Abstract: An automatic transmission is disclosed that includes a clutch pressure control module housing having therein: (1) a plurality of solenoid valves, each of the solenoid valves configured to receive an input of the pressurized hydraulic fluid and to provide a variable output pressure of pressurized hydraulic fluid in response to an electric control signal; (2) means for sensing output pressure from each of the solenoid valves of the plurality of solenoid valves; and (3) electronic control means configured to generate electric control signals to one or more of the solenoid valves of the plurality of solenoid valves in response to (i) a clutch pressure command signal or a solenoid pressure command signal, and (ii) a solenoid output pressure signal from the means for sensing output pressure. The solenoid valves provide hydraulic control signals to clutch hydraulic pressure control valves, which in turn provide hydraulic power to clutch actuators.

Abstract: A method is described for controlling a solenoid-operated fluid valve having an output hydraulic pressure that varies in accordance with an input solenoid control current delivered from a drive circuit. A model is provided characterizing the plant dynamics of the solenoid-operated fluid valve and the drive circuit where the model is dependent on at least one operating parameter. The method, during operation, involves measuring the value of the operating parameter and adjusting based on the measured operating parameter value one or more gain constants to be used in a selected control strategy. The model is used in adjusting the gains. Finally, the method involves determining a required solenoid control current according to the control strategy with the now dynamically-adjusted gain constants. The control strategy may be a PI control strategy. The model-based system allows easy migration of the general control strategy to different hardware configurations by developing target system specific data for the model.

Abstract: A vehicle automatic speed change power transmission control includes a control arrangement with overshoot/undershoot protection logic. The control is used with an electro-hydraulic pressure control module featuring a linear solenoid, and which supplies a hydraulically-actuated clutch configured to effect gear changes. The overshoot/undershoot protection logic is configured to detect when a commanded increase/decrease clutch pressure satisfies a clutch pressure threshold and to then activate the protection logic. Once the protection logic is activated, large command pressures increases/decreases are implemented in a series of stages having variable gains. The first stage has an aggressive gain and achieves 50-80% of the commanded clutch pressure. The second stage has a reduced gain and achieves 90% of the commanded clutch pressure. The third stage has a still further reduced gain and achieves about 100% of the commanded clutch pressure.

Abstract: A transmission clutch pressure control apparatus is suitable for a configuration that includes a pilot valve and a pressure regulating valve working in tandem. The pilot valve produces a pilot pressure that varies in accordance with a pilot valve drive signal. The pressure regulating valve provides fluid to a clutch at an output clutch pressure that is in turn variable based on the pilot pressure. The apparatus includes a pilot pressure sensor in fluid communication with the pilot valve output and generates a pilot pressure signal. The apparatus also includes a control arrangement having a pilot valve pressure estimation block configured to produce a pilot pressure command in response to a clutch pressure command. The estimation block is configured to reflect the relationship between the clutch pressure and the pilot pressure. The control arrangement also includes a summer that produces an error signal based on the difference between the commanded and sensed pilot pressure.

Abstract: A camshaft phaser system includes an oil control spool valve having two opposing springs to center the spool at a rest position to lock the phaser rotor by blocking supply/vent to both the C1 and C2 chambers, obviating a conventional locking pin mechanism. A double-acting solenoid actuator moves the spool to first and second positions, supplying or venting C1 and C2, respectively. The rotor may be locked hydraulically at any position between full advance and full retard. A system for monitoring the rotational positions of the crankshaft and camshaft includes magnets disposed on opposite sides of the shaft axis. A magnetic sensing element senses the rotational direction of the magnetic field for each position of the shaft. An engine control module uses the position signal and an algorithm to lock the rotor at a desired position.

Abstract: A transmission control arrangement controls the generation of a required solenoid control current that is provided to an electro-hydraulic pressure control module to ultimately control clutch pressure. The module includes a linear solenoid, which has an up direction pressure-current (P-I) data table and a down direction pressure-current (P-I) data table associated therewith. For large pressure increase change requests the up P-I table is used. For large pressure decrease change requests the down P-I table is used. An interpolation process uses current values taken from both the up and down P-I data tables for pressure change requests that are neither large increases nor large decreases. The control arrangement also includes a variable gain feature that changes the gain in dependence on the gear state of the transmission.

Abstract: A camshaft phaser system includes an oil control spool valve having two opposing springs to center the spool at a rest position to lock the phaser rotor by blocking supply/vent to both the C1 and C2 chambers, obviating a conventional locking pin mechanism. A double-acting solenoid actuator moves the spool to first and second positions, supplying or venting C1 and C2, respectively. The rotor may be locked hydraulically at any position between full advance and full retard. A system for monitoring the rotational positions of the crankshaft and camshaft includes magnets disposed on opposite sides of the shaft axis. A magnetic sensing element senses the rotational direction of the magnetic field for each position of the shaft. An engine control module uses the position signal and an algorithm to lock the rotor at a desired position.

Abstract: A pressure holding apparatus incorporates a hydraulic pressure system having an engine-driven pressure source, a pressure holding valve, and a torque-transmitting mechanism. The torque-transmitting mechanism is selectively engaged and disengaged by fluid pressure from the engine-driven pressure source during normal powertrain operation. The torque-transmitting mechanism apply chamber is pressurized with the oil by the pressure holding valve when the engine operation is discontinued.

Abstract: A pressure holding apparatus incorporates a hydraulic pressure system having an engine-driven pressure source, a pressure holding valve, and a torque-transmitting mechanism. The torque-transmitting mechanism is selectively engaged and disengaged by fluid pressure from the engine-driven pressure source during normal powertrain operation. The torque-transmitting mechanism apply chamber is pressurized with the oil by the pressure holding valve when the engine operation is discontinued.