Output control apparatus for vehicle

• US 5,255,192 A
• Filed: 05/16/1991
• Issued: 10/19/1993
• Est. Priority Date: 05/18/1990
• Status: Expired due to Term

• Current Assignee: Mitsubishi Jidosha Kogyo Kabushiki Kaisha
• Original Assignee: Mitsubishi Jidosha Kogyo Kabushiki Kaisha
• Inventors: Yamada, Kiichi, Ito, Masayoshi, Narita, Tomohiro, Otake, Katsunori, Miyata, Yasunobu, Hashiguchi, Masayuki
• Primary Examiner(s): Chin, Gary
• Application Number:
  US07/701,507
• Time in Patent Office: 887 Days
• Field of Search: 364/426.02, 364/426.03, 180/197, 303/97, 303/99, 303/103, 303/105
• US Class Current: 701/90
• CPC Class Codes: B60K 28/16 responsive to, or preventing, skidding of wheels brake control systems for vehicle drive stability B60T8/1755; arrangements responsive to a speed condition for adjusting wheel braking force B60T8/32; control of vehicle driving stability otherwise than by controlling the propulsion unit only B60W30/02; preventing wheel slippage by reducing power in rail vehicles B61C15/00

Abstract

An output control apparatus for a vehicle includes a torque reduction device for reducing driving torque of an engine independent of manipulation by the driver and a vehicle speed detection device for detecting a vehicle speed. It further includes a reference driving torque setting device for setting a reference driving torque according to the vehicle speed detected by the vehicle speed detection device. A reference torque setting device is further included for setting a reference driving torque according to a slip amount of the driving wheels. A target driving torque setting device is further included for setting a target driving torque from the reference driving torque set by the reference torque setting device according to a peripheral speed of the driving wheels. A torque control unit is also included for controlling operation of the torque reduction device so that the driving torque is that of the target driving torque set by the target driving torque setting device. Finally, a turning correction device is included for correcting the target driving torque according to the steering angle, to adequately control the driving force of the vehicle during turning, separately from that of straightforward traveling, thereby enabling safe and smooth traveling of the vehicle.

Claims

1. An output control apparatus for a vehicle comprising:

torque adjusting means for adjusting driving torque independent of manipulation by a driver of the vehicle;

driven wheel speed detection means for detecting rotational speed of driven wheels of the vehicle;

reference torque setting means for setting a reference driving torque according to said driven wheel speed detected by said driven wheel speed detection means;

driving wheel speed detection means for detecting rotational speed of driving wheels of the vehicle;

slip detection means for detecting a slip amount of the driving wheels according to said driving wheel speed detected by said driving wheel speed detection means and said driven wheel speed detected by said driven wheel speed detection means;

steering angle detection means for detecting a steering angle of the vehicle;

steering angle-dependent lateral acceleration calculation means for calculating a steering angle-dependent lateral acceleration estimated to generate in the vehicle according to said steering angle detected by said steering angle detection means;

turning correction means for correcting said slip amount so that said slip amount detected by said slip detection means increases in association with an increase in said steering angle-dependent lateral acceleration calculated by said steering angle-dependent lateral acceleration calculation means;

correction torque setting means for setting a correction torque according to said slip amount corrected by said turning correction means;

driving torque correction means for correcting said reference driving torque set by said reference driving torque setting means by said correction torque to calculate a target driving torque; and

torque control means for controlling said torque adjusting means so that an actual driving torque is equal to said target driving torque calculated by said driving torque correction means.

2. The output control apparatus of claim 1 wherein said turning correction means adds a cornering drag, increasing as said steering angle detected by said steering angle detection means increases, to said target driving torque.

3. The output control apparatus of claim 1 wherein said slip detection means includes, target driving wheel speed setting means for setting a target driving wheel speed according to said driven wheel speed detected by said driven wheel speed detection means,

a difference between said driving wheel speed detected by said driving wheel speed detection means and said target driving wheel speed set by said target driving wheel speed setting means being said slip amount of the driving wheels.

4. The output control apparatus of claim 3 wherein said turning correction means corrects said target driving wheel speed so that said target driving wheel speed decreases as said steering angle-dependent lateral acceleration calculated by said steering angle-dependent lateral acceleration calculation means increases.

