US 5,439,428 AGranted

Method and apparatus for robust automatic clutch control with pid regulation

AssigneeEaton Corporation

InventorJames Slicker

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Abstract

An automatic clutch controller for a vehicle that reduces the oscillatory response to clutch engagement. The automatic clutch controller receives inputs from an engine speed sensor and a transmission input speed sensor and develops a clutch actuation signal controlling a clutch actuator from disengaged to fully engaged. The clutch engagement signal at least partially engages the friction clutch in a manner to cause the measured transmission input speed to asymptotically approach engine speed employing an approximate inverse model of this oscillatory response. The automatic clutch controller preferably includes a PID function and a differential engine speed function, which together adaptively adjust clutch engagement corresponding to vehicle loading. The automatic clutch controller includes a PID regulator responsive to the difference of engine speed and transmission input speed, a prefilter operating on the resulting PID signal, and a compensator constructed to reduce the need for detailed particularization for individual vehicles or vehicle models by reducing the system closed loop sensitivity to vehicle parameter variations.

Claims9

Dependent claims

In a combination including a source of motive power controlled by a throttle, a friction clutch having an input shaft connected to the source of motive power and an output shaft, and at least one inertially-loaded traction wheel connected to the output shaft of the friction clutch having a torsional compliance exhibiting an oscillatory response to torque inputs, an automatic clutch controller comprising:

an engine speed sensor connected to the source of motive power for generating an engine speed signal corresponding to the rotational speed of the source of motive power;
a transmission input speed sensor connected to the output shaft of the friction clutch for generating a transmission input speed signal corresponding to the rotational speed of the output shaft of the friction clutch;
a clutch actuator connected to the friction clutch for controlling engagement of the friction clutch from disengaged to fully engaged according to a clutch engagement signal;
and
a controller connected to said engine speed sensor, said transmission input speed sensor and said clutch actuator including
a PID regulator coupled to the engine speed sensor and the input speed sensor for generating a regulated output,
a prefilter connected to said PID regulator for generating a filtered PID signal,
a first algebraic summer connected to said transmission input speed sensor and said prefilter generating a first algebraic sum signal corresponding to the difference between (1) said filtered PID signal and (2) said transmission input speed signal, and
a compensator connected to said first algebraic summer for decreasing closed loop sensitivity and for generating said clutch engagement signal for supply to said clutch actuator for engaging the friction clutch in a manner causing said transmission input speed to asymptotically approach said engine speed.

6 more elements

In a combination including an engine controlled by a throttle, a transmission having an input shaft, a traction wheel driven by the transmission, and a friction clutch connected between the engine and the transmission input shaft having a torsional compliance exhibiting an oscillatory response to torque inputs, and an automatic clutch control apparatus comprising sensors for the throttle position, engine speed, and input shaft speed, a clutch actuator connected to the friction clutch for controlling engagement of the friction clutch from disengaged to fully engaged positions according to a clutch engagement signal;

a method of generating a clutch engagement signal comprising the steps of:
determining the engine speed and the input shaft speed;
producing a proportional-integral-differential (PID) value from the engine speed and the input shaft speed;
filtering the PID value;
generating an error by subtracting the input shaft speed from the filtered PID value;
and
compensating the error to produce a compensated output value by maintaining reduced sensitivity to variations in the response to torque inputs of the traction wheel to generate said clutch engagement signal to thereby engage the friction clutch in a manner causing said transmission input speed signal to asymptotically approach said engine speed signal.

4 more elements

Dependencies are inferred from the claim text.