System and method for calculating vehicle speed and controlling a continuously variable transmission
AssigneeGM Global Technology Operations LLC
InventorCrystal J. Nassouri
Life of this patent
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Abstract
A system and method for controlling a vehicle having a continuously variable transmission (CVT) comprises a control system having at least one controller, an accelerometer and one or more sensors in communication with the at least one controller to monitor and detect a change in an operational state of the vehicle. The control system determines a vehicle acceleration rate with the accelerometer in response to the change in the operational state of the vehicle. An adjusted vehicle speed is computed based, at least in part, on the vehicle acceleration rate. A variator speed ratio is generated based upon the adjusted vehicle speed and transmitted to the variator assembly of the CVT.
Claims17
A method for controlling a vehicle having a continuously variable transmission (CVT) including a variator assembly comprising:
- monitoring an operational state of the vehicle with a control system having at least one controller, an accelerometer and one or more sensors in communication with the at least one controller;
- determining a vehicle acceleration rate with the accelerometer;
- determining when the vehicle encounters an event causing a change in the operational state of the vehicle with the accelerometer and the one or more sensors;
- computing an adjusted vehicle speed, based, at least in part, on the vehicle acceleration rate in response to the event causing the change in the operational state of the vehicle, wherein the step of computing the adjusted vehicle speed further comprises:
- detecting a grade acceleration signal with the accelerometer,
- determining an adjusted vehicle acceleration rate by computing a difference between the vehicle acceleration rate and the grade acceleration signal, and
- computing the adjusted vehicle speed during the change in the operational state of the vehicle by numerically integrating the adjusted vehicle acceleration;
- generating a variator speed ratio based upon the adjusted vehicle speed;
- and
- transmitting the variator speed ratio in response to the change in the operational state of the vehicle to the variator assembly.
A vehicle comprising:
- an internal combustion engine;
- a continuously variable transmission (CVT) comprising:
- an input member;
- an output member;
- a variator assembly including a first pulley and a second pulley, the first and second pulleys rotatably coupled by a flexible continuous rotatable device, wherein the first pulley is rotatably coupled to an input member and the second pulley is rotatably coupled to an output member;
- and
- a control system having at least one controller, an accelerometer and one or more sensors in communication with the at least one controller, the control system including an instruction set, the instruction set executable to:
- monitor an operational state of the vehicle,
- detect a vehicle acceleration rate with the accelerometer in communication with the control system,
- detect an event causing a change in the operational state of the vehicle,
- compute an adjusted vehicle speed, based, at least in part, on the vehicle acceleration rate in response to the event causing the change in the operational state of the vehicle, wherein the computation of the adjusted vehicle speed further comprises:
- detecting a grade acceleration signal with the accelerometer,
- determining an adjusted vehicle acceleration rate by computing a difference between the vehicle acceleration rate and the grade acceleration signal, and
- computing the adjusted vehicle speed during the change in the operational state of the vehicle by numerically integrating the adjusted vehicle acceleration,
- generate a variator speed ratio based upon the adjusted vehicle speed, and
- transmit the variator speed ratio in response to the event change in the operational state of the vehicle to the variator assembly.
A method for controlling a vehicle having a continuously variable transmission (CVT) including a variator assembly comprising:
- monitoring an operational state of the vehicle with a control system having at least one controller, an accelerometer and one or more sensors in communication with the at least one controller;
- detecting an event causing a change in the operational state of the vehicle with the accelerometer and one or more sensors;
- determining a vehicle acceleration rate and a grade acceleration signal with the accelerometer;
- maintaining the grade acceleration signal at a constant value during the change in the operational state of the vehicle;
- determining an adjusted vehicle acceleration rate by computing a difference between the vehicle acceleration rate and the grade acceleration signal;
- computing an adjusted vehicle speed during the change in the operational state of the vehicle by numerically integrating the adjusted vehicle acceleration;
- generating a variator speed ratio based upon the adjusted vehicle speed;
- and
- transmitting the variator speed ratio in response to the change in the operational state of the vehicle to the variator assembly.
Dependencies are inferred from the claim text.