Vehicle load measuring apparatus and method

• US 5,877,454 A
• Filed: 06/25/1997
• Issued: 03/02/1999
• Est. Priority Date: 06/25/1996
• Status: Expired due to Fees

• Current Assignee: Mitsubishi FUSO Truck & Bus Corporation (Daimler Truck Holding AG)
• Original Assignee: Mitsubishi Jidosha Kogyo Kabushiki Kaisha
• Inventors: Makita, Takaaki, Uehara, Kazuyasu, Matsuura, Shinya
• Primary Examiner(s): Gibson, Randy W.
• Application Number:
  US08/882,116
• Time in Patent Office: 615 Days
• Field of Search: 177/1, 177/50, 177/136, 177/137, 177/141, 73/1.13
• US Class Current: 177/1
• CPC Class Codes: G01G 19/08 for incorporation in vehicles
• CPC Class Codes: G01G 23/48 Temperature-compensating arrangements G01G1/14, G01G1/42, G01G3/18 take precedence

Abstract

An apparatus for measuring a weight of load on a vehicle or a vehicle weight capable of easily compensating changes in load sensor outputs caused by temperature changes. When changes in load sensors outputs are so small such changes are determined as caused by temperature change, and a compensation process is made to output computed load values which were taken before occurrence of temperature change against the up-dated sensor detection outputs. On the other hand, when the changes are greater, the computed load values are up-dated to the up-date sensor detection outputs, thereby an accurate information of the change in the load is detected.

Claims

1. In a vehicle load information measuring apparatus, comprising:

load sensors mounted on members which receive a weight of a vehicle to detect the vehicle load information;

memory means for storing load detection signals detected by the at least one load sensor; and

load information control means for computing a load information by a predetermined computing equation based on load detection signals stored in the memory means and outputting a resulted value as a computed load value of the vehicle,

wherein the load information control means computes a first load information based on first load detection signals detected at a first predetermined point of time and stores said computed first load information, computes a second load information based on second load detection signals detected at a second point of time which is after the lapse of a predetermined time from the first point of time, computes at least one of changes between the first load detection signals and the second load detection signals and a change between the first load information and the second load information, and if said at least one of computed changes between the first and second load detection signals and the computed change between the first and second load information are below a first predetermined value, the computation made according to the predetermined computing equation is compensated so that the computed load value to be outputted at the second point of time is not up-dated to the second load information.

2. A vehicle load information measuring apparatus according to claim 1, wherein the load information control means maintains the first load information as the computed load value outputted at the second point of time.

3. A vehicle load information measuring apparatus according to claim 1, wherein the load information control means repeatedly computes at least one of the changes between the first and second load detection signals and the change between the first and second load information at every predetermined time interval.

4. A vehicle load information measuring apparatus according to claim 1, wherein the load sensors in plural are mounted on the vehicle, and the load information control means effects the compensation when the all the changes between the first and second load detection signals determined based on outputs from the load sensors are below the first predetermined value.

5. A vehicle load information measuring apparatus according to claim 1 further comprising:

temperature detection means for detecting the temperature around the load sensors, and

wherein, when a change of temperature between a first temperature detected at the first point of time and a second temperature detected at the second point of time is above a third predetermined value, the load information control means compares at least one of the changes between the first and second load detection signals and the change between the first and second load information with a second predetermined value, which is greater than the first predetermined value, instead of comparing with the first predetermined value.

6. A vehicle load information measuring apparatus according to claim 5, wherein the load sensors in plural are mounted on the vehicle, and the load information control means effects the compensation when all the the changes between the first and second load detection signals determined based on outputs from the load sensors are below the second predetermined value.

7. A vehicle load information measuring apparatus according to claim 3, wherein the predetermined computing equation is defined to compute the second load information based on the first load information and the changes between the first and second load detection signals.

8. A vehicle load information measuring apparatus according to claim 7, wherein the load information control means effects the compensation such that the changes between the first and second load detection signals become zero (0).

9. A vehicle load information measuring apparatus according to claim 8, wherein the load information control means up-dates the first load detection signals stored in the memory means to the second load detection signals (f_FR, f_FL, f_RR, f_RL).

10. A method of measuring a vehicle load, comprising:

detecting first load information indicative of a vehicle load at a first point of time by a load detection sensor;

storing said detected first load information;

detecting second load information indicative of the vehicle load at a second point of time after said first point of time by the load detection sensor;

calculting a difference between said first and second load information;

comparing said calculated difference with a first predetermined value;

replacing said stored detected first load information with said second load information when said calculated difference is smaller than the first predetermined value; and

calculating a vehicle load value based on said replaced second load information.

11. The method of claim 10, further comprising:

detecting first temperature information indicative of a temperature of said load detection sensor at the first point of time;

detecting second temperature information indicative of a temperature of said load detection sensor at the second point of time;

determining whether a difference between said first and second temperature information with a second predetermined value; and

executing said comparing step when said determined difference is smaller than said second predetermined value.

12. The method of claim 11, further comprising:

comparing said calculated difference with a third predetermined value in place of comparing said calculated difference with said first predetermined value when determined difference between said first and second temperature information is smaller than said second predetermined value.

13. The method of claim 10, further comprising:

calculating the vehicle load value based on the calculated difference between said first and second load information when said calculated difference between said first and second load information is greater than the first predetermined value.

14. The method of claim 10, further comprising:

calculating the vehicle load value based on the calculated difference between said first and second load information when said calculated difference between said first and second load information is greater than the third predetermined value.