Safety system for a motor vehicle

• US 5,987,372 A
• Filed: 06/19/1997
• Issued: 11/16/1999
• Est. Priority Date: 06/21/1996
• Status: Expired due to Term

• Current Assignee: Daimler AG (Mercedes-Benz Group AG)
• Original Assignee: Mercedes-Benz AG (Mercedes-Benz Group AG)
• Inventors: Schenk, Juergen, Wolf, Hans-Christoph
• Primary Examiner(s): LOUIS JACQUES, JACQUES H
• Application Number:
  US08/879,037
• Time in Patent Office: 880 Days
• Field of Search: 701/101, 701/102, 701/110, 701/69, 180/197, 180/65.1, 180/65.2, 180/65.3, 180/65.4, 180/65.5, 180/165, 180/282, 60/431, 60/434, 60/445, 60/452, 290/14, 290/17, 318/139
• US Class Current: 701/69
• CPC Class Codes: B60K 28/10 responsive to conditions relating to the vehicle
• 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
• CPC Class Codes: B60W 2710/0666 Engine torque
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809

Abstract

The invention relates to a safety system for a motor vehicle having an internal-combustion engine. Independent quantities are used for the engine control and for the monitoring of the engine control. The control of the internal-combustion engine takes place by way of an operating parameter indicative of the operating condition of the internal-combustion engine--such as the engine load. In contrast, the monitoring of the engine control takes place by means of a quantity indicative of vehicle propulsion, such as the vehicle output torque, which is determined on the basis of a rotational wheel speed. The desired values for the engine control and for the monitoring are determined from the accelerator pedal position. The detection of the corresponding actual values is based on independent input quantities.

Claims

1. Safety system for a motor vehicle having an internal-combustion engine, comprising:

a sensor for measuring an accelerator pedal position,

means for determining an actual value for at least one operating parameter which is indicative of an operating condition of the internal-combustion engine;

means for determining at least one quantity indicative of vehicle propulsion;

means for determining a desired value for vehicle propulsion and a desired value for the operating parameter indicative of the operating condition of the internal-combustion engine, based on the accelerator pedal position;

means for adjusting the actual value of the operating parameter indicative of the operating condition of the internal-combustion engine to correspond to the determined desired value thereof; and

means for the continuously comparing the actual and desired values for vehicle propulsion, and for recognizing a fault if there is a deviation of the actual value from the desired value.

2. Safety system according to claim 1, wherein a deviation is recognized when a difference between the actual and desired vehicle propulsion values exceeds a preset threshold value for a preset time period.

3. Safety system according to claim 1, wherein, when a fault is recognized, adjustment of the operating parameter indicative of the operating condition of the internal-combustion engine is performed on the basis of the differential value.

4. Safety system according to claim 1, wherein, when a fault is recognized, a signal for reducing the actual vehicle propulsion value is transmitted to an ignition adjustment unit for initiating an ignition intervention.

5. Safety system according to claim 4, wherein, when, despite an ignition intervention, the actual vehicle propulsion value exceeds the desired vehicle propulsion value, a signal for switching off the fuel is transmitted to a fuel distributing device.

6. Safety system according to claim 1, wherein, when a fault is recognized, a fault signal is generated and is indicated to the driver.

7. Safety system according to claim 6, wherein, when a fault is recognized, a fault signal is generated and is indicated to the driver and is stored in a memory.

8. Safety system according to claim 7, further comprising a traction control system, and wherein the rotational wheel speed is detected by the traction control system and is transmitted to the analyzing device.

9. Safety system according to claim 1, wherein

in addition to the accelerator pedal position, an engine load value and a rotational speed are detected on at least one vehicle wheel;

a desired load value and a desired output torque are determined based on the accelerator pedal position, and an actual output torque is determined based on the at least one rotational wheel speed;

the actual load value adjusted to correspond to the desired load value by influencing an operating parameter which influences the engine load; and

the actual output torque and desired output torque are continuously compared, and a fault is recognized if the actual output torque deviates from the desired output torque.

10. A method for controlling operation in a motor vehicle having an internal combustion engine, said method comprising the steps of:

measuring an accelerator pedal position;

determining an actual value for at least one operating parameter which is indicative of an operating condition of the internal combustion engine;

determining an actual value for at least one quantity indicative of vehicle propulsion;

determining a desired value for vehicle propulsion and a desired value for the operating parameter indicative of the operating condition of the internal combustion engine, based on the accelerator pedal position;

adjusting the actual value of the operating parameter indicative of the operating condition of the internal combustion engine to correspond to the determined desired value;

continuously comparing the actual and desired values for vehicle propulsion; and

recognizing a fault if there is a deviation of the actual value from the desired value.