Measurement of Driver-Vehicle Multiloop Response Properties with a Single Disturbance Input

Multiloop response properties of controllers are, in general, very difficult to obtain because an independent forcing function is needed for each describing function to be measured, and interpolation procedures may be required to obtain intermediate describing functions at common frequencies. Even then, a certain amount of untangling is required before the final results are obtained. When the loops that are closed and the nature of the describing function forms adopted in each loop are known or hypothesized, matters can be made much simpler. Then, the quantitative values of the individual describing functions can be readily identified using appropriate closed-loop describing function measures and decomposition procedures. Two examples are provided for the measurement of driver-vehicle multiloop response properties using a single disturbance input. The validity of the procedure is based on current multiloop operator adjustment rules and is made plausible by comparison with experimental data.