On-board scale with remote sensor processing

• US 5,780,782 A
• Filed: 11/17/1997
• Issued: 07/14/1998
• Est. Priority Date: 02/15/1995
• Status: Expired due to Term

• Current Assignee: Hi-Tech Transport Electronics, Inc.
• Original Assignee: Hi-Tech Transport Electronics, Inc.
• Inventors: O'Dea, James O.
• Primary Examiner(s): Gellner, Michael L.
• Assistant Examiner(s): Gibson, Randy W.
• Application Number:
  US08/971,759
• Time in Patent Office: 239 Days
• Field of Search: 177/136, 177/137, 177/138, 177/139, 177/141, 177/50, 73/1.13
• US Class Current: 177/136
• CPC Class Codes: G01G 19/08 for incorporation in vehicles
• CPC Class Codes: G01G 23/01 Testing or calibrating of weighing apparatus

Abstract

An on-board weighing system employs a master unit, and one or more remote units to which weight sensors are connected. Calibration information for each weight sensor is stored in the remote unit to which it is connected. Analog weight related signals generated by the weight sensors also are converted by the remote units to digital sensor values. The remote units are connectable by a communications network with the master unit such that the master unit can read the digital sensor value and calibration information of each weight sensor for processing to yield vehicle weight. The on-board weighing system facilitates trailer swapping by automatically recording and tracking calibration information for the weight sensors in the remote units which together are mounted on the trailers that are swapped.

Claims

1. An on-board weighing apparatus for a vehicle having at least one weight-supporting suspension group, comprising:

at least one sensor being mountable on the vehicle and associated in a one-to-one relationship to the at least one suspension group, each of the at least one sensor being operative to generate a signal related to a weight supported on its respective suspension group;

at least one remote sensor processing unit mountable on the vehicle and associated in a one-to-one relationship to the at least one sensor, each of the remote sensor processing unit being operative to store signal-to-weight conversion parameters related to its respective sensor, the signal-to-weight conversion parameters characterizing a conversion of the weight related signal to a weight of the vehicle at the respective suspension group associated with the at least one sensor;

a host processing unit mounted on the vehicle and in communication with the at least one remote sensor processing unit, the host processing unit being operative to receive the signal generated by each of the at least one sensor, to read the signal-to-weight conversion parameters from each of the at least one remote sensor processing unit, and to generate weight data for each of the at least one suspension group as a function of the signal-to-weight conversion parameters and the signal from its respective sensor and remote sensor processing unit; and

a display for providing a visual indication of the weight data.

2. The on-board weighing apparatus of claim 1 wherein the signal-to-weight conversion parameters stored by each of the at least one remote sensor processing unit comprises a signal-to-weight ratio value and an unsprung weight offset value, the unsprung weight offset value characterizing the unsprung weight of the vehicle at the respective suspension group and the signal-to-weight ratio value characterizing a relationship of the signal generated by the respective sensor to the vehicle weight at the suspension group.

3. The on-board weighing apparatus of claim 1 wherein each of the at least one remote sensor processing unit comprises an analog to digital converter coupled to its respective sensor for converting the signal of the respective sensor to a digital sensor value, the host processing unit being operative to read the digital sensor value whereby the host processing unit receives the signal from the respective sensor.

4. The on-board weighing apparatus of claim 1 comprising:

a polling network connecting the at least one remote sensor processing unit and the host processing unit; and

the host processing unit being operative to poll each of the at least one remote sensor processing unit to read the signal-to-weight conversion parameters from the at least one remote sensor processing unit.

5. The on-board weighing apparatus of claim 4 wherein the polling network comprises:

a power line cable connecting to the host processing unit and the at least one remote sensor processing unit; and

a plurality of power line modems connecting to the power line cable, one in each of the host processing unit and the at least one remote sensor processing unit.

6. The on-board weighing apparatus of claim 4 wherein each of the at least one remote sensor processing unit comprises an analog to digital converter coupled to its respective sensor for converting the signal of the respective sensor to a digital sensor value, the host processing unit being operative to poll each of the at least one remote sensor processing unit to read the digital sensor value whereby the host processing unit receives the signal generated by the respective sensor.

7. The on-board weighing apparatus of claim 4 wherein each of the at least one remote sensor processing unit has a polling address selector for use by an operator of the apparatus to select a polling address for each of the at least one remote sensor processing unit whereby the at least one remote sensor processing unit is individually identifiable by the host processing unit on the polling network.

8. The on-board weighing apparatus of claim 1 comprising:

a plurality of data entry keys for use by an operator of the apparatus to enter data for a plurality of weights supported on the at least one suspension group into the host processing unit; and

the host processing unit being operative to generate the signal-to-weight conversion parameters related to each of the at least one sensor based on the signal generated by said sensor at the weights and on the data, the host processing unit being operative to store the signal-to-weight conversion parameters in the sensor'"'"'s respective at least one remote sensor processing unit.

9. The on-board weighing apparatus of claim 8 comprising:

the host processing unit being operative, for each of the at least one sensor, to receive data entered with the data entry keys for a first weight and a second weight supported on the respective suspension group of the sensor, to read the signal generated by the sensor at the first and second weights, to generate signal-to-weight conversion parameters as a function of the entered data and the signal for the first and second weights, and to store the signal-to-weight conversion parameters into the respective remote sensor processing unit of the sensor.

10. A method of measuring vehicle weight, comprising:

generating a signal related to a vehicle weight with a weight transducer;

storing signal-to-weight conversion parameters for the weight transducer in a remote sensor processing unit connected to the weight transducer, the signal-to-weight conversion parameters characterizing a conversion of the generated signal to the vehicle weight;

converting the signal with the remote sensor processing unit to form a digital sensor value;

interconnecting the remote sensor processing unit and a master processing unit in a communications network;

transmitting the signal-to-weight conversion parameters and digital sensor value from the remote sensor processing unit to the master processing unit;

processing the signal-to-weight conversion parameters and digital sensor value with the master processing unit to determine the vehicle weight; and

visually indicating the vehicle weight.

11. The method of claim 10, comprising:

polling the remote sensor processing unit by the master processing unit; and

transmitting the signal-to-weight conversion parameters and digital sensor value from the remote sensor processing unit to the master processing unit in response to said polling.

12. The method of claim 10, comprising:

interconnecting a plurality of remote sensor processing units with the master processing unit in the communications network;

storing signal-to-weight conversion parameters in the remote sensor processing units for a plurality of weight transducers respectively connected one-to-one to the remote processing units;

generating a plurality of signals related to portions of a vehicle weight with the weight transducers;

converting the signals with the remote sensor processing units to a plurality of digital sensor values;

transmitting the signal-to-weight conversion parameters and digital sensor value for each of the weight transducers from its respective remote sensor processing unit to the master processing unit;

processing the signal-to-weight conversion parameters and digital sensor value for each of the weight transducers with the master processing unit to determine the portions of the vehicle weight; and

summing the portions of the vehicle weight with the master processing unit to yield the vehicle weight.

13. The method of claim 12, comprising:

individually polling one of the remote sensor processing units by the master processing unit;

transmitting the signal-to-weight conversion parameters and digital sensor value from said remote sensor processing unit to the master processing unit in response to said polling;

processing the signal-to-weight conversion parameters and digital sensor value transmitted from said remote sensor processing unit with the master processing unit to determine a respective portion of the vehicle weight; and

visually indicating the respective portion of the vehicle weight.

14. An on-board vehicle scale for vehicles having interchangeable trailers, comprising:

a master processor mountable on a vehicle;

a weight transducer mountable on a trailer for generating a signal related to a weight supported on a suspension group of the trailer;

a remote sensor processor mountable on the trailer and connected to the weight transducer for receiving the signal;

a non-volatile memory in the remote sensor processor for storing signal-to-weight conversion parameters characterizing a conversion from the signal generated by the weight transducer to a weight of the vehicle at the suspension group;

a communications network for interconnecting the master processor and the remote sensor processor; and

the master processor being operative to read the signal-to-weight conversion parameters and the signal from the remote sensor processor, and to process the signal using the signal-to-weight conversion parameters to determine the weight.

15. The on-board vehicle scale of claim 14, comprising:

the weight transducer producing an analog signal related to the weight supported on the suspension group of the trailer;

an analog to digital converter in the remote sensor processor for digitizing the analog signal; and

the master processor being operative to read the digitized analog signal from the remote sensor processor.

16. The on-board vehicle scale of claim 14, comprising:

a display coupled to the master processor for visually indicating the weight.

17. The on-board vehicle scale of claim 14 wherein the communications network comprises:

a power line;

a first modem coupling the remote sensor processor to the power line; and

a second power line modem coupling the master processor to the power whereby the master processor communicates with the remote sensor processor.

18. The on-board vehicle scale of claim 14, comprising:

a first weight transducer connected to a first remote sensor processor, both being mounted on a first trailer, the first remote sensor processor being connectable to the communications network when the first trailer is attached to the vehicle; and

a second weight transducer connected to a second remote sensor processor, both being mounted on a second trailer, the second remote sensor processor being connectable to the communications network when the second trailer is attached to the vehicle;

the master processor being operative to read the signal-to-weight conversion parameters and the signal from the respective remote sensor processor connected to the communications network, and to process said signal using said signal-to-weight conversion parameters to determine a weight supported on a suspension group of a respective one of the first and second trailers which is attached to the vehicle, whereby the weight can be measured without recalibration when switching between the first and second trailers.

19. The on-board vehicle scale of claim 14, comprising:

a plurality of weight transducers, each for generating a signal relating to a weight supported on a suspension group of the vehicle;

a plurality of remote sensor processors connected one-to-one with the weight transducers and each being operative to store signal-to-weight conversion parameters related to its respective connected weight transducer;

the communications network interconnecting the remote sensor processors with the master processor;

the master processor being operative to read the signal and signal-to-weight conversion parameters for each weight transducer from its respective remote sensor processor, and to process the signals using the signal-to-weight conversion parameters to determine a weight of the vehicle.

20. The on-board vehicle scale of claim 14 wherein the non-volatile memory is modifiable after installation of the remote sensor processor on the vehicle, and the master processor is further operative to derive the signal-to-weight conversion parameters from input reference weights and store the signal-to-weight conversion parameters into the non-volatile memory.