Control apparatus for automatic transmission and control method therefore

Claim 2

A control apparatus for an automatic transmission mounted on a vehicle having a vehicle power train composed of an engine and an automatic transmission having a torque converter, and detecting means for detecting an engine rotational speed and an engine load of said vehicle power train and a vehicle speed of the vehicle, said control apparatus controlling said vehicle power train using signals detected by said detecting means, which control apparatus comprises: characteristic memory means for storing an output power characteristic of the engine; and means for obtaining a driving shaft torque in a first gear ratio before a gear shift of the automatic transmission, based on at least said engine rotational speed and said engine load detected by said detecting means and said output power characteristic stored in said characteristic memory means, estimating driving shaft torque in a second gear ratio after a gear shift of the automatic transmission, based on said engine load and said vehicle speed, and outputting a gear shifting signal to said automatic transmission at a time when said driving shaft torque before said gear shift falls below the value of said driving shaft torque after said gear is shifted, plus a certain predetermined value.

Claim 3

A control apparatus for an automatic transmission according to claim 1, wherein: when at least one signal detected by said detecting means becomes larger than a certain value set in a vicinity of a preset maximum value, a gear shifting signal is output to said automatic transmission at a time when the engine rotating speed falls below a preset maximum limit value for said engine rotating speed, by a certain amount.

Claim 4

A control apparatus for an automatic transmission according to claim 1, wherein: when at least one signal detected by said detecting means becomes smaller than a certain value set in a vicinity of a preset minimum value, a gear shifting signal is output to said automatic transmission at a time when the vehicle speed becomes greater than a limit vehicle speed during idling running, by a certain value.

Claim 5

A control apparatus for an automatic transmission mounted on a vehicle having a vehicle power train composed of an engine and a torque converter and an automatic transmission, and detecting means for detecting an operating state of said vehicle power train and a running state of the vehicle, controlling said vehicle power train using signals detected by said detecting means, which comprises: characteristic memory means for storing am engine output power characteristic, a torque converter characteristic and a fuel consumption characteristic; and means for calculating a fuel consuming rate before gear shift, estimating an engine torque and an engine rotating speed after gear shift, based on engine rotating speed and engine load detected by said detecting means and said engine output power characteristic, said torque converter characteristic and said fuel consumption characteristic stored in said characteristic memory means, estimating a fuel consuming rate after gear shift, based on engine torque and engine rotating speed, and outputting a gear shifting signal to said automatic transmission at a time when said fuel consuming rate before gear shift becomes larger than said fuel consuming rate after gear shift.

Claim 6

A control apparatus for an automatic transmission mounted on a vehicle having a vehicle power train composed of an engine and a torque converter and an automatic transmission, and detecting means for detecting an operating state of said vehicle power train and a running state of the vehicle, controlling said vehicle power train using signals detected by said detecting means, which comprises: characteristic memory means for storing am engine output power characteristic, a torque converter characteristic and a fuel consumption characteristic; and means for calculating a fuel consuming rate before gear shift, estimating an engine torque and an engine rotating speed after gear shift, based on engine rotating speed and engine load detected by said detecting means and said engine output power characteristic, said torque converter characteristic and said fuel consumption characteristic stored in said characteristic memory means, estimating a fuel consuming rate after gear shift, based on engine torque and engine rotating speed, and outputting a gear shifting signal to said automatic transmission at a time when said fuel consuming rate before gear shift becomes larger than said fuel consuming rate after gear shift.

