Process and system for controlling the longitudinal dynamics of a motor vehicle

• US 6,246,945 B1
• Filed: 10/12/1999
• Issued: 06/12/2001
• Est. Priority Date: 08/10/1996
• Status: Expired due to Term

• Current Assignee: Bayerische Motoren Werke AG
• Original Assignee: Daimler Chrysler Company LLC (Stellantis NV)
• Inventors: Fritz, Hans, Gehring, Ottmar
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): To, Tuan C
• Application Number:
  US09/415,055
• Time in Patent Office: 609 Days
• Field of Search: 701/70, 701/71, 701/79, 702/148, 180/141, 303/140, 303/112, 303/157
• US Class Current: 701/70
• CPC Class Codes: B60K 31/047 the memory being digital
• CPC Class Codes: B60T 8/172 Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters B60T8/17551 takes precedence
• CPC Class Codes: B60T 8/175 Brake regulation specially adapted to prevent excessive wheel spin during vehicle acceleration, e.g. for traction control safety devices for propulsion unit control responsive to, or preventing, skidding of wheels B60K28/16
• CPC Class Codes: B60T 8/17616 Microprocessor-based systems
• CPC Class Codes: B60W 10/04 including control of propulsion units
• CPC Class Codes: B60W 10/18 including control of braking systems
• CPC Class Codes: B60W 2050/0031 Mathematical model of the vehicle
• CPC Class Codes: B60W 2510/1005 Transmission ratio engaged
• CPC Class Codes: B60W 2520/105 Longitudinal acceleration
• CPC Class Codes: B60W 2530/10 Weight
• CPC Class Codes: B60W 2530/16 Driving resistance
• CPC Class Codes: B60W 2552/15 Road slope, i.e. the inclination of a road segment in the longitudinal direction
• CPC Class Codes: B60W 2710/1011 Input shaft speed, e.g. turbine speed
• CPC Class Codes: B60W 2710/1022 Input torque
• CPC Class Codes: B60W 2720/106 Longitudinal acceleration
• CPC Class Codes: B60W 30/1819 Propulsion control with control means using analogue circuits, relays or mechanical links
• CPC Class Codes: B60W 30/188 Controlling power parameters of the driveline, e.g. determining the required power
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

In a process and a system for controlling the longitudinal dynamics of a motor vehicle, a drive train actuating signal is determined from actual vehicle condition data, controller-internal desired longitudinal velocity values, and desired longitudinal acceleration values determined by means of fed input data concerning the desired longitudinal acceleration and the actual driving condition. According to the invention, as a function of the controller-internal desired longitudinal velocity values and desired longitudinal acceleration values as well as of actual driving condition data, by means of an inverse characteristic vehicle longitudinal dynamics diagram, a desired drive train actuating signal is determined and the drive train actuating signal is determined therefrom.

Claims

1. Process for controlling the longitudinal dynamics of a motor vehicle, comprising:

determining controller-internal desired longitudinal velocity values and desired longitudinal acceleration values based on fed input data concerning desired longitudinal acceleration and concerning actual driving conditions, and

determining a drive train actuating signal based on actual driving condition data as well as on the controller-internal desired longitudinal velocity values and desired longitudinal acceleration values;

wherein

a desired drive train actuating signal is determined as a function of the controller-internal desired longitudinal velocity values and the desired longitudinal acceleration values, and as a function of actual driving condition data, using an inverse characteristic vehicle longitudinal dynamics diagram; and

a drive train actuating signal is determined based on the desired drive train actuating signal.

2. Process according to claim 1, wherein the actual driving condition data used for the characteristic-diagram-based determination of the desired drive train actuating signal comprise data concerning at least one of a transmission ratio, vehicle mass and road slope.

3. Process according to claim 1 wherein the controller-internal desired longitudinal acceleration is determined as a function of desired longitudinal acceleration and actual longitudinal velocity, and is limited to a definable tolerance about actual longitudinal velocity.

4. Process according to claim 1, further comprising:

in addition to a desired drive train actuating signal, determining a brake system actuating signal based on a desired drive train actuating signal and the momentary brake system actuating signal; and

determining a binary brake system control signal corresponding to activating and deactivating the brake system, such that the brake system is activated only when a required vehicle deceleration cannot be achieved by engine braking alone.

5. A longitudinal dynamics control system for a motor vehicle, which generates a drive train actuating signal based on input data indicative of a desired longitudinal acceleration and of actual vehicle driving conditions, said longitudinal dynamics control system comprising:

a first stage for determining controller-internal values for a desired longitudinal acceleration and a desired longitudinal velocity; and

a second stage connected downstream from the first stage, said second stage comprising an inverse characteristic vehicle longitudinal dynamics diagram unit, which uses an inverse characteristic vehicle longitudinal dynamics diagram to determine a desired drive train actuating signal based on the controller-internal desired longitudinal velocity values, desired longitudinal acceleration values, and fed actual driving condition data; and

first units connected on the output side of the second stage, which derive the drive train actuating signal from the desired drive train actuating signal.

6. System according to claim 5, further comprising a second unit for drive/coasting operation determination, connected behind the inverse characteristic vehicle longitudinal dynamics diagram unit, which second unit uses the desired drive train actuating signal and a returned brake system actuating signal to generate a modified desired drive train actuating signal and a binary brake system control signal based on a comparison of the desired drive train actuating signal and a minimal drive train actuating signal, a comparison between the brake system actuating signal and a minimal brake system actuating signal, and a previous value of the binary brake system control signal.

7. The process according to claim 6, wherein said characteristic inverse vehicle longitudinal dynamics diagram is prepared by:

first, performing a plurality of measurement runs with said vehicle;

second, recording at least drive train actuating signals for each measurement run as well as a plurality of vehicle longitudinal dynamic response parameters during each measurement run;

third, using said recorded drive train actuating signals and vehicle longitudinal dynamic response parameters as support points for generating a multidimensional vehicle longitudinal dynamic diagram, which determines a response of said vehicle to an input drive train actuating signal; and

inverting said vehicle longitudinal dynamic diagram whereby an input of vehicle response parameters determines and output drive train actuating signal.

8. The process according to claim 7 wherein said third step comprises using one of neuronal training methods and fuzzy logic techniques to generate said vehicle longitudinal dynamic diagram.