Method of reducing the speed of a vehicle having a collision avoidance system

• US 5,889,476 A
• Filed: 12/12/1996
• Issued: 03/30/1999
• Est. Priority Date: 12/14/1995
• Status: Expired due to Fees

• Current Assignee: FEV Motorentechnik GmbH
• Original Assignee: FEV Motorentechnik GmbH
• Inventors: Schmitz, Gunter
• Primary Examiner(s): Lefkowitz, Edward
• Application Number:
  US08/764,753
• Time in Patent Office: 838 Days
• Field of Search: 340/903, 340/904, 340/935, 340/936, 767/909, 180/169, 180/170, 180/167, 180/271, 180/272, 701/301
• US Class Current: 340/903
• CPC Class Codes: B60K 28/10 responsive to conditions relating to the vehicle
• CPC Class Codes: B60K 31/0008 including means for detecting potential obstacles in vehicle path
• CPC Class Codes: B60T 7/22 initiated by contact of vehicle, e.g. bumper, with an external object, e.g. another vehicle , or by means of contactless obstacle detectors mounted on the vehicle
• CPC Class Codes: F01L 13/06 for braking
• CPC Class Codes: F02D 13/04 using engine as brake
• CPC Class Codes: F02D 41/021 Introducing corrections for particular conditions exterior to the engine conjoint control of vehicle sub-units for propelling the vehicle B60W30/18
• CPC Class Codes: Y10S 367/909 Collision avoidance

Abstract

A method of reducing the travelling speed of a vehicle which has a multi-cylinder, piston-type internal-combustion engine, a variably controllable valve drive and a collision avoidance system includes the following steps: continuously determining, by the collision avoidance system, an actual distance between the vehicle and a vehicle ahead and comparing the actual distance with a speed-dependent minimum safe distance; and braking the vehicle by switching over at least one of the engine cylinders to a compressor operation when the actual distance falls below a minimum safe distance.

Claims

1. A method of reducing the travelling speed of a vehicle, comprising the following steps:

(a) providing the vehicle with a multi-cylinder, piston-type internal-combustion engine;

(b) providing the engine with a fully variably control lable valve drive;

(c) providing the vehicle with a collision avoidance system;

(d) continuously determining, by the collision avoidance system, an actual distance between the vehicle and a vehicle ahead and comparing the actual distance with a speed-dependent minimum safe distance;

(e) braking the vehicle by switching over at least one of the engine cylinders to a compressor operation when the actual distance falls below said minimum safe distance; and

(f) controlling said valve drive of said cylinder and controlling the quantity of cylinders operating as a compressor as a function of the speed at which the actual distance is reduced.

2. The method as defined in claim 1, wherein step (a) comprises the step of providing a four-cycle engine and further wherein step (e) comprises the step of switching over to a two-cycle compressor operation.

3. The method as defined in claim 1, further comprising the steps of providing a steplessly variable gear having a transmission ratio for setting the travelling speed of the vehicle and reducing said transmission ratio when said collision avoidance system effects a forced braking.

4. The method as defined in claim 3, wherein the step of reducing said transmission ratio includes the step of limiting a reduction of said transmission ratio by a predetermined maximum rpm of the engine.

5. The method as defined in claim 3, further comprising the step of controlling said steplessly variable gear as a function of the speed at which the actual distance is reduced.

6. The method as defined in claim 1, wherein a control for a forced braking is switched off by the driver by actuating said valve drive.

7. The method as defined in claim 3, wherein a control for a forced braking is switched off by the driver by actuating said steplessly variable gear.

8. A method of reducing the travelling speed of a vehicle, comprising the following steps:

(a) providing the vehicle with a multi-cylinder, piston-type internal-combustion engine;

(b) providing the engine with a fully variably controllable valve drive;

(c) providing the vehicle with a collision avoidance system;

(d) continuously determining, by the collision avoidance system, an actual distance between the vehicle and a vehicle ahead and comparing the actual distance with a speed-dependent minimum safe distance;

(e) providing the vehicle with a steplessly variable gear having a transmission ratio for setting the travelling speed of the vehicle;

(f) forcibly braking the vehicle by the collision avoidance system when the actual distance falls below said minimum safe distance;

(g) controlling said valve drive of said cylinder and controlling the quantity of cylinders operating as a compressor as a function of the speed at which the actual distance is reduced; and

(h) reducing said transmission ratio when said collision avoidance system effects a forced braking.