Test bench for angle of rotation sensors

Referenz WSK Elektronik

Prüfstand für Drehwinkelsensoren

High accuracy test stand for measuring angle of rotation (torque) sensors

Test specimen

In modern motor vehicles, the formerly hydraulic power steering is replaced by an electric drive. This consists of a control loop of torque sensor on the steering wheel, control unit and servomotor. During the steering process, the torque sensor detects that increased force is being applied to the steering wheel and supports this by means of a servomotor on the steering gear. In practice, this torque sensor consists of a torsion shaft with a highly sensitive rotation angle sensor that measures very small angles. These angle of rotation sensors are measured and calibrated on the test equipment manufactured by us.

Testing device

The test equipment developed by us consists of up to 4 high-precision drive units, the drive control, the measurement technology with PC system and software as well as a climate simulation chamber. The device measures the sensors (up to 4 in parallel) according to their specification (characteristic curves over the entire temperature and measuring range) and performs the calibration.

Since the DUTs have a very high resolution (only very small twists are possible at the steering wheel/torsion bar), the test equipment must measure the measurement angle very accurately as a reference. The angle encoders installed in our test drive on two axes per drive record the angle of rotation with a resolution of 0.0005°, i.e. 0.5 thousandths of an angular degree, which corresponds to 1.8 angular seconds or 720,000 positions per revolution! This resolution is available over a full 360°x n. These angle encoders are recorded synchronously with the measurement signal from the DUT during rotation over the DUT's measurement range.

The test specimens are mounted in a climate simulation chamber with a quick-clamp fixture and are measured and automatically set up with a 2/3D laser unit. The test drives themselves are located outside the climate chamber and are therefore independent of the test temperature. The climate simulation is controlled depending on the test software and the test specimens are measured and logged at the relevant nominal temperatures. The software with intuitive user interface (on a 24/7 capable industrial PC system) controls and manages the complete test sequence, records and organizes the measurement data. The data is organized in databases on the test computer and can be organized and evaluated by authorized users in the network.


This test facility is a classic example of one of our customized solutions. The customer originally approached us with the test specimen and the relevant characteristic values. From these specifications, we designed the concept and finally constructed and developed the facility. On the one hand, the setup consists of available components such as purchased parts, climate simulation chamber, racks, motor controller and measurement electronics as well as some specially developed assemblies.

The central test drive, with all encoders and angle measuring equipment and actuators was designed and manufactured by us. Even the motor is a special production. Also special parts of the measuring electronics and the central software were developed for this task by us. The complete system was designed and manufactured according to the needs of our customer.

One can see here very distinctive: Even equipment with small quantities (1-10 pieces) and highest measuring accuracy can be realized with reasonable financial effort and relatively short development and production time, if you cooperate with the right partner. Just send us your inquiry. We look forward to hearing from you!