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.