Abstract: A vehicle force measurement system for determining the force output of a vehicle independent of the radius dimensions of the driving wheels of the vehicle. A fifth wheel is utilized to provide an accurate vehicle speed reading. Torque and RPM sensors mounted to the driving wheels of the vehicle are used to determine the total power output of the vehicle and the total force output of the vehicle is determined by dividing the total power output by the speed signal from the fifth wheel.

Abstract: A dynamometer system for simulating road load and vehicle inertia forces for testing vehicles in place. The system includes a DC motor power absorption unit (PAU) and a microcomputer based system controller for controlling both the road load and inertia forces simulated by the PAU. A non-declutchable flywheel is used to simulate mechanically a constant amount of inertia to minimize the power requirements of the PAU. The control scheme is designed to implement the classic dynamometer control expression (F=A+Bv+Cv.sup.2 +I dv/dt) in a novel manner with a minimum amount of delay time. The microcomputer is provided with the following measured functions: speed, acceleration, and a torque signal. The total force output to be simulated by the PAU is determined by first calculating the actual force output of the vehicle, and then determining the percentage of the total force output that should be assigned to the PAU.