A gravity detection sensor

Abstract

A gravity detection sensor is provided with a shielding cover, a metal deformation body and a circuit board are provided inside the shielding cover, a Wheatstone strain gauge is attached to the metal deformation body through epoxy AB glue, and the Wheatstone strain gauge includes a Wheatstone bridge formed by four resistors; the first corner point of the Wheatstone bridge is electrically connected to the sensor power pin, the second corner point of the Wheatstone bridge is electrically connected to the signal positive pin, the third corner point of the Wheatstone bridge is electrically connected to the sensor ground pin, and the fourth corner point of the Wheatstone bridge is electrically connected to the signal negative pin; the circuit board is also provided with a channel selector, a preamplifier, an analog-to-digital converter and a digital filter, the signal positive pin and the signal negative pin are electrically connected to the channel selector, the channel selector is electrically connected to the preamplifier, the preamplifier is electrically connected to the analog-to-digital converter, and the analog-to-digital converter is electrically connected to the digital filter. The present invention realizes active, independent and intermittent subsystem high-integration gravity measurement, has good energy-saving effect, is convenient for mass production, and has high precision.

Description

Technical Field

[0001] The invention belongs to the technical field of sensors, and in particular relates to a gravity detection sensor. Background Art

[0002] The gravity detection sensor is implemented using the piezoelectric effect. A weight and a piezoelectric sheet are integrated inside the sensor. The horizontal direction is calculated by the voltage generated in two orthogonal directions. The piezoelectric effect is that for heteropolar crystals without a symmetry center, the external force applied to the crystal will not only deform the crystal, but also change the polarization state of the crystal and establish an electric field inside the crystal. This phenomenon of polarization of the medium due to mechanical force is called the positive piezoelectric effect. It is mainly used in the intelligent switching of horizontal and vertical screens on mobile phones; the direction of taking photos; and gravity sensing games, such as balancing balls and racing games.

[0003] At present, the sensors used to detect mechanics on the market are generally implemented with piezoelectric films. The materials include constantan and polyurethane. They output mv / v signals. Users need to adjust the op amp zero and linearity later. They are large in size. Non-professional users have great differences in the adjustment methods and understanding of sensors. They have poor flexibility, high power consumption, and unguaranteed performance. They are not conducive to mass production and cannot meet users' needs for high precision. Summary of the invention

[0004] To this end, the present invention provides a gravity detection sensor that is flexible in use, energy-saving, and reduces power consumption without sacrificing performance, is convenient for mass production, and meets the high-precision needs of users.

[0005] In order to achieve the above object, the present invention provides the following technical solutions: a gravity detection sensor, comprising a shielding cover, wherein a metal deformation body and a circuit board are arranged inside the shielding cover, a Wheatstone strain gauge is attached to the metal deformation body through epoxy AB glue, and the Wheatstone strain gauge comprises a Wheatstone bridge formed by four resistors;

[0006] The circuit board is provided with a sensor power pin, a signal positive pin, a sensor ground pin and a signal negative pin; the first corner point of the Wheatstone bridge is electrically connected to the sensor power pin, the second corner point of the Wheatstone bridge is electrically connected to the signal positive pin, the third corner point of the Wheatstone bridge is electrically connected to the sensor ground pin, and the fourth corner point of the Wheatstone bridge is electrically connected to the signal negative pin;

[0007] The circuit board is also provided with a channel selector, a preamplifier, an analog-to-digital converter and a digital filter. The signal positive pin and the signal negative pin are electrically connected to the channel selector, the channel selector is electrically connected to the preamplifier, the preamplifier is electrically connected to the analog-to-digital converter, and the analog-to-digital converter is electrically connected to the digital filter.

[0008] As a preferred solution of the gravity detection sensor, the circuit board is further integrated with a temperature sensor, the temperature sensor is electrically connected to the channel selector, and the temperature sensor is used to perform temperature compensation on the gravity detection sensor;

[0009] The circuit board has a temperature measurement selection pin, and the temperature measurement selection pin is electrically connected to a temperature measurement diode.

[0010] As a preferred solution of the gravity detection sensor, the circuit board also integrates a communication module, a digital calibrator and a buffer, the digital filter is electrically connected to the digital calibrator, the digital calibrator is electrically connected to the buffer, and the buffer is electrically connected to the communication module.

[0011] As a preferred solution of the gravity detection sensor, the communication module controls the pressure signal through the I2C or SPI communication protocol to perform intelligent monitoring, and the communication module controls peripheral equipment through the monitored pressure signal.

