The new EtherCAT Dual CAN (EDC) hand sees a sizeable increase in performance for the world leading Shadow Dexterous Hand.
The EDC version of the motor hand is identical to a standard CAN bus motor hand, except that the single CAN bus which serves all of the electronics has been replaced by an EtherCAT network and two CAN buses.
A CAN bus has a bandwidth of about 600kB/s, allowing a servo rate of about 100Hz internal to the hand.EtherCAT has a bandwidth of 7.5MB/s, allowing a servo rate of 1000Hz.
The following table shows the performance of the new EDC hand compared to the CAN hand in various areas:
| CAN hand | EDC hand | |
|---|---|---|
| Sensors | ||
| Joint Sensor update rate | 100Hz | 1000Hz |
| Tactile Sensor update rate | 100Hz | 1000Hz |
| Motor Torque Sensor update rate | 30Hz | 500Hz |
| PID Control Loops | ||
| Torque control loop rate | 1000Hz | 5000Hz |
| Position control loop rate | 100Hz | 1000Hz |
| Velocity control loop rate | - | 1000Hz |
| Torque Controlled at | Motor | Motor |
| Position Controlled at | Motor | Host |
| Other Features | ||
| Friction Compensation | No | Yes |
| Firmware bootloading | No | Yes |
| 6-axis IMU | No | Yes |