Claim 7

A control apparatus for an automatic transmission mounted on a vehicle having a vehicle power train composed of an engine and an automatic transmission having a torque converter, and detecting means for detecting an operating state of said vehicle power train and a running state of the vehicle, said control apparatus controlling said vehicle power train using signals detected by said detecting means, which control apparatus comprises: first control means having first characteristic memory means for storing vehicle characteristics; means for obtaining a driving shaft torque before gear shift, based on at least signals indicative of engine rotating speed, engine load among said operating state or said running state detected by said detecting means and an engine output power characteristic stored in said first characteristic memory means, estimating a driving shaft torque after gear shift, based on signals indicative of engine load and vehicle speed, and outputting a gear shifting signal to said automatic transmission at a time when said driving shaft torque before gear shift falls below said driving shaft torque, plus a certain value; and second control means having second characteristic memory means, for storing an engine output power characteristic, a torque converter characteristic and a fuel consumption characteristic, calculating a fuel consuming rate before gear shift, estimating an engine torque and an engine rotating speed after gear shift based on signals indicative of engine rotating speed, engine load detected by said detecting means and said engine output power characteristic, said torque converter characteristic and said fuel consumption characteristic stored in said second characteristic memory means, estimating a fuel consuming rate after gear shift using said engine torque and said engine rotating speed, and outputting a gear shifting signal to said automatic transmission at a time when said fuel consuming rate before gear shift becomes larger than said fuel consuming rate after gear shift; said first control means and said second control means being switched depending on said running state detected by said detecting means.

Claim 8

A control apparatus for an automatic transmission mounted on a vehicle having a vehicle power train composed of an engine and an automatic transmission having a torque converter, and detecting means for detecting an operating state of said vehicle power train and a running state of the vehicle, said control apparatus controlling said vehicle power train using signals detected by said detecting means, which control apparatus comprises: first control means having first characteristic memory means for storing vehicle characteristics; means for obtaining a driving shaft torque before gear shift, based on at least signals indicative of engine rotating speed, engine load among said operating state or said running state detected by said detecting means and an engine output power characteristic stored in said first characteristic memory means, estimating a driving shaft torque after gear shift, based on signals indicative of engine load and vehicle speed, and outputting a gear shifting signal to said automatic transmission at a time when said driving shaft torque before gear shift falls below said driving shaft torque, plus a certain value; and second control means having second characteristic memory means, for storing an engine output power characteristic, a torque converter characteristic and a fuel consumption characteristic, calculating a fuel consuming rate before gear shift, estimating an engine torque and an engine rotating speed after gear shift based on signals indicative of engine rotating speed, engine load detected by said detecting means and said engine output power characteristic, said torque converter characteristic and said fuel consumption characteristic stored in said second characteristic memory means, estimating a fuel consuming rate after gear shift using said engine torque and said engine rotating speed, and outputting a gear shifting signal to said automatic transmission at a time when said fuel consuming rate before gear shift becomes larger than said fuel consuming rate after gear shift; said first control means and said second control means being switched depending on said running state detected by said detecting means.

Claim 9

A control apparatus for an automatic transmission according to claim 5, wherein: switching of said first control means and said second control means is performed using at least one of signals expressing engine state.

Claim 10

A control apparatus for an automatic transmission according to claim 6, wherein: said signal expressing engine state is at least one of acceleration pedal opening, engine load, suction air flow rate, fuel injector pulse width, engine rotating speed and engine torque.

Claim 11

A control apparatus for an automatic transmission according to claim 6, wherein: said first control means is switched on when said signal expressing engine state is smaller than a given value, and said second control means is switched on when said signal expressing engine state is larger than said given value.

Claim 12

A control apparatus for an automatic transmission according to claim 6, wherein: switching of said first control means and said second control means is performed depending on the magnitude of change per unit time in at least one of acceleration pedal opening, engine load, suction air flow rate, fuel injector pulse width, engine rotating speed and engine torque.

Claim 13

A control apparatus for an automatic transmission according to claim 9, wherein: a first gear shifting instruction value is obtained by said first control means and a second gear shifting instruction value is obtained by said second control means depending on the magnitude of change per unit time in at least one of acceleration pedal opening, engine load, suction air flow rate, fuel injector pulse width, engine rotating speed and engine torque, a third gear shifting instruction value between the both values being obtained through weighted composition, a gear shifting signal being output to said automatic transmission based on said third gear shifting instruction value.