5. The output control apparatus of claim 1, wherein said steering angle-dependent lateral acceleration calculation means calculates said steering angle-dependent lateral acceleration according to a vehicle speed, said steering angle, and a stability factor.

6. The output control apparatus of claim 1 wherein said turning correction means includes, driven wheel speed-dependent lateral acceleration calculation means for determining a lateral acceleration of the vehicle according to speeds of the right and left driven wheels, and lateral acceleration select means for correcting said slip amount using said driven wheel speed-dependent lateral acceleration before beginning detection of said steering angle by the steering angle sensor of the steering angle detection means, and for correcting said slip amount using said steering angle-dependent lateral acceleration after beginning detection of said steering angle.

7. The output control apparatus of claim 6, wherein said steering angle sensor begins detection of said steering angle according to a steering angle neutral position after said steering angle neutral position is confirmed.

8. The output control apparatus of claim 6 wherein said lateral acceleration select means corrects said slip amount using said driven wheel speed-dependent lateral acceleration when detection of said steering angle is impossible by said steering angle sensor.

9. The output control apparatus of claim 6 wherein said turning correction means sets a correction value to said slip amount to smaller value when output of said lateral acceleration select means is said steering angle-dependent lateral acceleration, than when the output is said driven wheel speed-dependent lateral acceleration.

10. An output control method for a vehicle comprising the steps of:

(a) adjusting driving torque independent of manipulation by a driver of the vehicle;

(b) detecting rotational speed of driven wheels of the vehicle;

(c) setting a reference driving torque according to said driven wheel speed detected in said step (b);

(d) detecting rotational speed of driving wheels of the vehicle;

(e) detecting a slip amount of the driving wheels according to said driving wheel speed detected in said step (d) and said driven wheel speed detected in said step (b);

(f) detecting a steering angle of the vehicle;

(g) calculating a steering angle-dependent lateral acceleration estimated to generate in the vehicle according to said steering angle detected in said step (f);

(h) correcting the slip amount so that said slip amount detected in said step (e) increases in association with an increase in said steering angle-dependent lateral acceleration calculated in said step (g);

(i) setting a correction torque according to said slip amount corrected in said step (h);

(j) correcting said reference driving torque set in said step (c) by said correction torque of step (i) to calculate a target driving torque; and

(k) controlling and adjusting of step (a) so that an actual driving torque is equal to said target driving torque calculated in said step (j).

11. The output control method of claim 10 wherein said step (h) includes adding a cornering drag, increasing as said steering angle detected in said step (f) increases, to the target driving torque.

12. The output control method of claim 10 wherein said step (e) includes

(i) setting a target driving wheel speed according to said driven wheel detected in said step (b),

wherein a difference between said driving wheel speed detected in said step (d) and said target driving wheel speed set in step (e) (i) is the said slip amount of the driving wheels.

13. The output control method of claim 12 wherein said step (h) includes correcting the target driving wheel speed so that the target driving wheel speed decreases as said steering angle-dependent lateral acceleration calculated in said step (g) increases.

14. The output control method of claim 10 wherein said step (h) includes,

(i) determining a driven wheel speed-dependent lateral acceleration of the vehicle according to speeds of the right and left driven wheels,

(ii) correcting said slip amount using said driven wheel speed-dependent lateral acceleration before beginning detection of said steering angle of said step (f), and

(iii) correcting said slip amount using said steering angle-dependent lateral acceleration after beginning detection of said steering angle in said step (f).

15. The output control method of claim 14 wherein said slip amount is corrected in said step (h) (iii) using said driven wheel speed-dependent lateral acceleration when detection of said steering angle is impossible in said step (f).

16. The output control method of claim 14 wherein a correction value to said slip amount is set, in said step (h), to a smaller value when said steering angle-dependent lateral acceleration is used, than when said driven wheel speed-dependent lateral acceleration is used.

17. The output control method of claim 10, wherein said steering angle-dependent lateral acceleration is calculated in said step (g) according to a vehicle speed, said steering angle, and a stability factor.

18. The output control method of claim 14, wherein said steering angle is initially detected in step (g) according to a steering angle neutral position after the steering angle neutral position is confirmed.