Human driving behavior consists of target (path and velocity) planning and actual vehicle control based on the target. A human driver can control a vehicle. The person is not an electronic controller and has no vehicle control program before driving skill being trained. Once a certain level skill learned, driving target planning and related apparatus operation are done unconsciously like running. Hand tools are considered as extended hand. Those tools are operated without being feel to control movement of those. A vehicle may be felt as further extending human body in driving. A driver thinks destination but does not imagine accelerator or brake operation schedule. Vehicle response property learned affects the target planning and driving operation. A target plant can be described with operation gain and response in a control system. Torque response of a gasoline engine is depending on the plenum chamber volume and cylinder displacement ratio if air fuel ratio is set at stoichiometric. That of diesel engine is depending on only fuel injection delay if air is supplied sufficiently. However, turbo-charging process takes a few second to boost air supply to combustion chambers and the delay time can be calculated with a transfer function. Torque response of an electric motor, only depending on current rise, is quicker than that of ICEs. And the operation gain is rather linear than ICEs. A brake system has smaller response time comparing with an ICE and more liner operation gain to applied pedal force. A closed loop system included a human controller, i.e. a driver, to be constructed and a powertrain. And stability and target error are to be analyzed with transfer functions of a driver and a powertrain. From published papers, control performance deterioration is expected and the deterioration is to be quantitively shown. Desired X-by-wired powertrain property is to be mentioned.
Dr. Eng. Kazuhide Togai, Osaka Sangyo University, JAPAN