Vehicle state determination integrity

• US 7,747,359 B2
• Filed: 06/20/2005
• Issued: 06/29/2010
• Est. Priority Date: 06/20/2005
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Katrak, Kerfegar K., Palazzolo, Steven D., Seifert, Mark A.
• Primary Examiner(s): Tran; Khoi
• Assistant Examiner(s): Peche; Jorge O
• Application Number:
  US11/157,207
• Publication Number:
  US 20060287777A1
• Time in Patent Office: 1,835 Days
• Field of Search: 701/1, 701/29, 701/36, 701/37, 701/41, 701/48, 701/69, 701/70, 701/78, 701/83, 701/84, 701/86, 701/90, 180/204, 180/6.2, 180/6.28, 180/252, 180/253, 180/254, 180/255, 280/5.51, 280/21.1, 280/211, 280/14.28, 280/16, 280/263, 280/264, 280/267, 280/442, 280/FOR.148, 280/5.512, 280/5.514, 280/5.515, 280/5.524, 280/124.1, 280/124.157, 280/678, 280/679, 280/680, 280/681, 280/682, 280/683, 280/684, 280/685, 280/686, 280/FOR.145, 280/402
• US Class Current: 701/1
• CPC Class Codes: G05D 1/0891 specially adapted for land vehicles

Abstract

A vehicle includes a semi-active suspension including suspension dampers controllably adjustable in accordance with electronic stability control commands and ride and handling commands. Vehicle steering response states, turning direction states and vehicle dynamics states are binary coded in respective state variables and suspension control calibrations are binary coded in calibration words. Integrity and security of state variables and calibration words are ensured in efficient binary digit resource allocation schemes.

Claims

1. Apparatus for indicating vehicle driving condition states comprising:

a memory device including predetermined bit positions for storing binary codes of a predetermined bit length, the bit length describing a quantity of bits in each of the stored binary codes; and

a computer based controller configured to;

monitor an input describing stability of the vehicle;

determine at least one valid binary code corresponding to a vehicle driving condition state comprising understeer and oversteer behavior of the vehicle based upon the monitored input; and

control a vehicle stability control system based upon the valid binary code;

wherein each valid binary code comprises a series of bit states, each bit state represented by a one or a zero, and is characterized by a predetermined ratio of corresponding bit states, the ratio describing a number of bit states equaling one and a number of bit states equaling zero and being a fixed value and common to all of the valid binary codes; and

wherein each valid binary code is differentiated from all other valid binary codes by differences between at least two complementary bits of each respective valid binary code, the differences requiring two bit transitions in opposite directions for a change in the vehicle driving condition state to be indicated.

2. The apparatus for indicating vehicle driving condition states as claimed in claim 1 wherein the predetermined bit length comprises two bits descriptive of the understeer and oversteer.

3. The apparatus for indicating vehicle driving condition states as claimed in claim 1 wherein said vehicle driving condition state further comprises neutral steer and the predetermined bit length comprises three bits descriptive of the understeer, oversteer, and neutral steer.

4. The apparatus for indicating vehicle driving condition states as claimed in claim 1 wherein said vehicle driving condition state further comprises left and right turning and the predetermined bit length comprises two bits descriptive of the left and right turning.

5. The apparatus for indicating vehicle driving condition states as claimed in claim 1 wherein said vehicle driving condition state comprises oversteer-left, oversteer-right, understeer-left and understeer-right and the predetermined bit length comprises four bits descriptive of the oversteer-left, oversteer-right, understeer-left, and understeer-right.

6. The apparatus for indicating vehicle driving condition states as claimed in claim 1 wherein said vehicle driving condition state comprises oversteer-left, oversteer-right, understeer-left, understeer-right, neutral steer-left and neutral steer-right and the predetermined bit length comprises four bits descriptive of the oversteer-left, oversteer-right, understeer-left, understeer-right, neutral steer-left, and neutral steer-right.

7. Apparatus for indicating vehicle driving condition states in a computer based controller comprising:

a memory device including predetermined bit positions for storing binary codes of a predetermined bit length, the bit length describing a quantity of bits in each of the stored binary codes;

at least one valid binary code corresponding to a vehicle driving condition state comprising understeer and oversteer behavior of the vehicle based upon a monitored input; and

a calibration memory device having a first pair of bits corresponding to jounce control and a second pair of bits corresponding to rebound control for each of the vehicle driving condition states and for each of a plurality of independently controllable suspension units wherein a first complementary arrangement of the first pair of bits corresponds to a first jounce control calibration, and wherein a second complementary arrangement of the first pair of bits corresponds to a second jounce control calibration, and wherein the first complementary arrangement of the second pair of bits corresponds to a first rebound control calibration, and wherein the second complementary arrangement of the first pair of bits corresponds to a second rebound control calibration;

wherein each valid binary code comprises a series of bit states, each bit state represented by a one or a zero, is characterized by a predetermined ratio of corresponding bit states, the ratio describing a number of bits states equaling one and a number of bit states equaling zero and being a fixed value and common to all of the valid binary codes, and is differentiated from all other valid binary codes by differences between at least two complementary bits of each respective valid binary code;

wherein jounce control describes controlling a response to compression through damper control in the independently controllable suspension units; and

wherein rebound control describes controlling a response to extension through damper control in the independently controllable suspension units.

