Method of determining a commanded friction brake torque
AssigneeGM Global Technology Operations LLC
InventorsAnthony H. Heap, Jordan Billet
Life of this patent
Estimating the term…
Abstract
A method of determining a commanded friction brake torque is disclosed. The method uses inputs, such as from a gearshift sensor, an accelerator pedal sensor, a brake pedal sensor, and engine torque output sensor, a transmission speed input sensor and a transmission speed output sensor, to determine how much engine braking or regenerative braking is occurring. The method then uses this information combined with the braking command information from the brake pedal sensor to determine the amount of friction braking to apply to the friction brakes.
Claims19
A method of controlling a transmission during closed throttle downshifts comprising:
- determining a transmission kinematic state based on a commanded transmission gear range, a transmission input speed, and a transmission output speed;
- determining a transmission input torque;
- determining a first rotational acceleration of a first portion of the transmission rotationally disposed at a first reference point in the transmission;
- determining a second rotational acceleration of a second portion of the transmission rotationally disposed at a second reference point in the transmission;
- and
- determining a transmission output torque as a sum of a gear ratio of the commanded transmission gear range multiplied by the transmission input torque, a first aggregate inertia multiplied by the first rotational acceleration, and a second aggregate inertia multiplied by the second rotational acceleration, wherein the first and second aggregate inertias are based on the transmission kinematic state.
A method of determining a transmission output torque TOUT for a transmission, comprising:
- determining a transmission kinematic state based on a commanded transmission gear range, a transmission input speed NIN, and a transmission output speed NOUT, wherein the transmission kinematic state is one of a first gear state having a first gear ratio, a second gear state having a second gear ratio lower than the first gear ratio, and an intermediate state during which the transmission transitions from the first gear state to the second gear state;
- determining a transmission input torque TIN;
- determining a first acceleration Ndot1 at a first reference point in the transmission;
- determining a second acceleration Ndot2 at a second reference point in the transmission;
- and
- determining the transmission output torque TOUT as A(TIN)+B(Ndot1)+C(Ndot2), wherein A is a gear ratio of the commanded transmission gear range, and B and C are aggregate inertias based on the transmission kinematic state.
A method of determining a transmission output torque TOUT for a transmission, comprising:
- determining a transmission kinematic state based on a commanded transmission gear range, a transmission input speed NIN, and a transmission output speed NOUT, wherein the transmission kinematic state is one of a first gear state having a first gear ratio, a second gear state having a second gear ratio lower than the first gear ratio, and an intermediate state during which the transmission transitions from the first gear state to the second gear state;
- determining a transmission input torque TIN;
- determining a first acceleration Ndot1 at a first reference point in the transmission;
- determining a second acceleration Ndot2 at a second reference point in the transmission different from the first reference point;
- determining a third acceleration Ndot3 at a third reference point in the transmission different from each of the first and second reference points;
- and
- determining the transmission output torque TOUT as A(TIN)+B(Ndot1)+C(Ndot2)+D(Ndot3), wherein A is a gear ratio of the commanded transmission gear range and B, C and D are aggregate inertias based on the transmission kinematic state.
Dependencies are inferred from the claim text.