- Hardware setup:
– EK1100 ethercat coupler.
– Four EL2008 modules for 32-bit digital output.
– Four EL1018 modules for 32-bit digital input.
– Two DC 24V SMPS
- Software setup:
(1) Debian Jessie and Xenomai dual kernel.
(2) Ubuntu 14.04 and RT-preempt kernel.
(3) Debian Wheezy and RTAI dual kernel.
- Test result: cycle-time 190 us in DC mode.
- Hardware structure: simple but flexible.
- PCI IP core: open-source. Downloaded from opencores.org
- Data transfer speed of the PCI digital IO board without using DMA: 66.8 Mbits/sec on 33MHz 32-bit PCI bus.
Building and running openPOWERLINK v2.1.1 demos on Linux PCs
- demo_cn_console, demo_mn_console: run without any problem.
- demo_mn_qt: crashes. —> bug fixed in openPOWERLINK v2.1.2
2. Ubuntu 14.10, Ubuntu 12.04, Debian Jessie :
- demo_cn_console, demo_mn_console, demo_mn_qt: run without any problem.
3. Kernel 3.18.11-rt on Ubuntu 14.10:
- locktorture.c should be patched to compile the kernel.
- RCU-related kernel options should be properly set to prevent softirqs messages while running the demo.
Details of the “Ethernet Powerlink” can be found at
USB Comminication speed between a host computer/board and the motion-control FPGA.
1. Experiment setup.
- 1530-byte round-trip test.
- Asynchronous FIFO mode of the FT2232H.
2. Experiment results.
- PC running a plain Linux: about 50 Mbits/sec.
- Raspberry Pi 2 running a realtime Linux: at least 30 Mbits/sec.
- Reads the status of external sensors and servo drives and sends it to the PC.
- Receives commands from the PC and writes them to external devices and servo drives.
Internal structure of the motion-control FPGA:
- command-pulse-generator module: generating command pulses for servo drives.
- quadrature-counter module: counting quadrature pulses from servo drives.
- output-latch module: latching parallel output signals to external devices and servo drives.
- input-latch module: latching parallel input signals from external sensors and servo drives.
- USB-interface module: reading/writing data from/to USB bus.
- Finite-state-machine module: controlling the data flows among the above modules.
Ink jets and laser printers need 2D motion control. Who sells ink jet or laser printers ? robot companies, motor control companies, or motion control companies ?
Do you really believe control is the most important thing of robot controllers ? I am familiar with classical and“fancy” control theories and I have a long list of control projects in which I have been involved. If you have an universal controllers that work well on every control application, please let me know. I often day-dream of such a controller.
You can religiously believe motion control is the flesh and blood of the 3D printers, if you want. I read a very entertaining post, saying a medical robot company has a core technology needed for 3D printers. Of course, that person is a stock holder of the medical company.