Method for controlling AMT system including speed sensor signal fault detection and tolerance

Claim 3

The method of claim 1 wherein the identity of a faulty input signal indicative of the rotational speed of said engine, input shaft and output shaft is sensed by calculating the values of: ##EQU2## where: ES=the value of the input signal indicative of rotational engine speed, IS=the value of the input signal indicative of rotational input shaft speed, OS=the value of the input signal indicative of rotational output shaft speed, and GR=an input signal value indicative of the known currently engaged gear ratio.

Claim 4

The method of claim 2 wherein at least two of ES, IS and OS are determined to be faulty if: E 1 is greater than 0, E 2 is greater than 0, E 3 =0, and IS=GR * OS=0.

Claim 5

The method of claim 2 wherein at least two of ES, IS and OS are determined to be faulty if: E 1 is greater than 0, E 2 =0, E 3 =is greater than 0, and ES=OS=0.

Claim 6

The method of claim 2 wherein at least two of ES, IS and OS are determined to be faulty if: E 1 =0, E 2 is greater than 0, E 3 is greater than 0, and ES=IS=0.

Claim 7

The method of claim 2 wherein OS is determined to be faulty, and ES and IS are determined to be not faulty if: E 1 =0, E 2 is greater than 0, E 3 is greater than 0, and ES=IS ≠0.

Claim 8

The method of claim 6 wherein said input signals additionally include (6) an input signal indicative of actuation of the vehicle brakes, and wherein if OS is determined to be faulty, and ES and IS are determined to be not faulty, the program is modified by letting OS=IS/GR if the transmission is engaged in a known gear ratio, letting OS=0 if a shift into transmission neutral is requested, causing a value equal to d(OS/GR)/dt to be calculated prior to change gear shift operations and letting OS=(IS/GR)/+K where K is proportional to the time since a shift operation commensed and to the value of d(IS/GR)/dt at initiation of the shift if d(IS/GR)/dt is less than zero and the vehicle brakes are applied, otherwise letter OS=last known value of IS/GR.

Claim 9

The method of claim 6 wherein at least two of ES, IS and OS are determined to be faulty if: E 1 =0, E 2 is greater than 0, E 3 is greater than 0, and ES=OS=0.

Claim 10

The method of claim 8 wherein said input signals additionally include (6) an input signal indicative of actuation of the vehicle brakes, and wherein if OS is determined to be faulty, and ES and IS are determined to be not faulty, the program is modified by letting OS=IS/GR if the transmission is engaged in a known gear ratio, letting OS=0 if a shift into transmission neutral is requested, causing a value equal to d(OS/GR)/dt to be calculated prior to change gear shift operations, and letting OS=(IS/GR)/+K where K is proportional to the time since a shift operation commensed and to the value of d(IS/GR)/dt at initiation of the shift if d(IS/GR)/dt is less than zero and the vehicle brakes are applied, otherwise letter OS=last known value of IS/GR.

Claim 11

The method of claim 2 wherein IS is determined to be faulty, and ES and OS are determined to be not faulty, of: E 1 is greater than 0, E 2 =0, E 3 =is greater than 0, and ES=GR * OS≠0.

Claim 12

The method of claim 10 wherein OS is determined to be faulty, and ES and IS are determined to be not faulty if: E 1 =0, E 2 is greater than 0, E 3 =is greater than 0, and ES=OS=≠0.

Claim 13

The method of claim 11 wherein at least two of ES, IS and OS are determined to be faulty if: E 1 =0, E 2 =is greater than 0, E 3 =is greater than 0, and ES=OS=0.

Claim 14

The method of claim 10 wherein if IS is determined to be faulty, and ES and OS are determined to be not faulty, the program is modified by letting IS=ES if the coupling is fully engaged, letting IS=OS * GR if the transmission is engaged in a known gear ratio, letting IS=ES if a shift is in progress and if GR * OS is greater than engine idle speed, and otherwise letting IS=0.

Claim 15

The method of claim 13, wherein the program is additionally modified by minimizing intervals of coupling disengagement.

