MOTION CONTROL
The new multi-processor ST controller, K11R Mk5 provides all the power and intelligence to control a robot arm using a hierarchical architecture of CPU (central processing unit), DSP (digital signal processor) down to individual axis processors. The controller has a built-in programming language called Roboforth and is easily programmed using a PC connected via a serial cable or USB. A simple teach pad is provided for fine positioning but the majority of functions are invoked from the computer. There is no need for a separate PLC. The controller can also be commanded from a supervisory computer as part of a larger system.

INPUT-OUTPUT
The K11R5 can also connect to, interface with and control all kinds of equipment such as pneumatics, feeders, plate stacks, conveyors, molding machines and synchronize all activities with the robot. There is an easily used input output register which can be expanded with a range of plug-in cards for analog or digital interfaces, serial, opto-isolated buffers and so on. This means you can easily arrange interlocks or control devices or take measurements while the robot is in motion. And you can add and control additional stepping motor devices such as indexing carousels, accurate bi-directional conveyers. Some clients use a K11 controller without a robot to control complex equipment and program it quickly and easily using Roboforth. You can also use it to control any machine with up to 6 stepping motors, with or without encoders. Additionally the controller has timers, interrupts and timer interrupts all programmable with the ease of Roboforth.

SYSTEM ARCHITECTURE
The controller uses a fast pipelined CPU communicating with a DSP which in turn controls motion via intelligent drive modules, thus freeing the CPU for overall program control and I/O. High voltage MOS micro-stepping drives control the robot motors accurately and without resonance yet pack power and high speeds when required. Robot feedback comprises encoders which connect back to the DSP. The CPU compares these counts with the software counts and makes corrections or halts motion as necessary. For example in the event of a stall robot motion is aborted and an error is announced (which is safer than most robot systems). Both the programming system and user's software are stored in flash EPROM but run in fast static RAM.
A computer is needed to program the controller which can be removed after programming is complete. Connection is via serial RS232 or USB (option). During programming data and procedure are saved both to disk and to controller Flash ROM. Once programmed the controller will run on its own without a computer.

FEATURES
Max. number of axes 6
Max locations stored approx 4,000
Max outputs 6 expandable to 54 buffered and opto-isolated.
Max inputs 3 expandable to 51 incl. opto-isolated.
Baud rate programmable 1200 to 56000 baud, default 19200, optional USB
Weight 11.5Kg
Temperature -10 to +40 deg C

AXIS DRIVES
Axis drives are intelligent MOSFET chopper drives that energize the motors with PWM (pulse width modulated) constant current which recirculates at rest to prevent heating. Microprocessors automatically compensate for low and mid-range resonance. At low and medium speeds they vary phase current sinusoidally in a manner called micro-stepping. As speeds increase they 'morph' from micro-step to full step so that the motors maximum current rating is achieved. See the diagrams below - fig1 shows low speed sinusoidal control of position. You can see the PWM chopping. Fig2 shows the change to full step in progress.

OPTIONS

  • Analog input and output
  • 48 line digital input/output
  • Opto-isolated input and output conditioners/drivers
  • Conveyor tracking support
  • Grip confirmation
  • Pulse modulated gripper motor drive.

    Multi-function I/O expansion brief specifications:
    Analog inputs 4 channels, +/- 10 volts, 12 bits
    Analog outputs 2 channels, +/- 10 volts, 12 bits
    Digital I/O 5 volts CMOS, 48 bits, programmable as output and/or input
    Options 8-line opto-isolated input module, 8-line opto-isoated output module
    Up to 2 cards per controller.
    link to relevant part of manual

    • SOFTWARE
    The K11R5 controls the robot using a software system written in FORTH called ROBOFORTH II. Drivers and interfaces with the DSP and I/O are coded in fast, efficient, interrupt-free machine language but the user interface is high level, using easy to learn English language commands. A computer is needed to program the controller and this can be removed after programming or used as a supervisor running software which sends commands to the controller. To program the robot a Windows based GUI (graphical user interface) project management system, ROBWIN is run in the computer. The resulting program and data are downloaded into the controller which compiles them into a very small memory space, compact and highly efficient.

    ROBOFORTH II is a fourth generation list-oriented language based on FORTH. It comprises a dictionary of some 450 words which are strung together in meaningful ways depending on what has to be done. Programming is done by extending the dictionary by defining new words in terms of words already in the dictionary. Program control (branching etc) is structured as in a third generation language. Programs (or rather new word definitions) are entered and edited as files in the computer then downloaded to the controller. With these tools the robot can be adapted to a diverse range of applications.

    Among the many features of ROBOFORTH is an object database with which the system keeps track of every object handled and where there are. Software interlocks prevent errors and mistakes such as the robot placing an object where there already is one. All errors can be reprogrammed, for example what happens if the emergency stop is pressed or if the robot encounters an obstruction.

    ROBOFORTH has been under continuous development since 1981 and is probably the most extensive and powerful robot programming system in the world.

    SAFETY
    Each controller is supplied with class 2 E-stop, class 1 and optional class 0 stop circuits. Class 2 E-stop is programmable so that what happens on hitting stop can be strategically determined. The stop circuit is extendable round the work space and may be connected to light curtains etc. The controller is CE marked and for EMC complies with EN55022 class A and FCC part 15 sub-part B class A.