A Methodology for Laboratory Testing of Truck Cab Suspensions

This work pertains to laboratory testing of truck cab suspensions for the purpose of improving in-cab ride quality. It describes the testing procedure of a complete truck cab suspension while still being mounted on the vehicle. It allows for testing with minimal amount of resources, limited to two mobile actuators and minimal modifications to the stock vehicle. The actuators can be attached to any axle through a set of modified brake drums and excite the drive axle in a vertical plane. The excitation signal sent to the actuators can be in phase for a heave type motion or out of phase for a roll motion. The chassis shock absorbers are replaced with rigid links to prevent the actuator input from becoming filtered by the primary suspension. This allows the input to reach the cab suspension more directly and the cab to be excited across a broader range of frequencies. The laboratory setup allows for easy calculation of transfer functions, frequency response and other measures vital to the successful development of a better cab suspension without the complications involved in actuating through the primary suspension. The proposed test method makes it easy to quickly revert the cab and the primary suspension to their original configuration and make the vehicle ready for road operation.