Claim 14

A control apparatus for an automatic transmission mounted on a vehicle having a vehicle power train composed of an engine and a torque converter and an automatic transmission, and detecting means for detecting an operating state of said vehicle power train and a running state of the vehicle, said control apparatus controlling said vehicle power train based on signals detected by said detecting means, which control apparatus comprises: characteristic memory means for storing vehicle characteristics; means for obtaining a turbine torque before gear shift, based on at least engine rotating speed, engine load among said operating state or said running state detected by said detecting means and an engine output power characteristic stored in said characteristic memory means, estimating a turbine torque after gear shift, using the engine load and the vehicle speed before gear shift down to a next lower speed gear position from a gear position before the gear shift when said turbine torque is larger than turbine torque corresponding to the gear position before the gear shift, outputting a gear shifting signal to said automatic transmission when said turbine torque is smaller than turbine torque corresponding to the gear position before the gear shift.

Claim 15

A control apparatus for an automatic transmission mounted on a vehicle having a vehicle power train composed of an engine and a torque converter and an automatic transmission, and detecting means for detecting an operating state of said vehicle power train and a running state of the vehicle, said control apparatus controlling said vehicle power train based on signals detected by said detecting means, which control apparatus comprises: characteristic memory means for storing vehicle characteristics; means for obtaining a turbine torque before gear shift, based on at least engine rotating speed, engine load among said operating state or said running state detected by said detecting means and an engine output power characteristic stored in said characteristic memory means, estimating a turbine torque after gear shift, using the engine load and the vehicle speed before gear shift down to a next lower speed gear position from a gear position before the gear shift when said turbine torque is larger than turbine torque corresponding to the gear position before the gear shift, outputting a gear shifting signal to said automatic transmission when said turbine torque is smaller than turbine torque corresponding to the gear position before the gear shift.

Claim 18

A method of controlling a control apparatus for an automatic transmission according to claim 12, wherein: when at least one signal detected by said detecting means becomes larger than a certain value set in a vicinity of a preset maximum value, a gear shifting signal is output to said automatic transmission at a time when the engine rotational speed falls below a preset maximum limit value for said engine rotational speed by a certain amount.

Claim 19

A method of controlling a control apparatus for an automatic transmission according to claim 12, wherein: when at least one signal detected by said detecting means becomes smaller than a certain value set in a vicinity of a preset minimum value, a gear shifting signal is output to said automatic transmission at a time when the vehicle speed becomes greater than a limit vehicle speed during idling running, by a certain value.

Claim 24

A method of controlling a control apparatus for an automatic transmission according to claim 16, wherein: switching of said first control method and said second control method is performed using at least one of signals expressing engine state.

Claim 25

A method of controlling a control apparatus for an automatic transmission according to claim 17, wherein: said signal expressing engine state is at least one of acceleration pedal opening, engine load, suction air flow rate, fuel injector pulse width, engine rotating speed and engine torque.

Claim 26

A method of controlling a control apparatus for an automatic transmission according to claim 17, wherein: said first control method is switched on when said signal expressing engine state is smaller than a given value, and said second control method is switched on when said signal expressing engine state is larger than said given value.

Claim 27

A method of controlling a control apparatus for an automatic transmission according to claim 17, wherein: switching of said first control method and said second control method is performed depending on the magnitude of change per unit time in at least one of acceleration pedal opening, engine load, suction air flow rate, fuel injector pulse width, engine rotating speed and engine torque.

Claim 28

A method of controlling a control apparatus for an automatic transmission according to claim 20, wherein: a first gear shifting instruction value is obtained by said first control method and a second gear shifting instruction value is obtained by said second control method depending on magnitude of change per unit time in at least one of acceleration pedal opening, engine load, suction air flow rate, fuel injector pulse width, engine rotating speed and engine torque, a third gear shifting instruction value between both values being obtained through weighted composition, a gear shifting signal being output to said automatic transmission based on said third gear shifting instruction value.