Claim 16

The method of claim 10 wherein at least two of ES, IS and OS are determined to be faulty if: E 1 is greater than 0, E 2 =0, E 3 is greater than 0, and ES=OS=0.

Claim 17

The method of claim 15 wherein if IS is determined to be faulty, and ES and OS are determined to be not faulty, the program is modified by letting IS=ES if the coupling is fully engaged, letting IS=OS * GR if the transmission is engaged in a known gear ratio, letting IS=OS * GR if the transmission is engaged in a known gear ratio, letting IS=ES if a shift is in progress and if GR * OS is greater than engine idle speed and otherwise letting IS=0.

Claim 18

The method of claim 16, wherein the program is additionally modified by minimizing intervals of coupling disengagement.

Claim 19

The method of claim 2 wherein ES is determined to be faulty, and IS and OS are determined to be not faulty if: E 1 is greater than 0; E 2 is greater than 0; E 3 =0; and IS=GR * OS≠0.

Claim 20

The method of claim 18 wherein if ES is determined to be faulty, and IS and OS are determined to be not faulty, the program is modified by letting ES=IS if the coupling is fully engaged and using the sensed value of IS prior to clutch disengagement if the clutch is not fully engaged.

Claim 21

The method of claim 18 wherein at least two of ES, IS and OS are determined to be faulty if: E 1 =0, E 2 is greater than 0, E 3 is greater than 0, and ES=OS=0.

Claim 22

The method of claim 20 wherein at least two of ES, IS and OS are determined to be faulty if: E 1= 0, E 2 is greater than 0, E 3 is greater than 0, and ES=OS=0.

Claim 23

The method of claim 18 wherein at least two of ES, IS and OS are determined to be faulty if: E 1 is greater than 0, E 2 is greater than 0, E 3= 0, and IS=OS=0.

Claim 24

The method of claim 22 wherein if ES is determined to be faulty, and IS and OS are determined to be not faulty, the program is modified by letting ES=IS if the coupling is fully engaged and using the sensed value of IS prior to clutch disengagement if the clutch is not fully engaged.

Claim 25

The method of claim 18 wherein IS is determined to be faulty, and ES and OS are determined to be not faulty, if: E 1 is greater than 0 E 2 =0, E 3 is greater than 0, and ES=GR * OS≠0.

Claim 26

The method of claim 24 wherein at least two of ES, IS and OS are determined to be faulty if: E 1 is greater than 0, E 2= 0 E 3 is greater than 0, and ES=OS=0.

Claim 27

The method of claim 24 wherein OS is determined to be faulty, and ES and IS are determined to be not faulty if: E 1 =0, E 2 is greater than 0, E 3 is greater than 0, and ES=OS≠0.

Claim 28

The method of claim 26 wherein at least two of ES, IS and OS are determined to be faulty if: E 1 =0, E 2 is greater than 0, E 3 is greater than 0, and ES=OS=0.

Claim 29

The method of claim 27 wherein if IS is determined to be faulty, and ES and OS are determined to be not faulty, the program is modified by letting IS=ES if the coupling is fully engaged, letting IS=OS * GR if the transmission is engaged in a known gear ratio, letting IS=ES if a shift is in progress and if GR * OS is greater than engine idle speed, and otherwise letting IS=0.

Claim 30

The method of claim 27 wherein said input signals additionally include (6) an input signal indicative of indicative actuation of the vehicle brakes, and wherein if OS is determined to be faulty, and ES and IS are determined to be not faulty, the program is modified by letting OS=IS/GR if the transmission is engaged in a known gear ratio, letting OS=0 if a shift into transmission neutral is requested, causing a value equal to d(OS/GR)/dt to be calculated prior to change gear shift operations, and letting OS=(IS/GR)/+K where K is proportional to the time since a shift algorithm and to the value of d(IS/GR)/dt at initiation of the shift if d(IS/GR)/dt is less than zero and the vehicle brakes are applied, otherwise letting OS=last known value if IS/GR.

