Method and device for determining the mass of a vehicle

The method for determining a mass of a vehicle driven by at least one prime mover having a power shiftable stepped variable speed transmission with several gear steps which, on one side, are connectable to said prime mover via a starting element and, on another side, is operatively connected with input gears of the vehicle, the method comprising the steps of:

• performing at least first and second measurements offset in time during a measuring period by which at least one traction variable produced by the prime mover indicating traction acting upon the input gears of the vehicle in driving direction of movement and at least one movement variable indicating movement of the vehicle are respectively determined, and wherein a first traction acting upon the input gears during the first measurement is similar in value to a second traction acting upon the input gears during the second measurement;
• and
• calculating an actual mass of the vehicle from the variables determined from both the first and second measurements offset in time, the first measurement comprises a first data collection period, the second measurement comprises a second data collection period, and a duration of the first and second data collection periods is longer than a minimum duration, the traction variable corresponds to a timed integral of the traction acting during the respective data collection period and the movement variable corresponds to a change in speed of the vehicle occurring during the respective data collection period, and the first measurement taking place immediately before a gear shift and the second measurement taking place immediately after a gear shift.

A device for determining a mass of a vehicle driven by at least one prime mover having a power shiftable stepped variable speed transmission with several gear steps which, on one side, are connectable to said prime mover via a power shiftable clutch serving as a starting element and, on another side, is operatively connected with input gears of the vehicle, comprising:

• an evaluation section for calculating an actual mass of the vehicle from variables determined by the first and second measurements offset in time, including
• a first measuring means for determining a traction transmitted by the prime mover to the input gears, and
• a second measuring means for determining the vehicle speed and determining at least one movement variable indicating movement of the vehicle,
• the first measuring means performing measurements during a measuring period including a first data collection period and a second data collection period wherein the measurements determine a traction variable, wherein
• the first data collection period is a fraction phase when the clutch is engaged and traction is transmitted to the input gears, and
• the second data collection period is a traction-free phase when the clutch is disengaged to facilitate a gear shift of the stepped variable speed transmission.