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Method for indicating speed change operations to be performed by a driver of a car

  • US 4,677,556 A
  • Filed: 03/15/1984
  • Issued: 06/30/1987
  • Est. Priority Date: 01/12/1983
  • Status: Expired due to Term
First Claim
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1. An apparatus for indicating a gear shifting operation for a vehicle transmission, comprising:

  • means for determining an air flow;

    means for determining an engine speed;

    processing means for;

    calculating current engine load from the intake air flow and the engine speed,comparing said calculated engine load with a predetermined engine load constant;

    again calculating engine load if said comparision determines that said current engine load is less than or equal to said predetermined constant;

    calculating a current shift position from current engine speed, current vehicle speed and the known transmission gear ratio;

    determining a first engine load operation function and a second operation engine load function from predetermined equal fuel consumption rate curves;

    comparing said first engine load operation function with said current engine load; and

    determining if the vehicle is running on a slope which is steeper than a predetermined amount, by using the vehicle speed, and air flow;

    shift determination means for indicating a shift-down operation to be performed if said first operation function has a value greater than said current engine load, performing additional steps for potential shift-up operation indication if said first operation function has a value less than or equal to said current engine load, calculating current engine horsepower from said current engine speed and current engine load Q/N and inhibiting shift up and shift down operations when said vehicle is determined to be running on said slope steeper than a predetermined amount;

    and wherein said processing means is also for calculating expected engine speed necessary for maintaining said current vehicle speed if there is a one shift-up operation performed on said transmission.

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