Driving force control system for a vehicle

• US 6,090,011 A
• Filed: 04/29/1998
• Issued: 07/18/2000
• Est. Priority Date: 09/16/1992
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Ozaki, Naoyuki, Kimura, Hiroshi, Minowa, Toshimichi, Shiraishi, Takashi, Ishii, Junich
• Primary Examiner(s): Ta, Khoi Q.
• Application Number:
  US09/069,184
• Time in Patent Office: 811 Days
• Field of Search: 477/107, 477/109, 477/110, 477/100
• US Class Current: 477/107
• CPC Class Codes: B60W 10/04 including control of propulsion units
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/11 Stepped gearings
• CPC Class Codes: B60W 10/115 with planetary gears
• CPC Class Codes: B60W 2050/0011 Proportional Integral Differential [PID] controller
• CPC Class Codes: B60W 2050/0022 Gains, weighting coefficients or weighting functions
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/0652 Speed change rate
• CPC Class Codes: B60W 2510/0661 Torque change rate
• CPC Class Codes: B60W 2510/0695 Inertia
• CPC Class Codes: B60W 2510/1005 Transmission ratio engaged
• CPC Class Codes: B60W 2510/102 Input speed change rate
• CPC Class Codes: B60W 2510/1025 Input torque
• CPC Class Codes: B60W 2510/1045 Output speed change rate
• CPC Class Codes: B60W 2510/105 Output torque
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2710/0605 Throttle position
• CPC Class Codes: B60W 2710/0622 Air-fuel ratio
• CPC Class Codes: B60W 2710/0666 Engine torque
• CPC Class Codes: B60W 2710/105 : Output torque
• CPC Class Codes: B60W 30/1819 : Propulsion control with control means using analogue circuits, relays or mechanical links
• CPC Class Codes: B60W 30/19 : Improvement of gear change, e.g. by synchronisation or smoothing gear shift
• CPC Class Codes: F16H 2059/082 : with different modes
• CPC Class Codes: F16H 2059/147 : Transmission input torque, e.g. measured or estimated engine torque
• CPC Class Codes: F16H 2059/148 : Transmission output torque, e.g. measured or estimated torque at output drive shaft
• CPC Class Codes: F16H 2059/363 : Rate of change of input shaft speed, e.g. of engine or motor shaft
• CPC Class Codes: F16H 2059/366 : Engine or motor speed
• CPC Class Codes: F16H 2059/385 : Turbine speed
• CPC Class Codes: F16H 2059/405 : Rate of change of output shaft speed or vehicle speed
• CPC Class Codes: F16H 2059/425 : Rate of change of input or turbine shaft speed
• CPC Class Codes: F16H 2059/467 : of torque converter
• CPC Class Codes: F16H 2059/6807 : Status of gear-change operation, e.g. clutch fully engaged
• CPC Class Codes: F16H 2061/0015 : Transmission control for optimising fuel consumptions
• CPC Class Codes: F16H 2061/0087 : Adaptive control, e.g. the control parameters adapted by learning
• CPC Class Codes: F16H 2061/0096 : using a parameter map
• CPC Class Codes: F16H 59/14 : Inputs being a function of torque or torque demand
• CPC Class Codes: F16H 59/141 : of rate of change of torque or torque demand
• CPC Class Codes: F16H 59/16 : Dynamometric measurement of torque
• CPC Class Codes: F16H 59/24 : dependent on the throttle opening
• CPC Class Codes: F16H 59/36 : Inputs being a function of speed
• CPC Class Codes: F16H 59/48 : Inputs being a function of acceleration
• CPC Class Codes: F16H 59/70 : dependent on the ratio established
• CPC Class Codes: F16H 61/0021 : Generation or control of line pressure
• CPC Class Codes: F16H 61/0437 : by using electrical signals F16H61/0403 and F16H61/061 take precedence
• CPC Class Codes: F16H 61/061 : using electric control means
• CPC Class Codes: F16H 61/08 : Timing control
• CPC Class Codes: F16H 63/502 : for smoothing gear shifts

