Motion and Position Controller
The MARS8 units can also control any other system equipped with up to 8 DC motors (5A/30VDC max) with incremental position encoders (TTL/RS422 signal levels). For example, OPTEN translation tables or OPTEN turn tables. Up to three tables combinations could be controlled by simpler MARS2 units as well.
|MO_CPU1 (155mm x 80mm x 15mm)|
|Click to read more about MO_CPU1 board|
|CPU mc68376 @ 21 MHz, 1 or 2 MB of SRAM, 1 or 2 MB of FLASH,|
|32 kB of CMOS SRAM and RTC which are battery back-upped|
|headers for BDM and on two sides of board almost all MCU pins|
|IIC communication interface with PCF8584|
|isolated RS-232, RS-485 and CAN communication|
|ispGAL is used to lower number of used chipselects|
|MO_PWR1 (128mm x 93mm x 25mm)|
|isolated power stage with 8 full bridges for DC motors up-to to 30 VDC|
|and 5 AMPs with over-current protection|
|DCDC converter from 15 up-to 30 VDC to 5 VDC for CPU, 5 VDC for isolated|
|communications and helper supply for bridges.|
|8 channel 8-bit ADC for current measurement|
|MO_CTR1 (105mm x 80mm x 12mm)|
|eight 24-bit IRC counters with two index and mark inputs per motor|
|TTL or differential RS-422 encoders could be used|
|some ADC inputs, SPI connector and some logic signals|
|and ability to connect our local keyboard on 8-bit bus|
Block diagram of three boards system (PDF file)
The basic software for velocity and position control is developed. There is trapezoid speed profile position generator and more types of PID controllers. Up to eight servo motor axes can be controlled with sampling frequency 1 kHz. Unit is directly compatible with MAXON 10 - 70 W motors equipped with HEDL or HEDS incremental encoders.
More complex systems with local keyboard, display, digital and analog I/O control, coordinated movement and CAN or RS485 network integration can be prepared on demand.
System can be inbuilt into box of size 120mm x 240mm x300mm. All motor connectors and some I/O connectors of control electronic kit are accessible at front panel of the box. 200 Watt power supply is placed in box too.
Some parts of control system can be produced and used stand-alone. The MO_CPU1 boards can be used for laboratory instrument or other embedded devices control or for educational purposes.
Source code for the motion controller can be found at GitLab repository https://gitlab.com/pikron/projects/mo_cpu1/mars-mo_cpu1