Downhill coasting situation detecting device for automotive vehicle

• US 5,794,170 A
• Filed: 11/14/1995
• Issued: 08/11/1998
• Est. Priority Date: 11/14/1994
• Status: Expired due to Fees

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Takahashi, Hiroshi, Kuroda, Kouichi
• Primary Examiner(s): Chin, Gary
• Application Number:
  US08/557,209
• Time in Patent Office: 1,001 Days
• Field of Search: 364/426.041, 364/426.042, 364/426.043, 364/426.044, 364/431.07, 364/460, 364/461, 123/350, 123/352, 180/170, 180/176, 180/177, 180/178, 180/179, 701/93-96, 701/110, 701/300, 701/301
• US Class Current: 701/93
• 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: B60W 2520/105 Longitudinal acceleration
• CPC Class Codes: B60W 2710/0616 Position of fuel or air injector
• CPC Class Codes: F02D 2200/501 Vehicle speed
• CPC Class Codes: F02D 41/12 for deceleration F02D41/0005, F02D41/107 take precedence
• CPC Class Codes: F16H 2059/186 Coasting
• CPC Class Codes: F16H 2059/405 Rate of change of output shaft speed or vehicle speed
• CPC Class Codes: F16H 2059/506 Wheel slip
• CPC Class Codes: F16H 2061/0227 Shift map selection, i.e. methods for controlling selection between different shift maps, e.g. to initiate switch to a map for up-hill driving
• CPC Class Codes: F16H 59/24 dependent on the throttle opening
• CPC Class Codes: F16H 59/66 Road conditions, e.g. slope, slippery
• CPC Class Codes: F16H 61/21 Providing engine brake control
• CPC Class Codes: Y02T 10/60 Other road transportation technologies with climate change mitigation effect

Abstract

A downhill coasting situation detecting device for an automotive vehicle comprises a sensor for detecting an opening degree of a throttle valve for an engine of the automotive vehicle, a first derivative calculating device for calculating a first derivative of the vehicle speed, a second derivative calculating device for calculating a second derivative of the vehicle speed, and a downhill coasting situation determining device for determining that the automotive vehicle being in a downhill coasting situation in which the vehicle being coasting on a downhill road in accordance with a condition in which the opening degree of the throttle valve is zero and the first derivative of vehicle speed is positive and besides the second derivative of vehicle speed is nearly equal to zero. With the downhill coasting situation detecting device, the downhill coasting situation can be exactly detected, so that e.g. down-shifting for obtaining further engine braking can be automatically executed in the downhill coasting situation.

Claims

1. A downhill coasting situation detecting device for an automotive vehicle comprising;

a throttle valve opening degree detecting means for detecting an opening degree of a throttle valve for an engine of said automotive vehicle;

a vehicle speed changing rate calculating means for calculating a changing rate of vehicle speed of said automotive vehicle;

a vehicle speed changing rate changing rate calculating means for calculating a changing rate of changing rate of vehicle speed of said automotive vehicle; and

a downhill coasting situation determining means for determining that said automotive vehicle being in a downhill coasting situation in which said vehicle being coasting on a downhill road in accordance with a condition in which said opening degree of said throttle valve is zero, said changing rate of vehicle speed is positive and said changing rate of changing rate of vehicle speed is nearly equal to zero, based on said detected opening degree of said throttle valve, said calculated changing rate of vehicle speed and said calculated changing rate of changing rate of vehicle speed.

2. A downhill coasting situation detecting device for an automotive vehicle according to claim 1;

wherein,

said downhill coasting situation determining means determines that said automotive vehicle being in a downhill coasting situation in accordance with a condition in which a moving average of said calculated changing rate of changing rate of vehicle speed being nearly equal to zero.

3. A control device for an automotive vehicle comprising a downhill coasting situation detecting device having;

a throttle valve opening degree detecting means for detecting an opening degree of a throttle valve for an engine of said automotive vehicle;

a vehicle speed changing rate calculating means for calculating a changing rate of vehicle speed of said automotive vehicle;

a vehicle speed changing rate changing rate calculating means for calculating a changing rate of changing rate of vehicle speed of said automotive vehicle; and

a downhill coasting situation determining means for determining that said automotive vehicle being in a downhill coasting situation in which said vehicle being coasting on a downhill road in accordance with a condition in which said opening degree of said throttle valve is zero, said changing rate of vehicle speed is positive and said changing rate of changing rate of vehicle speed is nearly equal to zero, based on said detected opening degree of said throttle valve, said calculated changing rate of vehicle speed and said calculated changing rate of changing rate of vehicle speed; and

said control device further comprising a shift pattern changing means for changing a shift pattern of an automatic transmission of said vehicle based on a detection of the downhill coasting situation by the downhill coasting situation detecting device.

