Basic EtherCAT control test of 4 axis SCARA robot based on SOEM and ruckig...
A web based visualization tool is available here
Inverse kinematics are based on this paper. You can find the implementation in src/Robot/IK/scara.cpp and interactive desmos demo here.
You need a linux platform prepared for realtime:
Install the tuned service then place the files in this folder into /etc/tuned/your-profile-name
You must check that the isolated and general purpose cores listed in realtime-variables.conf match your system or it wont boot again.
And some Delta B3-E servo drives, although you can use any drive after checking the PDO mapping.
Control is done over NATS:
# Receive status payload (250Hz broadcast rate)
nats sub 'motion.status'
{
"alarm": true,
"diagMsg": "",
"drives": [
{
"actualTorque": 0.0,
"controlWord": 0,
"errorCode": 33072,
"fault": true,
"followingError": 0.0,
"lastFault": "Drive 1 error code 33072",
"slaveID": 1,
"statusWord": 1560
},
...
],
"ethercat": {
"compensation": 4,
"integral": 324,
"interval": 1000000,
"sync0": 49160
},
"otg": { "result": 0 },
"pose": {
"alpha": 96.4540360062657,
"alphaVelocity": 0.0,
"beta": -66.03271506126215,
"betaVelocity": 0.0,
"phi": 0.0,
"phiVelocity": 0.0,
"r": 59.578679054996456,
"theta": 0.0,
"thetaVelocity": 0.0,
"x": 149.98383853124818,
"y": 300.0034076877155,
"z": 0.0
},
"run": false,
"state": "Idle"
}
# Start motion tracking
nats pub 'motion.command' '{"command": "start"}'
# Interrupt tracking
nats pub 'motion.command' '{"command": "stop"}'
# Reset homing or alarms
nats pub 'motion.command' '{"command": "reset"}'
# Follow position (time optimal)
nats pub 'motion.command' '{"command":"goto","pose":{"x":150,"y":300,"z":100,"r":0}}'
# Move linearly (indirect, jerk limited)
nats pub 'motion.command' '{"command":"moveLinear", "duration": 5.2, "pose":{"x":150,"y":300,"z":100,"r":0}}'