附录附录1英文原文High-Performance Automotive Engine Control in Engine Tester Michitaka Hori (Member IEEE) Masahiko Suzuki (Member IEEJ)Masakatsu Nomurawember IEEE) Masayuki Terashimamember IEEE)Meidensha CorporationAbstractThis paper presents a novel decoupling control method on the engine torque control for the automotive engine tester. The engine tester is mainly composed of a dynamometer control system and an engine control system. The conventional engine tester has the problem that the performance of the engine torque control system is deteriorated by the influences of the interference between the dynamometer speed control system and the engine torque control system. The authors proposed the practical engine torque control system based on an observer and an identification system to eliminate the inference of dynamometer speed control system. The effect of observers parameters error on the engine torque estimation response was analyzed. According to the result of this analysis, a practical method is proposed to identify the engine inertia moment and the shaft spring coefficient that are parameters of the observer. The authors confirmed that the proposed decoupling engine torque control system realized a robust control system from the interference with the dynamometer speed control system through simulation and experiments.I . IntroductionRecently, environmental protection is one of the most important problems in the world, and the exhaust gas from automobiles is also strictly regulated by law. Under such circumstances, the performance of automotive engines is improving year by year, and engine testers, which are used to measure engine characteristics, are required to have high control ability. However, in the conventional torque control of engines, dynamometer torque or shaft torque is applied as a feedback variable instead of engine torque because the engine torque cannot be detected directly because of its structure. As a result, there is a coupling between torque control and speed control. For the reason given above, it has been difficult to attain high control ability in the conventional systems. The authors have proposed an approach to eliminate an interference component from the dynamometer speed control system, through estimation of engine torque using an observer and identification system. The effect of observers parameters error on the torque estimation response was analyzed. According to the result of this analysis, a practical method is proposed to identify the engine inertia moment and the shaft spring coefficient which are parameters of the observer. We confirmed that the proposed engine torque control system realized a robust control system from the interference with the dynamometer control system. The effectiveness of this control system has been confirmed through simulations and experiments.II . Configuration of Engine Tester and Test methodA. Configuration of Conventional Engine TesterFig.1 shows a configuration of a conventional engine tester. The engine tester consists of an engine to be tested, a dynamometer, and an actuator that regulates the throttle valve. In this system, the engine torque is controlled by regulating the position of the throttle valve that is connected to the actuator by a wire. Detected variables are the dynamometer torque and speed, and the actuator position. The engine controller is composed of 12-bit AID , D/A converters and a DSP(TMS320C25) .B. Engine Test MethodThe engine is tested for its performance on each driving mode shown in Table 1. The Engine speed or torque is maintained to the predetermined pattern, while the exhaust gas and fuel cost are measured. The engine performance is evaluated based on the result of measurements. Fig.2 shows the block diagram of the control system of the driving mode 1 shown in Table 1. The engine torque can be detected directly using by the indicated mean effective pressure in theory. However, in practice, it is difficult to detect the engine torque directly because of its structure. In the conventional engine testing, the dynamometer torque is applied as a feedback variable instead of the engine torque as shown in Fig.2. The engine torque control system is affected by the acceleration torque of the dynamometer in a transient condition. As a result, The performance of the engine torque control system is deteriorated. We apply an engine torque observer to eliminate from interference of dynamometer speed control system in the engine torque control.Ill. Decoupling Control MethodA. Engine Torque Estimation MethodThe engine tester is equivalent to a two-mass model of a dynamometer and an engine. We attempted to estimate the engine torque by the use of a reduced order observer. The state-space representation for a two-mass-model shown in Fig.3 is as follows, where the viscosity term is neglected. The estimated variables are the engine torque, the engine speed, and the shaft tor