WO2014131318A1

WO2014131318A1 - Intelligent analogue weighing sensor and self-diagnosing method thereof

Info

Publication number: WO2014131318A1
Application number: PCT/CN2014/070346
Authority: WO
Inventors: 高酩; 张颖; 刘宏伟; 周亮; 朱志坚
Original assignee: 梅特勒-托利多(常州)精密仪器有限公司; 梅特勒-托利多(常州)测量技术有限公司; 梅特勒-托利多(常州)称重设备系统有限公司
Priority date: 2013-02-26
Filing date: 2014-01-09
Publication date: 2014-09-04
Also published as: CN104006868B; CN104006868A

Abstract

Provided is an intelligent analogue weighing sensor comprising an elastic body (101), a resistance strain gage (103), a bridge circuit board (102) and a cable joint (104), which are fixed on the elastic body (101), and a cable (105), one end of which is connected with the cable joint (104). The intelligent analogue weighing sensor further comprises a self-diagnosis circuit board (106) connected with the bridge circuit board (102) via the cable joint (104) and the cable (105), a signal divider (107) connected with the other end of the cable (105), and a sensor joint (108) and a communication joint (109) connected with the signal divider (107) respectively, wherein the signal divider (107) divides the signal from the self-diagnosis circuit board (106) into sensor signal transmitted to the sensor signal joint (108) and diagnosis signal transmitted to the communication joint (109). Also provided is a self-diagnosis method using the above intelligent analogue weighing sensor.

Description

Intelligent analog load cell and self-diagnosis method thereof

The invention relates to an intelligent analog weighing sensor and a self-diagnosis method thereof, in particular to an intelligent analog weighing sensor with self-diagnosis function, capable of alarming and recording errors and a self-diagnosis method thereof. Background technique

The traditional analog load cell consists of an elastomer, a strain gauge attached to the elastomer, a bridge circuit, a cable connector and a cable. When the elastic body is deformed by an external force, the resistance strain gauge fixed on the elastic body is also deformed at the same time, resulting in a change in resistance value, and the weight signal is converted into an analog electric signal by the bridge circuit, and finally output through the cable. Since there is only one electrical signal cable connector, when the sensor fails, the sensor must be repaired using an external device such as a multimeter. In the case of multiple sensor networks, when one of them fails, each sensor needs to be tested to find the faulty sensor, which brings great inconvenience to the maintenance work. If the sensor is installed or used improperly, it will cause damage to the sensor and shorten the life of the sensor. Summary of the invention

The invention aims to provide an intelligent analog load cell and a self-diagnosis method thereof. The invention can realize the self-diagnosis of the fault without affecting the performance of the sensor, and can report and record the wrong use of the sensor, thereby greatly improving the maintenance efficiency and ensuring the service life of the sensor.

Specifically, according to an aspect of the present invention, an intelligent analog load cell is provided, comprising an elastic body, a resistance stress piece fixed to the elastic body, a bridge circuit board and a cable joint, and one end connected to the The cable of the cable connector, wherein the smart analog load cell further comprises: a self-diagnostic circuit board via which the signal is connected to the bridge circuit board via the cable connector; a signal splitter, The other end of the cable is connected; and a sensor signal connector and a communication connector are respectively connected to the signal splitter, wherein the signal splitter splits the signal from the self-diagnostic circuit board into the sensor signal connector Sensor signal and diagnostic signal transmitted to the communication connector.

Preferably, in the above intelligent analog load cell, the self-diagnostic circuit board is the same as the signal The splitter is formed as a whole.

Preferably, in the above intelligent analog load cell, the self-diagnostic circuit board is disposed on the elastic body.

Preferably, in the above intelligent analog load cell, the self-diagnostic circuit board includes: a main controller, a preset resistor, and an analog-to-digital conversion circuit, a voltage measuring circuit, and a temperature connected to the main controller signal. a measurement circuit, a data storage circuit, and a communication circuit, wherein the analog to digital conversion circuit is connected between an output end of the group bridge circuit board and the main controller; wherein the voltage measurement circuit measures the resistance stress The excitation signal of the slice; wherein the temperature measurement circuit measures an ambient temperature; wherein the data storage circuit stores a set of standard parameter values of the intelligent analog load cell.

Preferably, in the above intelligent analog load cell, the self-diagnostic circuit board further includes an angle measuring circuit for measuring the mounting angle of the intelligent analog load cell.

Further, according to another aspect of the present invention, there is provided a self-diagnostic method using the intelligent analog load cell as described above, the method comprising: removing a weight on the smart analog load cell; Converting the zero-point analog signal of the resistance stress piece to a zero-point digital signal to the main controller; the main controller is configured to store the zero-point digital signal in the data storage circuit Comparing a zero point output value of a set of standard parameter values to determine whether there is a zero point error; the main controller causes an analog signal of the resistance stress piece to flow through a preset resistor to measure a full scale state a full-scale digital signal; the main controller compares the full-scale digital signal with a full-scale output value of the set of standard parameter values stored in the data storage circuit to determine whether there is a full-scale overshoot And the main controller outputs the result of the above determination through the communication circuit.

