Design and Evaluation of a Wheel Dynamometer with Improved Rotational Characteristics

A wheel dynamometer is used to measure and analyze the dynamic load input to the wheels of a vehicle while driving. In this study, a six-beam wheel dynamometer designed to improve rotational characteristics was developed, and its characteristics were evaluated. A finite element analysis was performed to predict the output strains and the coupling strains for each force or moment component, and a Wheatstone bridge circuit was properly configured with 24 shear gages. By introducing the concept of redundantly combining unit load cells, an excellent wheel dynamometer with the characteristic that the coupling strains are all zero was designed. An actual wheel dynamometer was fabricated using a domestic automobile as a model, and characteristic tests were conducted using a uniaxial deadweight machine. The measured output strains significantly matched with the strains by finite element analysis within 5.3%. As a result of compensating for the effect of eccentricity of the load jig, a wheel dynamometer with excellent performance was developed, with a maximum coupling error of 6.2% and most of them within 2%.