Method and apparatus for selecting shift points in an automated mechanical transmission

A method of controlling the initiation of a gear shift in an automated transmission of a vehicle comprising the steps of:

• a. measuring the present grade and speed of the vehicle while the vehicle is moving,
• b. determining the vehicle acceleration on the grade,
• c. determining the acceleration, .alpha., that the vehicle would exhibit for the existing gross vehicle weight if the vehicle grade were 0% based on the measured grade and the acceleration determined in steps (a) and (b),
• d. determining the gross weight of the vehicle as a function of the acceleration .alpha. determined in step (c),
• e. determining the horse power required to maintain present vehicle speed, as a function of the gross vehicle weight, the present vehicle speed and present vehicle grade,
• f. predicting the engine speed at the completion of the shift as a function of the gross vehicle weight, vehicle grade, and torque interrupt time,
• g. determining the horse power available at the completion of a gear shift as a function of the predicted engine speed at the completion of the shift,
• h. initiating the shift only if the horse power available at completion of the shift is greater than the horse power required.

A method of controlling the initiation of a gear shift in an automated transmission of a vehicle comprising the :steps of:

• a. measuring the grade of the vehicle while the vehicle is moving,
• b. measuring the vehicle speed on the grade,
• c. determining the gross weight of the vehicle as a function of the data obtained in steps (a) and (b),
• d. determining the horse power required to maintain present vehicle speed, as a function of the gross vehicle weight, the present vehicle speed and present vehicle grade,
• e. predicting the vehicle speed at the completion of a shift as a function of the gross vehicle weight, vehicle grade, and torque interrupt time, and predicting the engine speed at the completion of a shift as a function of predicted vehicle speed,
• f. determining the horse power available at the completion of a gear shift as a function of the predicted engine speed at the completion of the shift,
• g. initiating a shift only if the horse power available at completion of the shift will be greater than the present required horse power.

A method of controlling the initiation of a gear shift in an automated transmission of a vehicle comprising the steps of:

• a. measuring the grade of the vehicle while the vehicle is moving,
• b. measuring the vehicle speed on the grade,
• c. determining the gross weight of the vehicle as a function of the data obtained in steps (a) and (b),
• d. determining the horse power required to maintain the present vehicle speed, as a function of the gross vehicle weight, the present vehicle speed and present vehicle grade,
• e. determining the horse power available at the completion of the shift as a function of the gross vehicle weight, the present vehicle grade, and torque interrupt time,
• f. initiating a shift at the present vehicle speed only if the horse power available at completion of the shift will be greater than the present required horse power.