Process and device for determining a vehicle's mass

• US 6,446,024 B1
• Filed: 03/05/1999
• Issued: 09/03/2002
• Est. Priority Date: 07/05/1997
• Status: Expired due to Term

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Leimbach, Klaus-Dieter, Veil, Hans, Hummel, Stefan
• Primary Examiner(s): Hilten, John S.
• Assistant Examiner(s): Pretlow, Demetrius R.
• Application Number:
  US09/254,351
• Time in Patent Office: 1,278 Days
• Field of Search: 702/141, 702/127, 702/142, 734/88, 735/03, 735/10, 735/140.1, 731/181, 731/46, 701/37, 701/38, 701/51, 701/67
• US Class Current: 702/141
• CPC Class Codes: B60T 2250/02 Vehicle mass
• CPC Class Codes: B60T 8/172 Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters B60T8/17551 takes precedence
• CPC Class Codes: B60W 2510/0657 Engine torque
• CPC Class Codes: B60W 2520/105 Longitudinal acceleration
• CPC Class Codes: B60W 40/13 Load or weight
• CPC Class Codes: F16H 2059/142 of driving resistance calculated from weight, slope, or the like
• CPC Class Codes: F16H 59/48 Inputs being a function of acceleration
• CPC Class Codes: F16H 59/52 dependent on the weight of the machine, e.g. change in weight resulting from passengers boarding a bus
• CPC Class Codes: G01G 19/086 wherein the vehicle mass is dynamically estimated

Abstract

A mass value is determined which represents the mass of a vehicle. The vehicle includes a drive unit and a clutch unit. By the disengagement of the clutch unit, the force flow between the drive unit and the vehicle wheels can be essentially interrupted. At least a first acceleration value is detected which represents the vehicle acceleration at a first time point. Furthermore, at least a first drive value is detected which represents the drive force or the drive torque of the drive unit at the first time point. At least a second acceleration value is detected which represents the vehicle acceleration at a second time point whereat the clutch unit is disengaged. A comparison then takes place of the detected second acceleration value with at least one pregivable threshold value. The determination of the mass value takes place at least in dependence upon the comparison and at least in dependence upon the detected first acceleration value and the detected first drive value.

Claims

1. A method for determining a mass value (M_tot) of a motor vehicle having a drive unit and a clutch unit, the mass value (M_mot) representing the mass of a motor vehicle such as a recreational or commercial motor vehicle, the force flow between the drive unit and the vehicle wheels being interruptible by disengaging the clutch unit, the method comprising the steps of:

detecting at least one first acceleration value (a₁) which represents the vehicle acceleration at a first time point at which the clutch unit is engaged;

detecting at least a first drive value (F_driv1) which represents the drive force or the drive torque of the drive unit at the first time point;

detecting at least a second acceleration value (a_open) which represents the vehicle acceleration at a second time point at which the clutch unit is disengaged;

comparing the detected second acceleration value (a_open) to at least one pregiven threshold value (Su, So);

detecting a roadway slope from the comparison of said second acceleration value (a_open) to said at least one pregiven threshold value (Su, So); and

,

determining the mass value (M_tot) at least in dependence upon said roadway slope and at least in dependence upon the detected first acceleration value (a₁) and the detected first drive value (f_driv1).

2. The method of claim 1, for the comparison, the method comprising the further step of determining whether the detected second acceleration value (a_open) lies within an interval (Su, So) with the acceleration values within said interval representing a travel on a plane roadway.

3. The method of claim 1, when determining that the detected second acceleration value (a_open) lies outside of the interval (Su, So), the method comprising the further step of determining the mass value (M_tot) in dependence upon the detected second acceleration value (a_open) in the sense of a correction caused by the roadway slope.