4. A control device for an automotive vehicle comprising a downhill coasting situation detecting device having;

a throttle valve opening degree detecting means for detecting an opening degree of a throttle valve for an engine of said automotive vehicle;

a vehicle speed changing rate calculating means for calculating a changing rate of vehicle speed of said automotive vehicle;

a vehicle speed changing rate changing rate calculating means for calculating a changing rate of changing rate of vehicle speed of said automotive vehicle; and

a downhill coasting situation determining means for determining that said automotive vehicle being in a downhill coasting situation in which said vehicle being coasting on a downhill road in accordance with a condition in which said opening degree of said throttle valve is zero, said changing rate of vehicle speed is positive and said changing rate of changing rate of vehicle speed is nearly equal to zero, based on said detected opening degree of said throttle valve, said calculated changing rate of vehicle speed and said calculated changing rate of changing rate of vehicle speed; and

said control device further comprising;

a delay calculating means for calculating an aiming delay from a point of time of an opening degree of said throttle valve being made zero to a point of time of down-shifting based on an inclination of a downhill road thereof in case of said downhill coasting situation being detected by said downhill coasting situation detecting device; and

a down-shifting directing means for directing an automatic transmission of said vehicle to execute down-shifting, in case of said downhill coasting situation still being detected by said downhill coasting situation detecting device after passing of said calculated aiming delay.

5. A control device for an automotive vehicle according to claim 4 further comprising;

a delay calculation repeating means for directing said delay calculating means to repeat said calculation of said aiming delay responding to changing of an inclination of said downhill road from a point of time of an opening degree of said throttle valve being made zero to a point of time of down-shifting.

6. A control device for an automotive vehicle according to claim 4 further comprising;

a delay correcting means for correcting said aiming delay calculated by said delay calculating means, in accordance with said vehicle speed.

7. A control device for an automotive vehicle according to claim 4 further comprising;

a down-shifted gear position releasing means for releasing an enforcement of said down-shifted gear position caused by said down-shifting directing means, in case of said throttle valve being opened by a driver of said vehicle on said downhill road.

8. A control device for an automotive vehicle according to claim 4 further comprising;

a frictional resistance determining means for determining a frictional resistance of said downhill road; and

a down-shifting inhibiting means for inhibiting an execution of down-shifting of said automatic transmission directed by said down-shifting directing means, in case of said determined frictional resistance being lower than a predetermined value.

9. A control device for an automotive vehicle comprising a downhill coasting situation detecting device having;

a throttle valve opening degree detecting means for detecting an opening degree of a throttle valve for an engine of said automotive vehicle;

a vehicle speed changing rate calculating means for calculating a changing rate of vehicle speed of said automotive vehicle;

a vehicle speed changing rate changing rate calculating means for calculating a changing rate of changing rate of vehicle speed of said automotive vehicle; and

a downhill coasting situation determining means for determining that said automotive vehicle being in a downhill coasting situation in which said vehicle being coasting on a downhill road in accordance with a condition in which said opening degree of said throttle valve is zeros, said changing rate of vehicle speed is positive and said changing rate of changing rate of vehicle speed is nearly equal to zero, based on said detected opening degree of said throttle valve, said calculated changing rate of vehicle speed and said calculated changing rate of changing rate of vehicle speed; and

said control device further comprising an ignition timing changing means for changing an ignition timing of an ignitor for an engine of said vehicle based on a detection of said downhill coasting situation by said downhill coasting situation detecting device.

10. A control device for an automotive vehicle comprising a downhill coasting situation detecting device having;

a throttle valve opening degree detecting means for detecting an opening degree of a throttle valve for an engine of said automotive vehicle;

a vehicle speed changing rate calculating means for calculating a changing rate of vehicle speed of said automotive vehicle;

a vehicle speed changing rate changing rate calculating means for calculating a changing rate of changing rate of vehicle speed of said automotive vehicle; and

a downhill coasting situation determining means for determining that said automotive vehicle being in a downhill coasting situation in which said vehicle being coasting on a downhill road in accordance with a condition in which said opening degree of said throttle valve is zero, said changing rate of vehicle speed is positive and besides said changing rate of changing rate of vehicle speed is nearly equal to zero, based on said detected opening degree of said throttle valve, said calculated changing rate of vehicle speed and said calculated changing rate of changing rate of vehicle speed; and

said control device further comprising a supplying fuel amount changing means for changing an amount of fuel supplied by a fuel supplier for an engine of the vehicle based on a detection of the downhill coasting situation by the downhill coasting situation detecting device.