Method for controlling/regulating a process in a motor vehicle and device for implementing the method

• US 20010027358A1
• Filed: 12/28/2000
• Published: 10/04/2001
• Est. Priority Date: 12/28/1999
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Schmitt, Manfred, Hess, Werner
• Granted Patent: US 6,434,465 B2
• Time in Patent Office: Days
• US Class Current: 701/1
• CPC Class Codes: B60W 30/1819 Propulsion control with control means using analogue circuits, relays or mechanical links
• CPC Class Codes: B60W 30/1882 characterised by the working point of the engine, e.g. by using engine output chart
• CPC Class Codes: B60W 50/00 Details of control systems for road vehicle drive control not related to the control of a particular sub-unit , e.g. process diagnostic or vehicle driver interfaces
• CPC Class Codes: F02D 41/2416 Interpolation techniques
• CPC Class Codes: F02D 41/2422 Selective use of one or more tables
• CPC Class Codes: F16H 2061/0096 using a parameter map
• CPC Class Codes: F16H 61/0213 characterised by the method for generating shift signals
• CPC Class Codes: G05B 13/024 in which a parameter or coefficient is automatically adjusted to optimise the performance

Abstract

A method for controlling/regulating a process in a motor vehicle, in particular a combustion process, gear-shifting process, or braking process, with the help of a characteristics grid map, which is defined by a plurality of performance quantities of the process and represented by data points that have corresponding characteristics-map values. At least one characteristics-map value is determined from the characteristics grid map in a control cycle for an operating point by first determining adjacent data points, which define an interpolation range in which the operating point lies, and by then interpolating between the adjacent data points. To reduce the computational time for interpolation, the at least one characteristics-map value is determined for the operating range within the framework of a linear interpolation based on a minimum number of data points. The minimum number of data points results from a number of the plurality of performance quantities of the process, which define the characteristics map, plus one.

Claims

1. A method for controlling a process in a motor vehicle using a characteristics grid map, comprising:

defining the characteristics grid map by a plurality of performance quantities of the process;

representing the characteristics grid map by data points having corresponding characteristics-map values; and

in a control cycle for an operating point of the process, determining at least one of the characteristics-map values as a function of the characteristics grid map by the steps of;

first determining adjacent data points defining an interpolation range in which the operating point lies, and

then interpolating between the adjacent data points,

the at least one of the characteristics-map values being determined for the operating point as a function of a minimum number of data points using a linear interpolation, the minimum number of data points being calculated from the number of the plurality of performance quantities of the process.

2. The method according to

claim 1

, wherein:

the process is one of a combustion process, a gear-shifting process, and a braking process.

3. The method according to

claim 1

, wherein:

the minimum number of data points is a function of the number of performance quantities of the process plus one.

4. The method according to

claim 1

, wherein:

the characteristics grid map is defined by two performance quantities of the process; and

in the control cycle for the operating point of the process, the at least one of the characteristics-map values is determined as a function of the characteristics map by the steps of;

first determining three adjacent data points defining an interpolation triangle in which the operating point lies, and

then interpolating between the three adjacent data points using an interpolation equation;

Y_W=(B₁*Y₁+B₂*Y₂+B₃*Y₃)/(B₁+B₂+B₃),

 

wherein B₁, B₂, and B₃ are areas of triangular sections within the interpolation triangle defined by the three adjacent data points, each of the areas of the triangular sections being defined by the operating point and any two data points of the three adjacent data points.

5. The method according to

claim 4

, wherein:

the step of determining the three adjacent data points includes the steps of;

first searching a data-point table to establish a characteristics-map grid square in which the operating point lies, and

then comparing performance-quantity components of the operating point to determine within the characteristics-map grid square the interpolation triangle.

6. The method according to

claim 1

, wherein:

the characteristics grid map is defined by three performance quantities of the process;

in the control cycle for the operating point of the process, the at least one characteristics-map value is determined as a function of the characteristics grid map by the steps of;

first determining four adjacent data points defining an interpolation tetrahedron in which the operating point lies, and

then interpolating between the four adjacent data points using the interpolation equation;

Y_W=(B₁*Y₁+B₂*Y₂+B₃*Y₃+B₄*Y₄)/(B₁+B₂+B₃+B₄)

 

wherein B₁, B₂, B₃, and B₄ are volumes of partial tetrahedrons of the interpolation tetrahedron defined by the four adjacent data points, each of the volumes of the partial tetrahedrons being defined by the operating point and any three data points of the four adjacent data points.

7. The method according to

claim 1

, further comprising:

prior to the step of interpolating, normalizing distances between two adjacent data points of the characteristics grid map to the value 1.

8. The method according to

claim 1

, further comprising:

storing the opera ting point and the at least one of the characteristics-map values at a conclusion of a control cycle; and

at a start of a subsequent control cycle, performing a check test to determine whether an operating point of the subsequent control cycle has remained the same.

9. The method according to

claim 4

, further comprising:

storing intermediate values of the interpolation equation at a conclusion of a control cycle; and

at a start of a subsequent control cycle, performing a check test to determine if an operating point of the subsequent control cycle still lies within the interpolation range.

10. A control device for controlling a process in a motor vehicle using a characteristics grid map, the device including an arrangement for performing the steps of:

defining the characteristics grid map by a plurality of performance quantities of the process;

representing the characteristics grid map by data points having corresponding characteristics-map values; and

in a control cycle for an operating point of the process, determining at least one of the characteristics-map values as a function of the characteristics grid map by the steps of;

first determining adjacent data points defining an interpolation range in which the operating point lies, and

then interpolating between the adjacent data points,

the at least one of the characteristics-map values being determined for the operating point as a function of a minimum number of data points using a linear interpolation, the minimum number of data points being calculated from the number of the plurality of performance quantities of the process.

11. The device according to

claim 10

, wherein:

the process is one of a combustion process, a gear-shifting process, and a braking process.