4. A method for determining a mass value (M_tot) of a motor vehicle having a drive unit and a clutch unit, the mass value (M_tot) representing the mass of a motor vehicle such as a recreational or commercial motor vehicle, the force flow between the drive unit and the vehicle wheels being interruptible by disengaging the clutch unit, the method comprising the steps of:

detecting at least one first acceleration value (a₁) which represents the vehicle acceleration at a first time point at which the clutch unit is engaged;

detecting at least a first drive value (F_driv1) which represents the drive force or the drive torque of the drive unit at the first time point;

detecting at least a second acceleration value (a_open) which represents the vehicle acceleration at a second time point at which the clutch unit is disengaged;

comparing the detected second acceleration value (a_open) to at least one pregiven threshold value (Su, So);

determining the mass value (M_tot) at least in dependence upon the comparison and at least in dependence upon the detected first acceleration value (a₁) and the detected first drive value (f_driv1); and

,

determining at least a first and a second running resistance value (M₁, M₂) at least in dependence upon two detected first acceleration values (a₁, a₂) and two detected first drive values (F_driv1, F_driv2).

5. The method of claim 4, the method comprising the further step of applying at least one of the determined running resistance values (M₁, M₂) to determine the mass value (M_tot) wherein the mean value is determined as mass value (M_tot) from at least two of the determined running resistance values (M₁, M₂).

6. The method of claim 4, the method comprising the further step of lowpass filtering the determined running resistance values (M₁, M₂).

7. The method of claim 4, wherein the determination of the mass value (M_tot) or for determining the running resistance values (M₁, M₂) a value (V_vehl), which represents the road speed, and/or a value (V_wheel), which represents the rotational speed of the wheels of the vehicle, is applied.

8. An arrangement for determining a mass value (M_tot), which represents the vehicle mass, for a vehicle having a drive unit and a clutch unit wherein the force flow between the drive unit and the vehicle wheels can be interrupted by disengaging the clutch unit, the arrangement comprising:

first detecting means for detecting at least a first acceleration value (a₁), which represents the vehicle acceleration at a first time point, when the clutch unit is engaged and for detecting at least a second acceleration value (a_open), which represents the vehicle acceleration at a second time point, when the clutch unit is disengaged;

second detecting means for detecting at least a first drive value (F_driv1), which represents the drive force or the drive torque of the drive unit at the first time point;

comparison means for comparing the detected second acceleration value (a_open) to at least one pregivable threshold value (Su, So);

means for detecting a roadway slope from the comparison of said second acceleration value (a_open) to said at least one pregivable threshold value (Su, So); and

,

means for determining the mass value (M_tot) at least in dependence upon said roadway slope and at least in dependence upon the detected first acceleration value (a₁) and the detected first drive value (F_driv1).

9. An arrangement for determining a mass value (M_tot), which represents the vehicle mass, for a vehicle having a drive unit and a clutch unit wherein the force flow between the drive unit and the vehicle wheels can be interrupted by disengaging the clutch unit, the arrangement comprising:

first detecting means for detecting at least a first acceleration value (a₁), which represents the vehicle acceleration at a first time point, when the clutch unit is engaged and for detecting at least a second acceleration value (a_open), which represents the vehicle acceleration at a second time point, when the clutch unit is disengaged;

second detecting means for detecting at least a first drive value (F_driv1), which represents the drive force or the drive torque of the drive unit at the first time point;

comparison means for comparing the detected second acceleration value (a_open) to at least one pregivable threshold value (Su, So);

means for determining the mass value (M_tot) at least in dependence upon the comparison and at least in dependence upon the detected first acceleration value (a₁) and the detected first drive value (F_driv1); and

,

wherein a determination is made by means of the comparison means as to whether the detected second acceleration value (a_open) lies within an interval (Su, So);

wherein acceleration values within this interval represent a drive on a roadway which is level;

wherein it is provided that, when it is determined that the detected second acceleration value (a_open) lies outside of the interval (Su, So), the mass value (M_tot) is determined in dependence upon the detected second acceleration value (a_open) in the sense of a correction caused by the slope of the roadway.