Abstract: A system and method to control the coolant temperature of two independent cooling loops of a fuel cell vehicle by adjusting system pump speed, fan speed and radiator bypass valve position. Multiple feedback controllers coordinated by robust flip-flop logic are used, to minimize energy consumption and provide optimal control system performance even in the case of substantially different plant responses with respect to fan speed and valve position plant inputs. The system also includes a feed forward disturbance compensator, which reacts immediately to change in net power and vehicle speed disturbance variables, thereby reducing the variance of the temperature control error. Additionally, a feedback controller preset strategy is used to compensate for distinctive plant nonlinear effects such as bypass valve dead-zone and air-conditioning system's request for abrupt change of fan speed.

Abstract: Several methods are disclosed for application in a vehicle comprising an engine, an electrical machine coupled to provide supplemental torque to a torque provided by the engine, a transmission having an input coupled to receive torque provided by the engine, and at least one wheel shaft driven by an output of the transmission, the wheel shaft having a driven end and an end coupled to a respective wheel of the motor vehicle. In one embodiment, a method for suppressing driveline oscillations comprises: for at least one wheel shaft, sensing a difference in rotational speed between the driven end of the wheel shaft and the wheel shaft's respective wheel, and generating a torque command for the electrical machine to supply a torque which is a function of the difference.

Abstract: A method for reducing transmission clutch engagement pressure during conditions when clutch hydraulic fluid is relatively more viscous. A clutch engagement pressure control signal is shaped by a system that has an addition branch (42) for shaping the control signal as the control signal is rising, a subtraction branch (44) for shaping the control signal as the control signal is falling, and a summing junction (46) for algebraically summing the signal outputs of the addition and the subtraction branches.

Abstract: Method, for use in a vehicle including a four wheel steering system and an electronic control unit having memory, of controlling the four wheel steering system while at least one of the wheels is under a torque load such that the vehicle behaves like a front wheel steering vehicle under no torque load, or a four wheel steering vehicle under no torque load. The method includes determining at least one control gain for the four wheel steering system so that the torque loaded vehicle behaves like a front wheel steering vehicle under no torque load, and controlling the four wheel steering system according to the control gain, thereby improving directional stability of the vehicle travelling on a slippery road surface. Apparatus is provided for carrying out the method.

Abstract: A vehicle traction controller controls vehicle traction and directional stability by determining the rotational velocity of the vehicle. The rotational velocity of the vehicle is measured and compared to a predefined range. If the rotational velocity is outside of the predefined range, then a wheel torque value, which is indicative of a braking force to be applied independently of driver initated braking, is generated for each wheel which is on a side of the vehicle as determined by the rotational velocity. The wheel torque value is compared to a range of values, which is based on road surface friction, and altered if the wheel torque value is outside of the range of values. Wheel spin and skid control is employed to reduce wheel spin and skid.