Electric Power Steering (EPS) technology uses electric motor instead of hydraulic pressure to assist automobile steering.

Torque which is the driver’s power to control the steering wheel is transmitted to torsion bar and rack & pinion gears. This power then gets detected by torque sensor and transmits to the ECU. ECU then applies electric current (amount of power assist) according to the torque and car speed.

4Q EPS Motor Test stand

4Q EPS Motors Test System is a turnkey stand-alone test bench to measure all require performance tests for EPS motors. The system can be found in tests lab and in production floor as EOL performance test bench.


Passive (de-energized winding) Tests:

  • Winding resistance & inductance line-to-line
  • Back EMF Constant
  • Cogging & Friction Torque
  • High Speed Friction Torque
  • Low Speed Friction Torque / Magnetic Drag


Active (energized winding) tests:

  • Ripple Torque with order analysis.
  • Torque Constant

Full tests: Torque, Speed, current, voltage, Power In, Power out and efficiency.

Speed Vs Torque
Time Vs Torque

4Q-EPS is designed to supply high-speed and high dynamic performance using ‘High Speed’ asynchronous vector motors as load machines.

The system is also designed to have low vibration level and give easy tools for the alignment of the MUT in the test bench. All measurement items such as torque and speed can be easily calibrated using the system software interface along with the electrical measurement of Voltage and Current that can be calibrated also.

Ambient temperature0 to 50℃
Surrounding Humidity90%RH or below
Power input1Ø, 230VAC 50/60Hz
Power input3Ø, 380VAC 50/60Hz
       Speed range0 to 10000 rpm
       Angle0.09° (4000PPR)
       RotationCW and CCW
       Torque / Speed / Cogging / Friction / Rotation / Current / Voltage / Power In / Power Out / Efficiency values
All Tests vs. speed or torque display
Harmonic analysis – 1-150 order


Model Number4Q-EPS 104Q-EPS 204Q-EPS 50
Rated Torque10 [Nm]20 [Nm]50 [Nm]
Accuracy Scale0.1 % F.S
Ordering No:  4Q-EPS-___  
4Q-EPS-10: 10[Nm] 
 4Q-EPS-20: 20[Nm]
4Q-EPS-50: 50[Nm] 
Example4Q-EPS-20 mean 4Q EPS test system with 20Nm range.
For more details contact us