Claim 31

The method of claim 27 wherein if ES is determined to be faulty, and IS and OS are determined to be not faulty, the program is modified by letting ES=IS if the coupling is fully engaged and using the sensed value of IS prior to clutch disengagement if the clutch is not fully engaged.

Claim 32

The method of claim 30 wherein said input signals additionally include (6) an input signal indicative of actuation of the vehicle brakes, and wherein if OS is determined to be faulty, and ES and IS are determined to be not faulty, the program is modified by letting OS=IS/GR if the transmission is engaged in a known gear ratio, letting OS=0 if a shift into transmission neutral is requested, causing a value equal to d(OS/GR)/dt to be calculated prior to change gear shift operations, and letting OS=(IS/GR)/+K where K is proportional to the time since a shift algorithm and to the value of d(IS/GR)/dt at initiation of the shift if d(IS/GR)/dt is less than zero and the vehicle brakes are applied, otherwise letting OS=last known value of IS/GR.

Claim 33

The method of claim 30 wherein if IS is determined to be faulty, and ES and OS are determined to be not faulty, the program is modified by letting IS=ES if the coupling is fully engaged, letting IS=OS * GR if the transmission is engaged in a known gear ratio, letting IS=ES if a shift is in progress and if GR * OS is greater than engine idle speed, and otherwise letting IS=0.

Claim 34

The method of claim 32 wherein said input signals additionally include (6) an input signal indicative of actuation of the vehicle brakes, and wherein if OS is determined to be faulty, and ES and IS are determined to be not faulty, the program is modified by letting OS=IS/GR if the transmission is engaged in a known gear ratio, letting OS=0 if a shift into transmission neutral is requested, causing a value equal to d(OS/GR)/dt to be calculated prior to change gear shift operations, and letting OS=(IS/GR)/+K where K is proportional to the time since a shift algorithm and to the value of d(IS/GR)/dt at initiation of the shift if d(IS/GR)/dt is less than zero and the vehicle brakes are applied, otherwise letting OS=last known value of IS/GR.

Claim 35

A control system for controlling an automatic mechanical transmission system for devices having a throttle-controlled engine, a transmission having a plurality of gear ratio combinations selectively engagable between a transmission input shaft and a transmission output shaft, said transmission input shaft being operatively connected to said engine by means of a selectably engagable and disengagable coupling providing a substantially nonslipping driving connection between said engine and said input shaft in the fully engaged condition thereof, said automatic mechanical transmission system comprising an information processing unit having means for receiving a plurality of input signals including (1) an input signal indicative of the fully engaged condition of the coupling; (2) an input signal indicative of the currently engaged gear ratio of the transmission; (3) an input signal indicative of the rotational speed of the engine, and (4) an input signal indicative of the rotational speed of the transmission input shaft; and (5) an input signal indicative of the rotational speed of the transmission output shaft, said processing unit including means for processing said input signals in accordance with a program and for generating output signals whereby said transmission system is operated in accordance with said program, and means associated with said transmission system effective to actuate said transmission system effective to actuate said transmission system to effect engagement of said gear ratio combinations in response to said output signals from said processing unit, the control system characterized by: means defining logic rules effect when said transmission is engaged in a known gear ratio and said coupling is fully engaged to sense the presence or absence of faulty input signals indicative of the rotational speeds of said engine, input shaft and output shaft if the following relationship is false: ES=IS=GR * OS wherein: ES=the value of the input signal indicative of rotational engine speed, IS=the value of the input signal indicative of rotational input shaft speed, OS=the value of the input signal indicative of rotational output shaft speed, and GR=a signal indicative of the known currently engaged gear ratio; and means defining logic rules effective if only one of said input signals indicative of the rotational speeds of said engine, input shaft and output shaft is determined to be faulty, to ignore said identified faulty input signal and to process said remaining input signals to determine an acceptable value for the identified faulty input signal.

