SUNCAR Sport Lotus Evora – ETH Focus Project

The SUNCAR Sport is based on a Lotus Evora. An electric drive, including all necessary components and software, was installed in the SUNCAR Sport. Additionally, an active electric steering system was developed and installed.

Furthermore, a concept for integrating a range extender was developed. However, this currently only exists in theory. A major highlight is that the SUNCAR Sport has road approval. It deservedly received this, proving its capabilities by participating in the Bertha Benz Challenge and the Wave Rally, among others.

To achieve the desired improvements in driving behavior, a yaw rate controller with feedback, combined with traction control for each rear wheel individually, was implemented. First, the nonlinear vehicle model, created with multi-body simulation software to evaluate driving behavior and virtually test the controller, is presented. Subsequently, the measurement results, recorded during three different driving maneuvers on a test track, are discussed. The measurements demonstrate the effectiveness of the controller, but also its limitations, primarily caused by the occurrence of slip. The test driver noted improved turn-in behavior and better vehicle control.

Instead of the internal combustion engine, two powerful electric motors are installed in the rear of the vehicle, enabling active torque distribution to the rear wheels. To achieve the desired improvements in driving behavior, a yaw rate controller with feedback, combined with traction control for each rear wheel individually, was implemented. First, the nonlinear vehicle model, created with multi-body simulation software to evaluate driving behavior and virtually test the controller, is presented. Subsequently, the measurement results, recorded during three different driving maneuvers on a test track, are discussed. The measurements demonstrate the effectiveness of the controller, but also its limitations, primarily caused by the occurrence of slip. The test driver noted improved turn-in behavior and better vehicle control.

The integration of an active, electric steering system into the electrified Lotus Evora enables a greater range. Central topics during the conversion from hydraulic power steering included both theoretical considerations for the structural integration of the new steering gear and design work on the housing, the rack, and the mounts. The implementation of electrical integration, communication, and the creation of a test bench were discussed in detail. The advantage of electric power steering lies in lower power consumption due to the elimination of a continuously active compressor.