Tension Monitoring Arrangement and Method

• US 20080215258A1
• Filed: 01/22/2008
• Published: 09/04/2008
• Est. Priority Date: 05/24/2002
• Status: Active Grant

• Current Assignee: Merlin Technologies Incorporated
• Original Assignee: Merlin Technologies Incorporated
• Inventors: Mercer, John E., Zeller, Rudolf, Chau, Albert W., Tsang, Charles Yu Yat
• Granted Patent: US 7,578,201 B2
• Time in Patent Office: Days
• US Class Current: 702/43
• CPC Class Codes: B66C 13/16 Applications of indicating, registering, or weighing devices in crane hooks B66C1/40; in safety gear B66C15/00; weighing-apparatus G01G; remote indicating in general G08
• CPC Class Codes: B66C 23/905 electrical
• CPC Class Codes: B66D 1/54 Safety gear
• CPC Class Codes: G01L 1/26 Auxiliary measures taken, or devices used, in connection with the measurement of force, e.g. for preventing influence of transverse components of force, for preventing overload
• CPC Class Codes: G01L 5/10 using electrical means
• CPC Class Codes: G01L 5/103 using sensors fixed at one end of the flexible member

Abstract

Tension monitoring is described using a sensor which may exhibit an offset for which compensation may be provided to produce a zero voltage amplified output or to increase dynamic range. An arrangement determines whether a power reset is responsive to a battery bounce such that an initially-measured system start-up parameter can be retained. The start-up parameter is automatically saved at start-up if the power reset is responsive to a start-up from a shut-down condition. The start-up parameter may be a zero tension amplified output responsive to the sensor offset at zero tension. Protection of a tension data set is provided such that no opportunity for altering the data set is presented prior to transfer of the data set. A housing configuration forms part of an electrical power circuit for providing electrical power to an electronics package from a battery.

Claims

1. In a system for installing an underground utility by retraction that is applied to a leading end of the utility to draw the utility through the ground such that the utility is subjected to a tension force, said system including an inground tension monitoring arrangement having a processing arrangement which receives electrical power from a power supply in a way which may subject the processing arrangement to a loss of power that is temporary during system operation, as well as a shut-down loss of power condition, either of which causes the processing arrangement to reset, an apparatus comprising:

a first arrangement for producing an output signal that is responsive to a time duration of the loss of power; and

a second arrangement, cooperating with said processing arrangement, for using said output signal to establish whether a particular reset is responsive to a power supply bounce condition during operation.

2. The apparatus of claim 1 wherein said processing arrangement is configured for saving at least one system start-up parameter at an initial system start-up and wherein said processing arrangement is further configured for re-entering a run mode responsive to establishing that the particular reset is responsive to said power supply bounce condition while retaining the system start-up parameter.

3. The apparatus of claim 2 wherein said system includes a sensing arrangement that produces a sensor signal that is characterized by a nonzero offset value at a tension force of zero and said processing arrangement saves a nonzero amplified offset voltage, that is produced responsive to said nonzero offset value, as said system start-up parameter.

4. The apparatus of claim 1 wherein said processing arrangement is configured for saving at least one system start-up parameter at an initial system start-up and wherein said processing arrangement is further configured for entering a start-up mode responsive to establishing that the particular reset is not responsive to said power supply bounce condition in which said system start-up parameter is replaced with a new system start-up parameter.

5. The apparatus of claim 1 wherein said processing arrangement is configured for determining that any measured value of said output signal, which measured value is responsive to said particular reset, above a predetermined threshold value indicates said power supply bounce condition during operation.

6. The apparatus of claim 1 wherein said first arrangement includes means for producing said output signal using a time constant.

7. In a system for installing an underground utility by retraction that is applied to a leading end of the utility to draw the utility through the ground such that the utility is subjected to a tension force, said system including an inground tension monitoring arrangement having a processing arrangement which receives electrical power from a power supply in a way which may subject the processing arrangement to a loss of power that is temporary during system operation, as well as a shut-down loss of power condition, either of which causes the processing arrangement to reset, a method comprising the steps of:

configuring a first arrangement for producing an output signal that is responsive to a time duration of the loss of power; and

using said output signal to establish whether a particular reset is responsive to a power supply bounce condition during operation.

8. The method of claim 7 wherein said processing arrangement is configured for saving at least one system start-up parameter at an initial system start-up and including the step of configuring said system to re-enter a run mode responsive to establishing that the particular reset is responsive to said power supply bounce condition while retaining the system start-up parameter.

9. The method of claim 7 wherein said processing arrangement is configured for saving at least one system start-up parameter at an initial system start-up and including the step of configuring said system to enter a start-up mode, after establishing that the particular reset is not responsive to said power supply bounce condition, in which said system start-up parameter is replaced with a new system start-up parameter.