Claim 36

A control system for controlling an automatic mechanical transmission system for devices having a throttle-controlled engine, a transmission having a plurality of gear ratio combinations selectively engagable between a transmission input shaft and a transmission output shaft, said transmission input shaft being operatively connected to said engine by means of a selectably engagable and disengagable coupling providing a substantially nonslipping driving connection between said engine and said input shaft in the fully engaged condition thereof, said automatic mechanical transmission system comprising an information processing unit having means for receiving a plurality of input signals including (1) an input signal indicative of the fully engaged condition of the coupling; (2) an input signal indicative of the currently engaged gear ratio of the transmission; (3) an input signal indicative of the rotational speed of the engine, and (4) an input signal indicative of the rotational speed of the transmission input shaft; and (5) an input signal indicative of the rotational speed of the transmission output shaft, said processing unit including means for processing said input signals in accordance with a program and for generating output signals whereby said transmission system is operated in accordance with said program, and means associated with said transmission system effective to actuate said transmission system effective to actuate said transmission system to effect engagement of said gear ratio combinations in response to said output signals from said processing unit, the control system characterized by: means defining logic rules effect when said transmission is engaged in a known gear ratio and said coupling is fully engaged to sense the presence or absence of faulty input signals indicative of the rotational speeds of said engine, input shaft and output shaft if the following relationship is false: ES=IS=GR * OS wherein: ES=the value of the input signal indicative of rotational engine speed, IS=the value of the input signal indicative of rotational input shaft speed, OS=the value of the input signal indicative of rotational output shaft speed, and GR=a signal indicative of the known currently engaged gear ratio; and means defining logic rules effective if only one of said input signals indicative of the rotational speeds of said engine, input shaft and output shaft is determined to be faulty, to ignore said identified faulty input signal and to process said remaining input signals to determine an acceptable value for the identified faulty input signal.

Claim 37

The control system of claim 34 wherein the identity of a faulty input signal indicative of the rotational speed of said engine, input shaft and output shaft is sensed by calculating the values of: ##EQU3##

Claim 38

The control system of claim 35 wherein ES is determined to be faulty, and IS and OS are determined to be not faulty if: E 1 is greater than 0; E 2 is greater than 0; E 3 =0; and IS=GR * OS=0.

Claim 39

The control system of claim 36 wherein if ES is determined to be faulty, and IS and OS are determined to be not faulty, the program is modified by letting ES =IS if the coupling is fully engaged and using the sensed value of IS prior to clutch disengagement if the clutch is not fully engaged.

Claim 40

The control system of claim 35 wherein IS is determined to be faulty, and ES and OS are determined to be not faulty, if: E 1 is greater than 0 E 2 =0, E 3 is greater than 0, and ES=GR * OS=0.

Claim 41

The control system of claim 38 wherein said input signals additionally include (6) an input signal indicative of actuation of the vehicle brakes, and wherein if OS is determined to be faulty, and ES and IS are determined to be not faulty, the program is modified by letting OS=IS/GR if the transmission is engaged in a known gear ratio, letting OS=0 if a shift into transmission neutral is requested, causing a value equal to d(OS/GR)/dt to be calculated prior to change gear shift operations and letting OS=(IS/GR)/+K where K is proportional to the time since a shift operation commenced and to the value of d(IS/GR)/dt at initiation of the shift if d(IS/GR)/dt is less than zero and the vehicle brakes are applied, otherwise letting OS=last known value of IS/GR.

Claim 42

The control system of claim 35 wherein IS is determined to be faulty, and ES and OS are determined to be not faulty, if: E 1 is greater than 0 E 2 =0, E 3 is greater than 0, and ES=GR * OS=0.

Claim 43

The control system of claim 40 wherein if IS is determined to be faulty, and ES and OS are determined to be not faulty, the program is modified by letting IS =ES if the coupling is fully engaged, letting IS=OS * GR if the transmission is engaged in a know gear ratio, letting IS=ES if a shift is in progress and if GR * OS is greater than engine idle speed, and otherwise letting IS=0.

Claim 44

The control system of claim 41 wherein said program is additionally modified by minimizing intervals of coupling disengagement.