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Vehicle speed control device and method

  • US 8,370,042 B2
  • Filed: 07/09/2008
  • Issued: 02/05/2013
  • Est. Priority Date: 07/11/2007
  • Status: Active Grant
First Claim
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1. A vehicle speed control device comprising:

  • means for calculating a control drive force for maintaining a speed of a vehicle to a set speed; and

    means for conducting a cruise control which makes the vehicle travel by the control drive force calculated by the calculating means,wherein the calculating means calculates a drive force including a feedforward component corresponding to the set speed and a travel resistance against travel of the vehicle, and a feedback component corresponding to a deviation between the set speed and an actual speed of the vehicle as the control drive force,wherein the conducting means interrupts the cruise control when accelerator operation is conducted by a driver during the cruise control, and a requested drive force requested by the accelerator operation exceeds the control drive force, and restarts the cruise control at a time when the requested drive force becomes lower than the control drive force,wherein the calculating means detects at least a slope of a road on which the vehicle travels as the travel resistance,the calculating means checks whether a detected value of the slope is within a limit range that is defined by Law or Regulation, and uses no detected value in the calculation of the feedforward component or uses a value that is limited within the limit range, andwherein the limit range is stored in a navigation ECU;

    wherein the calculating means interrupts the calculation of the feedback component while the requested drive force exceeds the control drive force, andwherein the calculating means calculates a proportional component and an integral component as the feedback component, restarts only the calculation of the proportional component at a time when the requested drive force becomes lower than the control drive force after exceeding the control drive force, limits the feedback component to a limit deceleration until the deceleration corresponding to the calculation result of the proportional component becomes lower than a given limit deceleration, and cancels the limit and restarts the calculation of the integral component at a time when the deceleration becomes lower than the limit deceleration.

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