Method for determining an axle load on a mechanically suspended vehicle

A method for determining an axle load on a mechanically suspended vehicle via a travel measurement device (9), an electronic control unit (10) and an algorithm stored in the control unit (10), the method comprising:

• first carrying out a test routine with respect to a mechanically suspended vehicle axle (4) by acquiring and evaluating a level signal of a travel measurement device (9) arranged on the vehicle axle (4), including the following steps:
• determining, in a loading operation of the vehicle, a loading curve (F_i) is determined from a plurality of measured values, the loading curve indicating a level measured with the travel measurement device (9), or another measured variable correlated with the level,
• determining, in an unloading operation of the vehicle, an unloading curve (F_u) from a plurality of measured values, the unloading curve indicating the level measured with the travel measurement device (9), or another measured variable correlated with the level,
• calculating, from values of the loading curve (F_i) and of the unloading curve (F_u) an averaged load-travel characteristic curve (F_m), and
• storing values of the averaged load-travel characteristic curve (F_m) in a non-volatile memory (10b) of the control unit (10), and
• after each start of the vehicle, and after a predefined lower traveling speed limit (v_min) that is greater than zero has been exceeded, cyclically repeating an axle load determination routine while the vehicle is moving at a vehicle speed that is greater than the lower traveling speed limit that is greater than zero, including the following steps:
• continuously determining, during a first predefined time period (Δt) defined by a given predetermined quantity of time, axle load values with the averaged load-travel characteristic curve (F_m), and calculating a first arithmetic axle load average value from the axle load values determined during the first predetermined time period (Δt),
• continuously determining, during a second predefined time period (Δt) defined by the given predetermined quantity of time, axle load values with the averaged load-travel characteristic curve (F_m), and calculating a second arithmetic axle load average value from the axle load values determined during the second predetermined time period (Δt), and
• displaying the first arithmetic axle load average value as a current axle load value, wherein the current axle load value remains valid until overwritten by the second arithmetic axle load average value;
• disregarding, in calculating the first and second arithmetic axle load average value, such axle load values that have been determined during cornering or during another driving maneuver causing lateral accelerations of the vehicle;
• identifying cornering or another driving maneuver of the vehicle that causes lateral accelerations of the vehicle by continuously acquiring and evaluating a lateral acceleration signal from a lateral acceleration sensor, and
• concluding that that the vehicle is cornering or making a driving maneuver causing lateral accelerations of the vehicle if the lateral acceleration signal represents an acceleration value that exceeds a predefined lateral acceleration limit value.