Abstract

A controller (100 in FIG. 1) for relieving a gear shift shock in a vehicle, comprising an input torque calculation portion (131) which calculates the input torque (T_t) of the stepped automatic transmission mechanism of the vehicle from engine r.p.m. (N_e) and turbine r.p.m. (N_e), a shift start recognition portion (134) which recognizes the real mechanical shift start timing of the stepped automatic transmission mechanism in accordance with the change of the input torque (T_t), a line-pressure correction magnitude calculation portion (142) which calculates a line-pressure correction magnitude (ΔPL) during the gear shift operation of the stepped automatic transmission mechanism when the shift start has been recognized, a standard line pressure calculation portion (143) which calculates a standard line pressure (PL), and a command line pressure calculation portion (144) which adds the line-pressure correction magnitude (ΔPL) to the standard line pressure (PL) and which delivers the resulting sum to a valve (52) for controlling the oil pressure of the hydraulic circuit of the stepped automatic transmission mechanism.

Claims

1. A control device for a vehicle having an engine and an automatic transmission including a transmission mechanism provided at an output shaft of the engine, said control device comprising:

a shift condition recognizing unit for recognizing whether or not said automatic transmission is undergoing shifting;

an air-fuel-ratio calculating unit for calculating an air-fuel-ratio of said engine; and

a driving axle torque control unit for changing said air-fuel-ratio under shifting calculated by said calculating unit during a time period based on a timing recognized by said shift condition recognizing unit so as to control a driving axle torque of a driving axle connected to said transmission mechanism according to said air-fuel-ratio under shifting.

2. The control device according to claim 1, further comprising:

engine speed detection means for detecting a rotation speed of the output shaft of said engine;

turbine speed detection means for detecting a rotation speed of a turbine of a torque converter provided between said engine and said automatic transmission;

driving axle torque estimation means for estimating an actual driving axle torque of said automatic transmission in accordance with the engine speed detected by said engine speed detection means and the turbine speed detected by said turbine speed detection means;

vehicle speed detection means for detecting a running speed of said vehicle;

accelerator pedal stroke detection means for detecting an accelerator pedal stroke of an accelerator pedal of said vehicle;

target driving torque calculating means for calculating a target driving axle torque which makes a torque of an output torque side of said automatic transmission in accordance with said vehicle speed and said accelerator pedal stroke; and

target engine torque calculating means for obtaining a target engine torque from a deviation between the target driving axle torque calculated by said target driving axle torque calculating means and the actual driving axle torque estimated by said driving axle torque estimation means, wherein;

said air-fuel-ratio calculating unit calculates said air-fuel-ratio in accordance with at least the target engine torque calculated by said target engine torque calculating means.

3. The control device according to claim 2, wherein said engine is controlled in accordance with at least one of said target air-fuel-ratio calculated by said air-fuel-ratio calculating means and said target engine torque calculated by said target engine torque calculating means.

4. A control method for a vehicle having an engine and an automatic transmission including a transmission mechanism provided at an output shaft of the engine, said control device comprising the steps of:

recognizing whether or not said automatic transmission is undergoing shifting;

calculating a target air-fuel-ratio of said engine; and

controlling a target value of air-fuel-ratio under shifting in response to the calculated target air-fuel ratio during a time period when a shifting is recognized, so as to control a driving axle torque of a driving axle connected to said transmission mechanism according to the target value of air-fuel-ratio under shifting.

5. The control method according to claim 4, further comprising the steps of:

detecting an engine rotation speed of the output shaft of said engine;

detecting a turbine rotation speed of a turbine of a torque converter provided between said engine and said automatic transmission;

estimating an actual driving axle torque of said automatic transmission in accordance with the detected engine rotation speed and the detected turbine rotation speed;

detecting a running speed of said vehicle;

detecting an accelerator pedal stroke of an accelerator pedal of said vehicle;

calculating a target driving axle torque which makes a torque of an output torque side of said automatic transmission in accordance with said vehicle speed and said accelerator pedal stroke;

obtaining a target engine torque from a deviation between the calculated target driving axle torque and the estimated actual driving axle torque; and

calculating an air-fuel-ratio of said engine in accordance with at least said target engine torque.

6. The control method according to claim 5, further comprising the step of controlling said engine in accordance with at least one of said calculated air-fuel-ratio and said calculated target engine torque.