Preferably, in the above self-diagnosis method, the method further includes: during the entire process of the self-diagnosis method, the temperature measuring circuit periodically measures an ambient temperature, and transmits the ambient temperature to the main controller; The main controller compares the ambient temperature with temperature range data of the set of standard parameter values stored in the data storage circuit to determine whether over-temperature use exists; and if there is over-temperature use, the over-temperature is over-temperature Data is recorded in the data storage circuit.

Preferably, in the above self-diagnostic method, the self-diagnostic circuit board further includes an angle measuring circuit for measuring a mounting angle of the intelligent analog load cell, the self-diagnostic method further comprising: the self-diagnostic method The angle measuring circuit periodically measures the mounting angle and installs the mounting angle Transmitting to the main controller; and the main controller compares the installation angle with the installation angle range data in the set of standard parameter values stored in the data storage circuit to determine the intelligent analog scale Is the installation of the heavy sensor level?

Preferably, in the above self-diagnostic method, immediately after the step of converting the zero-point analog signal of the resistance stress piece into a zero-point digital signal to the main controller, the analog-to-digital conversion conversion circuit further includes The main controller determines whether to read the zero digital signal.

It will be appreciated that the above-described sensors of the present invention and their self-diagnostic methods can achieve self-diagnosis of faults, alarm and record the misuse of the sensor, improve the maintenance efficiency of the sensor, and ensure the service life of the sensor. Thus, the sensor of the present invention and its self-diagnostic method have significant advancements over prior art devices and diagnostic methods.

The foregoing description of the preferred embodiments of the invention, DRAWINGS

The accompanying drawings are included to provide a further understanding of the embodiments of the invention In the figure:

Figure 1 shows an implementation of the intelligent analog load cell of the present invention.

Figure 2 illustrates another implementation of the intelligent analog load cell of the present invention.

Figure 3 shows the electrical structure of the strain gage, the bridge circuit board, and the self-diagnostic circuit board in more detail.

Figure 4 shows a schematic diagram of a wireless networking diagnostic system employing the embodiment of Figure 1.

Figure 5 shows a schematic diagram of a wired networking diagnostic system employing the embodiment of Figure 1.

Figure 6 is a flow diagram of the main steps of a self-diagnostic method in accordance with the present invention. Description of the reference signs:

101 and 201 : elastomer;

102 and 202: group bridge circuit board;

103 and 203: strain gauges; 104 and 204 cable connectors;

105 and 205 cable lines;

106 and 206 self-diagnostic boards;

107 and 207 signal splitters;

108 and 208 sensor signal connectors;

109 and 209 communication connectors

Embodiments of the present invention will now be described in detail with reference to the drawings. Reference will now be made in detail to the preferred embodiments of the preferred embodiments Wherever possible, the same reference numerals reference Further, although the terms used in the present invention are selected from well-known public terms, some of the terms mentioned in the specification of the present invention may be selected by the applicant according to his or her judgment, and the detailed meaning thereof is herein. The description of the relevant part of the description. Furthermore, the invention is not limited by the actual terms used, but rather by the meaning of each term.

Figures 1 and 2 illustrate two implementations of the intelligent analog load cell of the present invention. For example, in the embodiment shown in FIG. 1, the intelligent analog load cell 100 of the present invention mainly comprises: an elastic body 101, a bridge circuit board 102, a strain gauge 103, a cable joint 104, a cable 105, and a self-diagnostic circuit. Board 106, signal shunt 107, sensor signal connector 108, and communication connector 109.

Specifically, in the smart analog load cell 100 shown in Fig. 1, the resistance stress piece 102, the bridge circuit board 103, and the cable joint 104 are both fixed to the elastic body 101. One end of the cable 105 is connected to the cable connector 104.

In particular, in accordance with the present invention, self-diagnostic circuit board 106 is coupled to bridge circuit board 103 via cable connector 104 and cable 105. The signal splitter 107 is connected to the other end of the cable 105. A sensor signal connector 108 and a communication connector 109 are connected to the signal splitter 107, respectively. The signal splitter 107 splits the signal from the self-diagnostic circuit board 106 into a sensor signal that is transmitted to the sensor signal connector 108 and a diagnostic signal that is transmitted to the communication connector 109.

When the elastic body 101 changes, causing a change in the resistance value of the strain gauge 102, the bridge circuit board 103 The signal output also changes as the resistance of the strain gauge 102 changes, and the signal is then transmitted to the self-diagnostic circuit board 106 for self-diagnosis of the smart analog load cell 100.

