3. Servo board + IPMs + DC-link
    Note that 1-axis drive = servo processor + IPM + DC-link circuit.

 

Type 1. Servo Controller

  • High-power applications.
  • Conventional control scheme.
  • Commercial 1-axis drives.

Type 1 Drive Interface Board
(developed and tested)

  • TI TMS320F2812 DSP for linear interpolation.
  • FPGA for binary rate multiplication and encoder pulse counters.
  • 6 channel incremental encoder inputs (electrically isolated).
  • 6 channel pulse outs for 1-axis drives (electrically isolated).

 

Type 2. Servo Controller

  • High-power applications.
  • Flexible control schemes.

Type 3. Servo Controller

  • Low-power applications.
  • Flexible control schemes.

Type 3 Servo Board

  • The most powerful , flexible and advanced servo controller used in commercial industrial robot controllers.
  • Software –only implementation of position, velocity, and current control.
  • 1KHz current loop and 0.5 kHz position and control loop.
  • DSP load is less than 30%.

Type 3 IPM
(Intelligent Power Module)

Type 3 DC-Link Circuit

Robot Controller Structure

Main Processor Board

  • Hardware: X86 motherboard + PCI boards
  • Software: Real-time Linux (RTAI)

CPU Board
(off-the-shelf product)

  • Compact size and low power consumption: Mini-ITX board with an 1GHz VIA CPU.
  • 3 PCI board using a riser card.

Riser Card for 3 PCI Slots

 PCI Boards

  • High speed 4-port serial board: two RS232 ports and two RS422 ports.
  • CC-link PCI board: TI TMS320C2812 DSP with a dual-port memory.
  • RTAI RTDM drive driver for the serial board and Linux device driver for the CC-link board are also developed.

Four-port Serial PCI Board

CC-Link PCI Board

Profibus PCI Board

Parallel I/O board

  • Intelligent parallel I/O board – TI TMS320F2812 DSP.
  • Electrically isolated 24 inputs and 24 outputs.

Main-to-Servo Interface

  • Main processor to servo controller interface:
    – electrically isolated.
    – high-speed (2.5M bps) serial interface – RS422.

Tested Configurations

  • One SCARA robot + one X-Y robot.
  • Three X-Y robots.
  • One transfer robot with one driving axis.

SCARA + X-Y robots

LCD Transfer Robot with a Driving Axis

Next Robot Controllers ?

  • For larger robots, a drive interface board is developed.
  • If needed, RCCL can be used.

Conclusion

  • A flexible robot controller is developed and tested with SCARA robots and transfer robots.