Cruise control device and cruise control method

• US 10,428,937 B2
• Filed: 03/18/2016
• Issued: 10/01/2019
• Est. Priority Date: 03/26/2015
• Status: Active Grant

• Current Assignee: Isuzu Motors Limited
• Original Assignee: Isuzu Motors Limited
• Inventors: Ishiguro, Shinichi, Nishimura, Nobuyuki, Nishikimi, Masao
• Primary Examiner(s): Pang, Roger L
• Application Number:
  US15/561,234
• Publication Number:
  US 20180051802A1
• Time in Patent Office: 1,292 Days
• Field of Search: 701 57
• CPC Class Codes: B60W 30/143 Speed control B60W30/16 takes precedence
• CPC Class Codes: B60Y 2300/143 Speed control
• CPC Class Codes: F16H 2059/142 of driving resistance calculated from weight, slope, or the like
• CPC Class Codes: F16H 2059/663 Road slope
• CPC Class Codes: F16H 2059/666 Determining road conditions by using vehicle location or position, e.g. from global navigation systems [GPS]
• CPC Class Codes: F16H 2061/022 Calculation or estimation of optimal gear ratio, e.g. best ratio for economy drive or performance according driver preference, or to optimise exhaust emissions
• CPC Class Codes: F16H 2061/163 Holding the gear for delaying gear shifts under unfavorable conditions, e.g. during cornering
• CPC Class Codes: F16H 59/18 dependent on the position of the accelerator pedal
• CPC Class Codes: F16H 59/44 dependent on machine speed of the machine, e.g. the vehicle
• CPC Class Codes: F16H 59/66 Road conditions, e.g. slope, slippery
• CPC Class Codes: F16H 61/0213 characterised by the method for generating shift signals
• CPC Class Codes: F16H 61/16 Inhibiting or initiating shift during unfavourable conditions, e.g. preventing forward reverse shift at high vehicle speed, preventing engine over speed unintentional control input F16H61/18

Abstract

A road information acquisition unit (12a) acquires information about the road in a prescribed segment in front, a vehicle information acquisition unit (12b) acquires information about the vehicle (1), a velocity prediction unit (12c) predicts, on the basis of the road information and the information about the vehicle (1), the changes in the vehicle velocity that would be brought about in the prescribed segment in the case of travelling the prescribed segment in a first gear, and a shift control unit (12d) which maintains the first gear if the condition is satisfied that the predicted vehicle velocity exhibits a minimum value other than at the ends of the prescribed segment and the minimum value is greater than the delay speed, which is set to a value less than a predetermined velocity set as the velocity that would result from downshifting.

Claims

1. A travel control device that controls a transmission to perform a downshift from a first transmission gear to a second transmission gear, the travel control device comprising:

a road information acquiring section that acquires information about a road in a predetermined section ahead of a vehicle travelling with the first transmission gear;

a vehicle information acquiring section that acquires information about the vehicle;

a speed estimating section that estimates, based on the information about the road and the information about the vehicle, a transition of a vehicle speed in the predetermined section in a case where the vehicle travels in the predetermined section with the first transmission gear; and

a transmission control section that controls the transmission to maintain the first transmission gear without performing a downshift from the first transmission gear to the second transmission gear when a condition where the transition of the vehicle speed estimated by the speed estimating section has a minimum value at a position other than an end of the predetermined section, and the minimum value is larger than a grace speed set at a value smaller than a speed set in advance as a speed at which the downshift is performed is satisfied,

wherein the transition of the vehicle speed estimated by the speed estimating section is a transition of the vehicle speed when the vehicle travels in the predetermined section with a maximum accelerator opening.

2. The travel control device according to claim 1, wherein the road information acquiring section determines the predetermined section in accordance with a present speed of the vehicle.

3. The travel control device according to claim 1, wherein the transmission control section releases the control of the transmission to maintain the first transmission gear when a speed of the vehicle reaches a target speed set in advance.

4. A travel control method for controlling a transmission to perform a downshift from a first transmission gear to a second transmission gear, the method comprising:

acquiring information about a road in a predetermined section ahead of a vehicle travelling with the first transmission gear;

acquiring information about the vehicle;

estimating, based on the information about the road and the information about the vehicle, a transition of a vehicle speed in the predetermined section when the vehicle travels in the predetermined section with the first transmission gear, the transition of the vehicle speed being a transition of the vehicle speed when the vehicle travels in the predetermined section with a maximum accelerator opening; and

controlling the transmission to maintain the first transmission gear without performing a downshift from the first transmission gear to the second transmission gear when a condition where the transition of the vehicle speed estimated in the estimating has a minimum value at a position other than an end of the predetermined section, and the minimum value is larger than a grace speed set at a value smaller than a speed set in advance as a speed at which the downshift is performed is satisfied.