Preferably, in the embodiment shown in Figure 1, the self-diagnostic circuit board 106 is formed integrally with the signal splitter 107. In contrast, in another embodiment shown in FIG. 2, the self-diagnostic circuit board 106 is disposed on the elastic body 101.

Turning now to Figure 3, the electrical construction of the strain gage, the bridge circuit board, and the self-diagnostic circuit board is shown in more detail. The self-diagnostic circuit board 106 may further include: a main controller 301, a preset resistor (not shown), and an analog-to-digital conversion circuit 302 connected to the main controller 301, a voltage measuring circuit 303, a temperature measuring circuit 304, and a data storage. Circuit 305 and communication circuit 306. The analog-to-digital conversion circuit 302 is connected between the output of the bridge circuit board 103 and the main controller 301. The analog-to-digital conversion circuit 302 receives the output from the bridge circuit board 103, and converts the analog signal into a digital signal for transmission to the main control. 301. The voltage measuring circuit 303 measures the excitation signal of the resistance stress piece 102, and transmits the voltage data to the main controller 301. The temperature measuring circuit 304 measures the ambient temperature and transmits it to the main controller 301. A set of standard parameter values for the smart analog load cell 100 are stored in the data storage circuit 305. The communication circuit 306 is used for command interaction with an external device to transmit diagnostic information. The communication circuit 306 on the self-diagnostic circuit board 106 can be a wired communication circuit or a wireless communication circuit. The wired communication circuit can be a circuit based on a wired communication protocol such as RS232/422/485, CAN, USB, Ethernet, etc. The wireless communication circuit can be a wireless communication protocol based on WiFi, Zigbee, RFID, WirelessUSB, GPRS, etc. The resistance of the preset resistor is preferably set to correspond to the full-scale state of the intelligent analog load cell 100 of the present invention, that is, when the main controller causes the analog signal of the resistance stress sheet to flow through the preset resistor, it can be measured. The full-scale digital signal in its full-scale state.

According to a preferred embodiment of the present invention, in the above-described intelligent analog load cell 100, the self-diagnostic circuit board 106 may further include an angle measuring circuit (not shown) for measuring the mounting angle of the intelligent analog load cell. .

It can be understood that the electrical structures of the strain gauge, the bridge circuit board and the self-diagnostic circuit board shown in FIG. 3 are equally applicable to the embodiment of FIG. 2, and therefore the application of this embodiment will not be described again.

FIG. 4 is a schematic diagram of a wireless network diagnostic system using the embodiment shown in FIG. 1. A signal line of a plurality of intelligent analog load cells is connected to a signal input end of the meter, and the meter and sensor diagnostic information are completed by wireless transmission. Interaction. FIG. 5 is a schematic diagram of a wired network diagnostic system using the embodiment shown in FIG. 1. The signal lines of multiple intelligent analog load cells are connected to the signal input end of the meter, and the interaction between the instrument and the sensor diagnostic information is completed by wire. .

Moreover, those skilled in the art will appreciate that the smart analog load cell of Figure 2 can be applied to the wireless/wired networking diagnostic system of Figures 4 and 5 in a similar manner. Such an embodiment will not be described again here.

Figure 6 is a flow diagram of the main steps of a self-diagnostic method in accordance with the present invention. This self-diagnostic method 600 should be applied to the various embodiments of the intelligent analog load cell of the present invention described above.

The self-diagnosis method 600 of the present invention mainly comprises the following steps. First, the weight on the smart analog load cell is removed (step 601). In this step 601, the external device can send a command through the communication circuit to cause the intelligent analog load cell to enter the self-diagnosis mode. The analog to digital conversion circuit converts the zero point analog signal of the resistance stress piece into a zero point digital signal and transmits it to the main controller (step 602). The primary controller compares the zero digit digital signal to a zero point production value of the set of standard parameter values stored in the data storage circuit to determine if there is a zero point outage (step 603). The main controller causes the analog signal of the resistive stress sheet to flow through the preset resistor to measure the full-scale digital signal in the full-scale state (step 604). The master controller compares the full-scale digital signal to the full-scale output value of a set of standard parameter values stored in the data storage circuit to determine if there is a full-scale outage (step 605). The main controller outputs the result of the above judgment through the communication circuit (step 606).

In addition, according to a preferred embodiment of the present invention, in the self-diagnosis method 600 described above, the method further includes: during the entire process of the self-diagnosis method, the temperature measuring circuit periodically measures the ambient temperature, and transmits the ambient temperature to the main a controller that compares the ambient temperature with temperature range data of a set of standard parameter values stored in the data storage circuit to determine whether overtemperature is present; and if there is overtemperature use, over temperature Data is recorded in the data storage circuit.

