Claims:We Claim:
1. A method for determining if a vehicle is overloaded by a vehicle load monitoring unit, said method comprising:
determining ambient temperature 10 of the air around the vehicle by means of a temperature sensor;
determining a position of an accelerator pedal 20 of the vehicle by means of an accelerator pedal sensor;
determining a speed of the vehicle 30 by means of a vehicle speed sensor;
determining an antilock braking system state of the brake 40 by means of the vehicle load monitoring unit;
determining a theoretical displacement travelled by the vehicle 50 based on the determined ambient temperature, determined position of the accelerator pedal of the vehicle, determined speed of the vehicle, and the determined ABS state of the brake;
determining an actual displacement travelled by the vehicle 60 based on an output of current vehicle speed and time for deceleration of the vehicle from the current vehicle speed to a stationary position of the vehicle; and
determining that an actual load acting on the vehicle 70 is greater than a threshold load acting on the vehicle if the actual displacement travelled by the vehicle is greater than the theoretical displacement travelled by the vehicle.
, Description:Field of the invention
[0001] This invention relates to a method for determining if a vehicle is overloaded.

Background of the invention
[0002] DE 19747527 A1 describes a brake system for a vehicle that has each wheel fitted with sensors to monitor the brake effect as well as the wheel displacement, Etc. A central control unit processes the sensor data to determine a variety of conditions including the effectiveness of each wheel brake, brake wear, vehicle loading, vehicle dynamics/stability and to operate ABS, ASR, Etc. The control system can be applied to all types of brakes including electrically operated brakes.

Brief description of the accompanying drawing
[0003] Figure 1 illustrates a block diagram of a method for determining if a vehicle is overloaded.

Detailed description of the invention
[0004] Figure 1 illustrates a block diagram of a method for determining if a vehicle is overloaded. The method comprises determining the ambient temperature of the surrounding around the vehicle 10 by means of a temperature sensor, determining a position of an accelerator pedal of the vehicle 20 by means of an accelerator pedal sensor, determining a speed of the vehicle 30 by means of a vehicle speed sensor, determining an ABS state of the brake 40 by means of the vehicle load monitoring unit. The method further comprises determining a theoretical displacement travelled by the vehicle 50 based on the determined ambient temperature, determined position of the accelerator pedal of the vehicle, determined speed of the vehicle, and the determined ABS state of the brake, determining an actual displacement travelled by the vehicle 60 based on an output of current vehicle speed and time for deceleration of the vehicle from the current vehicle speed to zero vehicle speed, and determining that an actual load acting on the vehicle 70 is greater than a threshold load acting on the vehicle if the actual displacement travelled by the vehicle is greater than the theoretical displacement travelled by the vehicle.
[0005] The method comprises a temperature sensor that is coupled to a vehicle and senses the ambient temperature around the vehicle. More specifically, the temperature sensor may be any type of temperature sensor known in the art that is coupled to any portion of the vehicle and senses the ambient temperature around the vehicle. The sensed temperature signal is transmitted to the load monitoring unit. The temperature of the ambient surroundings around the vehicle is determined by the load monitoring unit. In addition, an accelerator pedal sensor that is coupled to the accelerator pedal senses a position of the accelerator pedal. If the accelerator pedal is in a depressed position, the load monitoring unit will determine that the vehicle is in an accelerating state from the acceleration pedal sensor and will not record the measurements from any of the other sensors. If the accelerator pedal is not in the depressed position, the load monitoring unit will determine that the vehicle is not in the accelerating state and will therefore record the measurements from the other sensors. In addition, the ambient surface conditions of the surrounding around the vehicle such as rain, the slope of the terrain and the like are sensed and used to determine the theoretical displacement that can be travelled by the vehicle based on the conditions of temperature of the ambient surroundings around the vehicle, the accelerating state of the vehicle, an instantaneous speed of the vehicle, and the ABS state of the vehicle.
[0006] The vehicle speed sensor that is mounted on the vehicle determines an instantaneous speed of the vehicle. Therefore, the instant at which the vehicle speed is required to be recorded is obtained by means of the load monitoring unit. Therein, the vehicle speed sensor transmits a signal that is indicative of the instantaneous speed of the vehicle to the load monitoring unit. Finally, the ABS state of the vehicle is communicated by means of the ABS sensor to the load monitoring unit. Once the load monitoring unit determines that the ABS sensor is activated, it acquires data from the vehicle speed sensor, the accelerator pedal sensor, and the temperature sensor on the instantaneous value of the vehicle speed, the accelerator pedal position, and the ambient temperature surrounding the vehicle. Based on the inputs from the vehicle speed sensor, the ABS state of the vehicle, accelerator pedal sensor, and the temperature sensor, a theoretical displacement that can potentially be travelled by the vehicle is determined by the load monitoring unit.
[0007] Therein, based on an output of current vehicle speed and time for deceleration of the vehicle from the current vehicle speed to zero vehicle speed, an actual displacement travelled by the vehicle is determined. If the actual displacement travelled by the vehicle is greater than the theoretical displacement travelled by the vehicle, it is determined by the load monitoring unit that the actual load acting on the vehicle is greater than a maximum rated threshold load that can act on the vehicle.
[0008] It must be understood that the embodiments explained above are only illustrative and do not limit the scope of the disclosure. Many modifications in the embodiments with regard to leverage and dimensions of various components are envisaged and form a part of this invention. The scope of the invention is only limited by the claims.