Abstract:
A vehicle includes an engine, torque converter assembly, and transmission. The torque converter assembly includes a torque converter clutch (TCC). The transmission is connected to the engine via the torque converter assembly, and includes rotating and braking clutches, a pump, and a valve body assembly (VBA). The VBA includes Micro Electro Mechanical Systems (MEMS) pressure sensors and high-flow, hybrid MEMS flow control valves. Each MEMS pressure sensor and each MEMS control valve is in fluid communication with a corresponding one of the TCC, the rotating, and the braking clutches. The VBA includes first and second low-flow, fully MEMS valves which control line pressure to the VBA and fluid pressure to the TCC, respectively. The VBA delivers fluid pressure to the clutches, alone or in different combinations, to establish at least six different forward drive states of the transmission.
Abstract:
A method of modeling initial temperatures of a dry DCT includes reactivating a controller after a time lapse between first and second clock times representing an offline period. The last known temperatures of a first component and a second component are read and a first temperature difference therebetween is calculated. The method calculates a stop time and a start time on a predefined exponential function from the calculated temperature difference. A first conductive heat transfer between the first and second components is calculated by integrating the predefined exponential function between the stop time and the start time. Based upon the calculated first conductive heat transfer, a first conductive temperature change between the first and second components is calculated. A starting temperature of the first component is calculated from first conductive temperature change, and a control action on the dry DCT is executed based upon the calculated starting temperature.
Abstract:
A vehicle includes an engine, torque converter assembly, and transmission. The torque converter assembly includes a torque converter clutch (TCC). The transmission is connected to the engine via the torque converter assembly, and includes rotating and braking clutches, a pump, and a valve body assembly (VBA). The VBA includes Micro Electro Mechanical Systems (MEMS) pressure sensors and high-flow, hybrid MEMS flow control valves. Each MEMS pressure sensor and each MEMS control valve is in fluid communication with a corresponding one of the TCC, the rotating, and the braking clutches. The VBA includes first and second low-flow, fully MEMS valves which control line pressure to the VBA and fluid pressure to the TCC, respectively. The VBA delivers fluid pressure to the clutches, alone or in different combinations, to establish at least six different forward drive states of the transmission.
Abstract:
A method of controlling a Micro-Electro-Mechanical System (MEMS) valve includes defining a desired pressure output for the MEMS valve. The desired pressure output is related to a control reference value. The control reference value relates an output pressure of the MEMS valve to a measurable characteristic of the MEMS valve. The measurable characteristic may include a resistance, an electrical power, or an electrical current of the MEMS valve. The control reference value is converted to an initial Pulse Width Modulated (PWM) signal that is applied to the MEMS valve. The initial PWM signal may be adjusted to define an adjusted PWM signal based upon a difference between an actual value of the measurable characteristic at the initial PWM signal and the control reference value, until the actual value of the measurable characteristic at the adjusted PWM signal is within a pre-defined range of the control reference value.