A2 New Motor Testing

Owned by Yu-Ming He
Last updated: Oct 03, 2024
2 min read

Test Overview:

Purpose of the test: to verify new motor actuator set up and see if the EC90 600W can output larger required torque values.

3 tests will be performed at each weight and the current will be measured: static at 90 degrees (parallel to floor), velocity moving CW (upwards) from 90 to 0 degrees and stopping at 0 degrees, and velocity moving CCW (downwards) from 0 to 90 degrees stopping at 90 degrees.

Set up axis 2 test rig with odrive, encoder, and hal effect sensor with 2 limit switches mounted at 0 and 90 degrees triggered by the bolt. Commands will be sent through CAN commands. 24V power source

Important Specs:

Part

 

 

Part

 

 

Maxon EC 90 Flat 600W 30V

Note: Since we’re running it at 24V, spec sheet info might not reflect actual results

Nominal Torque: 1.56 Nm

Nominal Current: 10.5 A

 

GAM GSL-CS-020

Nominal Output 49Nm

Max Acceleration Output: 87 Nm

Emergency Output 147 Nm

 

Weight (kg)

Equivalent Torque (90 degrees, Static)

Expected Current (A)

(((T/120)/0.85)/0.138)

Current (static ad 90 Degrees) (A)

Current (with -2 velocity) (A)

Weight (kg)

Equivalent Torque (90 degrees, Static)

Expected Current (A)

(((T/120)/0.85)/0.138)

Current (static ad 90 Degrees) (A)

Current (with -2 velocity) (A)

5.5

27.4

1.9

 

Can we output a current graph from Odrive?

8.1

40.4

2.9

 

 

10.4

51.8

3.7

 

 

12.7

64.3

4.6

 

 

15

74.8

5.3

 

 

18

89.7 (Max Acc of Gearbox)

6.4

 

 

20

100

7.1

 

 

25

130

9.2

 

 

29.6

148

10.5 (Nominal output for motor)

 

 

Test Procedure:

  1. Set up actuator 2 with Saheed’s testing rig consisting of 0.508m metal arm attached to axis where load would be applied that corresponded to torque being applied on the gearbox + motor.

  2. Set up active cooling using a fan

  3. Connected axis to power supply, odrive and hal effect to input closed loop into arm when testing. Commands will be sent using CAN through the jetson.

    1. First measurement: Actuator supports the weight horizontally at 90 degrees, record current

    2. Second measurement: Actuator moves upwards using velocity control (2), stops at 0 degrees when limit switch is hit. (Ask Billy if we can get record continuous current reading from odrive

    3. Third measurement: Actuator moves downwards using velocity control (2), stops at 90 degrees when limit switch is hit.

  4. Current draw from Odrive is monitored from the power supply while current draw fro the motor would be examined from current probe

  5. Test would first measure the current draw at static to just hold up the load, then velocity control of -2 would be applied and highest current draw would be taken

Test results: