Inclination sensor

• US 5,731,761 A
• Filed: 12/06/1996
• Issued: 03/24/1998
• Est. Priority Date: 12/06/1996
• Status: Expired due to Fees

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Sychra, Robert R.
• Primary Examiner(s): SWANN III, GLEN R
• Application Number:
  US08/760,885
• Time in Patent Office: 473 Days
• Field of Search: 340/689, 340/501, 33/366, 33/377, 364/559
• US Class Current: 340/689
• CPC Class Codes: G01C 9/06 Electric or photoelectric indication or reading means

Abstract

An inclination sensor is disclosed. The sensor includes two temperature controlled inclination devices that are mounted orthogonal to each other. The inclination devices include an oven, a resistive element attached to the oven, an inclination transducer mounted in the oven and a thermistor being mounted to the oven. The thermistor produces a signal representative of the actual temperature of the oven. A microprocessor receives the actual temperature signal of each inclination device and produce heating signals to energize the corresponding resistive elements to control the temperature of the respective ovens to a desired temperature.

Claims

1. An inclination sensor, comprising:

two temperature controlled inclination devices being mounted orthogonal to each other in a horizontal plane, each inclination device, including;

an oven;

a resistive element being attached to the oven to provide heating energy thereto;

an inclination transducer being mounted in the oven; and

a thermistor being mounted to the oven and adapted to produce a signal representative of the actual temperature of the oven;

the inclination sensor further including;

a first microprocessor adapted to receive the actual temperature signal of each inclination device and produce heating signals to energize the corresponding resistive elements to control the temperature of the respective ovens to a desired temperature;

an oscillator being adapted to produce a signal to energize the inclination transducer; and

wherein the first microprocessor receives signals from the energized inclination transducers that represent the inclination of the respective transducers.

2. An inclination sensor, as set forth in claim 1, wherein the first microprocessor determines a desired temperature of the oven and produces a signal representative thereof, compares the desired temperature signal magnitude to the actual temperature signal magnitude, and produces an error signal indicative of the difference between the desired and actual temperature signal magnitude.

3. An inclination sensor, as set forth in claim 2, wherein the first microprocessor multiplies the error signal by a gain value and responsively produces the heating signal with a pulse width modulation form.

4. An inclination sensor, as set forth in claim 3, including a transistor being connected to the first microprocessor and adapted to receive the heating signal and responsively energize the resistive element in response to the conduction pulse width of the heating signal.

5. An inclination sensor, as set forth in claim 1, wherein the inclination transducers each include a three terminal device having one input terminal driven with the oscillator signal and the other two terminals providing output signals whose magnitude changes differentially with the inclination of the transducer.

6. An inclination sensor, as set forth in claim 5, wherein each temperature controlled inclination device includes an analog to digital converter mounted in the oven and connected to the output terminals of a respective inclination transducer, the analog to digital converter being adapted to measure the difference between the output signal magnitudes of the respective inclination transducer and produce digital signals representative of the inclination of the transducer.

7. An inclination sensor, as set forth in claim 6, wherein the first microprocessor receives the digital signals from the analog to digital converter and produces a slope signal representative of the inclination of one of the transducers and a pitch signal representative of the inclination of the other transducer.

8. An inclination sensor, as set forth in claim 7, including a second microprocessor connected to the first microprocessor, the second microprocessor receives the slope and pitch signal, determines the inclination of the respective transducers, and produces respective display signals.

9. An inclination sensor, as set forth in claim 8, including a display device being connected to the second microprocessor, the display device receiving the display signals and displaying the slope and pitch of the inclination sensor.

10. An inclination sensor, as set forth in claim 9, wherein the resistive element includes two power resisters that heat the oven.

11. An inclination sensor, as set forth in claim 10, wherein the inclination transducer is a fluid type device containing an electrolytic solution.