Research On Electrical Dynamic Load Emulation For Powertrain Test Bench

Bench test is an important part of modern vehicle development. Powertrain test bench is an platform for research, develop and testing of clutch and transmission. The test results are reasonable when test unit operates in a similar condition as real vehicle. With the improvement of electric and control technique, most benches use motor as dynamometer to achieve better respond and dynamic performance. Research on dynamic load emulation is a hot point of test bench study. Traditional torque control method requires an accurate modeling of bench system, which is hard to realize in engineering application. A close loop speed control method can follow desired speed command, but will change dynamic characteristic of dyno system. Theoretically, a method which combines close loop speed control and open loop torque control can achieve good dynamic performance and well speed tracing ability.The paper studies an application of load emulation on a motor-driven test bench. The basic methods of vehicle testing are resented to derive the meaning of bench test. Current researches on load emulation are discussed. The structures of test bench, control method of motor and sensor position are introduced in the paper. A modulate structure of vehicle and test bench dynamics is presented for specify load emulation target. Some algorithms of load emulation are analyzed to examine their priority and defectiveness. Experiment is performed to validate load emulation methods. Results show that the method combines close loop speed control and open loop torque control can emulate dynamic characteristics of target system on test bench. The limitations and future improvement of paper are presented as the final part.