8. The apparatus for indicating vehicle driving condition states in a computer based controller as claimed in claim 7 wherein the calibration memory device comprises a non-volatile memory device and the respective first and second pairs of bits are stored therein in predetermined ones of the first and second complementary arrangements.

9. The apparatus for indicating vehicle driving condition states in a computer based controller as claimed in claim 7 wherein the calibration memory device comprises a read-write memory device and the respective first and second pairs of bits are periodically set therein to ones of the first and second complementary arrangements as a function of predetermined vehicle operating parameters.

10. Method for indicating vehicle driving condition states within a memory device of a computer based controller comprising:

providing a first binary coded variable for conveying vehicle steering response states wherein valid binary codes share a first ratio of individual bit states and are differentiated one from another by differences between at least two complementary bits;

providing a second binary coded variable for conveying vehicle turning direction states wherein valid binary codes share a second ratio of individual bit states and are differentiated one from another by differences between at least two complementary bits; and

providing a third binary coded variable for conveying vehicle dynamics states based on combinations of vehicle steering response and turning direction states wherein valid binary codes share a third ratio of individual bit states and are differentiated one from another by differences between at least two complementary bits;

wherein the valid binary codes comprise a series of bit states, each bit state represented by a one or a zero; and

wherein the ratios describe a number of bit states equaling one and a number of bit states equaling zero.

11. The method for indicating vehicle driving condition states within a memory device of a computer based controller as claimed in claim 10 wherein vehicle steering response states comprise oversteer and understeer and the first binary coded variable comprises two bits descriptive of the oversteer and understeer.

12. The method for indicating vehicle driving condition states within a memory device of a computer based controller as claimed in claim 10 wherein vehicle steering response states comprise oversteer, understeer and neutral steer and the first binary coded variable comprises three bits descriptive of the oversteer, understeer, and neutral steer.

13. The method for indicating vehicle driving condition states within a memory device of a computer based controller as claimed in claim 10 wherein vehicle turning direction states comprise left and right and the second binary coded variable comprises two bits descriptive of the left and right vehicle turning direction states.

14. The method for indicating vehicle driving condition states within a memory device of a computer based controller as claimed in claim 10 wherein vehicle dynamics states comprise oversteer-left, oversteer-right, understeer-left and understeer-right and the third binary coded variable comprises four bits descriptive of the oversteer-left, oversteer-right, understeer-left, and understeer-right.

15. The method for indicating vehicle driving condition states within a memory device of a computer based controller as claimed in claim 10 wherein vehicle dynamics states comprise oversteer-left, oversteer-right, understeer-left, understeer-right, neutral steer-left and neutral steer-right and the third binary coded variable comprises four bits descriptive of the oversteer-left, oversteer-right, understeer-left, understeer-right, neutral steer-left, and neutral steer-right.

16. Method for indicating vehicle driving condition states within a memory device of a computer based controller comprising:

determining valid binary codes, each code corresponding to a vehicle driving condition state comprising understeer and oversteer behavior of the vehicle, comprising;

monitoring an input describing stability of the vehicle; and

determining the vehicle driving condition state based upon the monitored input;

providing a memory location within the memory device for storing the valid binary codes corresponding to the vehicle driving condition states;

storing within the memory location valid binary codes; and

utilizing the stored codes to control a vehicle stability control system;

wherein each valid binary code has a first ratio of individual bit states, each bit state represented by a one or a zero value, the ratio describing a number of bit states equaling one and a number of bit states equaling zero and being fixed and common to all of the valid binary codes, and each valid binary code is differentiated from other valid binary codes by differences between at least two complementary bits, the differences requiring two bit transitions in opposite directions for a change in the vehicle driving condition state to be indicated.

17. The method for indicating vehicle driving condition states within a memory device of a computer based controller as claimed in claim 16 wherein valid binary codes that have no identical adjacent bits correspond to preselected vehicle driving condition states desirably having the highest level of security.

18. The method for indicating vehicle driving condition states within a memory device of a computer based controller as claimed in claim 16 wherein valid binary codes that have no identical adjacent bits correspond to oversteer states.

19. The method for indicating vehicle driving condition states within a memory device of a computer based controller as claimed in claim 17 wherein preselected vehicle driving condition states desirably having the highest level of security comprise an oversteer vehicle driving condition state.

20. The method for indicating vehicle driving condition states within a memory device of a computer based controller as claimed in claim 17 wherein the preselected vehicle driving condition states desirably having the highest level of security correspond to an oversteer vehicle driving condition state.

21. The method for indicating vehicle driving condition states within a memory device of a computer based controller as claimed in claim 17 wherein vehicle driving condition states further comprise neutral steer states, and the preselected vehicle driving condition states desirably having the highest level of security correspond to an oversteer vehicle driving condition state.