In addition, according to another preferred embodiment of the present invention, the self-diagnostic circuit board may further include an angle measuring circuit for measuring a mounting angle of the smart analog load cell, the self-diagnostic method 600 may further include: Throughout the process, the angle measuring circuit periodically measures the mounting angle and transmits the mounting angle to the main controller; and the main controller compares the mounting angle with the set of standard parameter values stored in the data storage circuit The installation angle range data is compared to determine the intelligent analog weighing Whether the sensor is installed horizontally.

In another aspect, in the self-diagnosis method 600 of the present invention, immediately after the analog-to-digital conversion circuit converts the zero-point analog signal of the resistance stress piece into a zero-point digital signal and transmits the signal to the main controller, step 602 A step of the master controller determining whether to read the zero digital signal may be included.

The above sensor and self-diagnosis method of the invention can realize self-diagnosis of fault, alarm and record for faulty use of the sensor, improve maintenance efficiency of the sensor and ensure the service life of the sensor.

It will be apparent to those skilled in the art that various modifications and changes can be made in the above-described embodiments of the present invention without departing from the spirit and scope of the invention. Therefore, it is intended that the present invention cover the modifications and modifications of the invention

Claims

claims

1. An intelligent analog load sensor, including an elastomer, a resistance stress sheet fixed on the elastomer, a bridge circuit board and a cable joint, and a cable wire with one end connected to the cable joint, characterized by: , the intelligent analog load sensor further includes:

The self-diagnostic circuit board is connected to the bridge circuit board via the cable connector and the cable line; the signal splitter is connected to the other end of the cable line; and

The sensor signal connector and communication connector are respectively connected to the signal shunt,

Wherein, the signal splitter splits the signal from the self-diagnostic circuit board into a sensor signal transmitted to the sensor signal connector and a diagnostic signal transmitted to the communication connector.

2. The intelligent analog load sensor according to claim 1, characterized in that the self-diagnosis circuit board and the signal shunt are formed as a whole.

3. The intelligent analog load sensor according to claim 1, characterized in that the self-diagnosis circuit board is provided on the elastomer.

4. The intelligent analog load sensor according to claim 1, wherein the self-diagnosis circuit board includes: a main controller, a preset resistor, and an analog-to-digital conversion circuit connected to the main controller signal, Voltage measurement circuit, temperature measurement circuit, data storage circuit and communication circuit,

Wherein, the analog-to-digital conversion circuit is connected between the output end of the bridge circuit board and the main controller;

Wherein, the voltage measuring circuit measures the excitation signal of the resistive stress sheet

Wherein, the temperature measurement circuit measures the ambient temperature;

Wherein, a set of standard parameter values of the intelligent analog load sensor is stored in the data storage circuit.

5. The intelligent analog load sensor according to claim 4, wherein the self-diagnosis circuit board further includes an angle measurement circuit for measuring the installation angle of the intelligent analog load sensor.

6. A self-diagnosis method using the intelligent analog load sensor as claimed in claim 4 or 5, characterized in that it includes:

Remove the weight on the smart analog load cell;

The analog-to-digital conversion circuit converts the zero-point analog signal of the resistance stress sheet into a zero-point digital signal and transmits it to the main controller;

The main controller compares the zero-point digital signal with a zero-point production value in the set of standard parameter values stored in the data storage circuit to determine whether there is a zero-point out-of-tolerance;

The main controller causes the analog signal of the resistance stress sheet to flow through the preset resistor to measure the full-scale digital signal in the full-scale state;

The main controller compares the full-scale digital signal with the full-scale production value in the set of standard parameter values stored in the data storage circuit to determine whether there is a full-scale out-of-tolerance; and

The main controller outputs the above judgment result through the communication circuit.

7. The self-diagnosis method according to claim 6, further comprising:

During the entire process of the self-diagnosis method, the temperature measurement circuit regularly measures the ambient temperature and transmits the ambient temperature to the main controller;

The main controller compares the ambient temperature with the temperature range data in the set of standard parameter values stored in the data storage circuit to determine whether there is over-temperature use; and

If there is over-temperature use, the over-temperature data is recorded in the data storage circuit.

8. The self-diagnosis method of claim 6, wherein the self-diagnosis circuit board further includes an angle measurement circuit for measuring the installation angle of the intelligent analog load sensor, and the self-diagnosis method further includes:

During the entire process of the self-diagnosis method, the angle measurement circuit regularly measures the installation angle and transmits the installation angle to the main controller; and

The main controller compares the installation angle with the installation angle range data in the set of standard parameter values stored in the data storage circuit to determine whether the intelligent analog load sensor is installed properly. flat.

9. The self-diagnosis method according to claim 6, characterized in that, following the step of converting the zero-point analog signal of the resistive stress sheet into a zero-point digital signal by the analog-to-digital conversion circuit and transmitting it to the main controller After that, the step of determining whether the zero point digital signal is read by the main controller is also included.