In-Vehicle Engine Torque Model Validation

Many powertrain control systems require knowledge of engine torque output in order to perform functions such as transmission pressure management, shift torque management, and traction control. However, engine torque sensors are usually not a viable option for mass produced vehicles due to the constraints of cost, packaging, durability, and accuracy. Therefore, many engine control modules (ECM) must settle for software models that estimate engine torque. This paper describes an in-vehicle torque sensing system that was created to supplement the engine dynamometer development and validation of an ECM torque model. The reasons for requiring in-vehicle torque measurement are described in detail along with sensor selection criteria, sensor characteristics, mechanical integration, electrical integration, and test results.