10. The method of claim 9 wherein said system includes a sensing arrangement that produces a sensor signal that is characterized by a nonzero offset value at a tension force of zero and said method includes the step of saving a nonzero amplified offset voltage, that is produced responsive to said nonzero offset value, as said system start-up parameter.

11. The method of claim 7 wherein the step of using the output signal includes the step of comparing a measured value of said output signal, which measured value is responsive to said particular reset, to a predetermined threshold value such that any value of the measured value that is above the predetermined threshold value is responsive to a power supply bounce condition.

12. The method of claim 7 including the step of using a time constant that is defined by said first arrangement in producing said output signal.

13. In a system for installing an underground utility by retraction that is applied to a leading end of the utility to draw the utility through the ground such that the utility is subjected to a tension force, an apparatus comprising:

a sensing arrangement for inground sensing of the tension force that is applied to the leading end of the utility to produce a sensor signal such that a zero tension sensed value may be offset from a zero voltage;

an amplifier arrangement for using the sensor signal to generate an amplified output signal such that a zero tension amplified output is produced responsive to said zero tension sensed value; and

processing means for measuring said amplified output signal at least in a way which measures said zero tension amplified output responsive to powering on said sensing arrangement and said amplifier arrangement, and for saving the zero tension amplified output.

14. The apparatus of claim 13 wherein said processing means is configured for issuing a ready for calibration signal after saving said zero tension amplified output and said apparatus includes transceiver means for transmitting said ready for calibration signal to an above ground location.

15. The apparatus of claim 14 wherein said transceiver means is configured to listen for a calibration signal from the above ground location for a predetermined time interval, responsive to said ready for calibration signal.

16. The apparatus of claim 15 wherein said processing means is configured for at least one of entering a run mode, if said calibration signal is not received during the predetermined time interval, in which the saved zero tension amplified output is used by the processing means to determine at least one compensated tension measurement and entering a calibration procedure, if said calibration signal is received during the predetermined time interval.

17. The apparatus of claim 16 wherein said processing arrangement is configured for producing a digital drive signal responsive to said amplified output signal and said apparatus includes a compensation arrangement for applying a compensation voltage to said amplifier arrangement for shifting said amplified output signal responsive to the digital drive signal and said processing arrangement is further configured for repetitively adjusting said digital drive signal to obtain a target value of said amplified output signal at zero tension on the utility.

18. The apparatus of claim 17 wherein said processing arrangement is configured for saving an adjusted digital drive signal value which produces said target value of the amplified output signal.

19. The apparatus of claim 18 wherein said processing arrangement is further configured for (i) measuring said amplified output signal responsive to an application of at least one nonzero tension that is applied to the leading end of the utility, (ii) determining a calibration constant using the measured amplified output signal responsive to the nonzero tension and the target value of the amplified output signal, and (iii) issuing a calibration complete signal to the above ground location.

20. In a system for installing an underground utility by retraction that is applied to a leading end of the utility to draw the utility through the ground such that the utility is subjected to a tension force, a method comprising the steps of:

providing a sensing arrangement for inground sensing of the tension force that is applied to the leading end of the utility to produce a sensor signal such that a zero tension sensed value may be offset from a zero voltage;

using the sensor signal in an amplifier arrangement to generate an amplified output signal such that a zero tension amplified output is produced responsive to said zero tension sensed value;

measuring said amplified output signal with processing means at least in a way which measures said zero tension amplified output responsive to powering on said sensing arrangement and said amplifier arrangement; and

saving the zero tension amplified output with said processing means.

21. The method of claim 20 including the step of issuing a ready for calibration signal from said processing means, after saving said zero tension amplified output, and transmitting said ready for calibration signal, using transceiver means, to an above ground location.

22. The method of claim 21 including the step of listening for a calibration signal from the above ground location using the transceiver means in cooperation with the processing means for a predetermined time interval, responsive to said ready for calibration signal.

23. The method of claim 22 including the step of configuring said processing means for at least one of entering a run mode, if said calibration signal is not received during the predetermined time interval, in which the saved zero tension amplified output is used by the processing means to determine at least one compensated tension measurement and entering a calibration procedure, if said calibration signal is received during the predetermined time interval.

24. The method of claim 23 including the steps of using said processing arrangement to produce a digital drive signal responsive to said amplified output signal and applying a compensation voltage, with a compensation arrangement, to said amplifier arrangement for shifting said amplified output signal responsive to the digital drive signal and, thereafter, repetitively adjusting said digital drive signal with the processing arrangement to obtain a target value of said amplified output signal at zero tension on the utility.

25. The method of claim 24 including the step of saving an adjusted digital drive signal value, using the processing arrangement, which produces said target value of the amplified output signal.

26. The method of claim 25 including the steps of using the processing arrangement for (i) measuring said amplified output signal responsive to an application of at least one nonzero tension that is applied to the leading end of the utility, (ii) determining a calibration constant using the measured amplified output signal responsive to the nonzero tension and the target value of the amplified output signal, and (iii) issuing a calibration complete signal to the above ground location.