Hybrid Simulation: mHIL Steer

• An MTS steer test system with customer steering sub-system installed on it represents the mechanical hardware, which is put in place of modeled steer element(s) within a vehicle simulation model
• The steering sub-system consists of the steering rack and pinion assembly, tie rods, tie rod ends, intermediate steering input shaft and steering column, along with necessary fixturing to simulate a realistic vehicle configuration.  
• The steering system is actively controlled by an ECU . 
• The steering system and the ECU are driven in the modeled vehicle on a modeled track as if they were on a real vehicle and track.

The steering test system applies loads and/or displacements to the mechanical steer hardware based on inputs from the vehicle simulation model, measures the hardware response, and then sends these responses back to the vehicle simulation model. The mechanical hardware is included “in the loop” with the simulated vehicle.

The advantages of using the MTS mHIL Hybrid Simulation technique in the vehicle development process include:

• Analysis / CAE
  • Real physical parts can be substituted for difficult-to-model components when performing virtual simulations
  • Enhanced characterization to support better model development
• Objective and repeatable results
  • Very repeatable tool to support a more efficient track program
• Generate accurate test results faster and earlier in the development process:
  • Don’t need to wait for road loads or full vehicle prototypes
  • Evaluation and validation at both the sub-system and vehicle level
  • Rapid testing of platform and geographic variations
  • Fast validation cycles
• Safer and less costly alternative to the track:
  • Expected and unexpected fault conditions easily and safely evaluated in a laboratory environment
  • Reduce the number of vehicle prototypes required
  • Reduce vehicle instrumentation and data acquisition costs
  • Reduce track dependency associated costs