Estimation of lateral acceleration by polynomial approximation

Vehicle lateral acceleration is used for suspension and brake control. To reduce costs, the lateral acceleration is computed using steering wheel angle, vehicle speed, and vehicle specific parameters. The direct implementation of this computation is costly from a microprocessor cycle time point of view and is not feasible in a custom application specific integrated circuit (ASIC). This paper describes the derivation of the equations used to compute lateral acceleration from two second degree polynomials efficiently in hardware as well as the required hardware multiplication and shifting accumulator units programmed into a MAX 7000 electrically erasable programmable logic device (EPLD) using Altera Hardware Description Language (AHDL) in the MAX+PLUS II design environment. This design can be integrated within a Configurable Application Specific Microcomputer (CASM) or directly with the steering wheel sensor.