[0012] As a preferred solution of the gravity detection sensor, the communication module has a clock pin, a data pin, an address selection pin and a communication selection pin integrated on a circuit board.

[0013] As a preferred solution of the gravity detection sensor, the circuit board is further integrated with a voltage regulator, and the voltage regulator has a power pin and a ground pin integrated on the circuit board.

[0014] As a preferred solution for the gravity detection sensor, the circuit board is also integrated with a hard interrupt comparison valve, which is used to monitor and compare the pressure output variable of the Wheatstone strain gauge to actively provide a pull-up voltage to the main control system to wake up the main system.

[0015] As a preferred solution of the gravity detection sensor, the circuit board is also integrated with an oscillator, and the oscillator is used to repeatedly generate gravity electronic signals;

[0016] The circuit board is also integrated with a one-time editable memory, and the one-time editable memory is burned with the trigger range and trigger time of the gravity detection sensor.

[0017] As a preferred solution of the gravity detection sensor, the circuit board is also integrated with a charge pump, and the charge pump is used to generate a higher pulse voltage output through a lower input voltage.

[0018] As a preferred solution of the gravity detection sensor, the material of the metal deformation body is copper, aluminum, steel or alloy steel.

[0019] The present invention has the following advantages: a shielding cover is provided, a metal deformation body and a circuit board are provided inside the shielding cover, a Wheatstone strain gauge is attached to the metal deformation body through epoxy AB glue, and the Wheatstone strain gauge includes a Wheatstone bridge formed by four resistors; the circuit board is provided with a sensor power pin, a signal positive pin, a sensor ground pin and a signal negative pin; the first corner point of the Wheatstone bridge is electrically connected to the sensor power pin, the second corner point of the Wheatstone bridge is electrically connected to the signal positive pin, the third corner point of the Wheatstone bridge is electrically connected to the sensor ground pin, and the fourth corner point of the Wheatstone bridge is electrically connected to the signal negative pin; the circuit board is also provided with a channel selector, a preamplifier, an analog-to-digital converter and a digital filter, the signal positive pin and the signal negative pin are electrically connected to the channel selector, the channel selector is electrically connected to the preamplifier, the preamplifier is electrically connected to the analog-to-digital converter, and the analog-to-digital converter is electrically connected to the digital filter. The present invention can realize active, independent, and highly integrated gravity measurement of intermittent subsystems, reduce the working cycle frequency and period of the system set, thereby improving the flexibility of use of the entire system, with good energy-saving effect, low power consumption, and no sacrifice of performance, which greatly facilitates the mass production of sensors and meets the user's demand for high usage accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0021] The structures, proportions, sizes, etc. illustrated in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with the technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantial technical significance. Any structural modification, change in proportion or adjustment of size shall still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0022] Figure 1 It is a schematic diagram of the decomposition of the gravity detection sensor provided in the embodiment of the present invention;

[0023] Figure 2 The diagram is a schematic diagram of the circuit principle of the gravity detection sensor provided in an embodiment of the present invention.

[0024] In the figure, 1. shielding cover; 2. metal deformation body; 3. circuit board; 4. Wheatstone strain gauge; 5. sensor power pin; 6. signal positive pin; 7. sensor ground pin; 8. signal negative pin; 9. channel selector; 10. preamplifier; 11. analog-to-digital converter; 12. digital filter; 13. temperature sensor; 14. diode for temperature measurement; 15. communication module; 16. digital calibrator; 17. buffer; 18. clock pin; 19. data pin; 20. address selection pin; 21. charge pump; 22. communication selection pin; 23. hard interrupt comparison valve; 24. oscillator; 25. one-time editable memory. DETAILED DESCRIPTION

[0025] The following is a description of the implementation of the present invention by specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] See also Figure 1 and Figure 2 , a gravity detection sensor is provided, comprising a shielding cover 1, wherein a metal deformation body 2 and a circuit board 3 are arranged inside the shielding cover 1, a Wheatstone strain gauge 4 is attached to the metal deformation body 2 through epoxy AB glue, and the Wheatstone strain gauge 4 comprises a Wheatstone bridge formed by four resistors;

[0027] The circuit board 3 is provided with a sensor power pin 5, a signal positive pin 6, a sensor ground pin 7 and a signal negative pin 8; the first corner point of the Wheatstone bridge is electrically connected to the sensor power pin 5, the second corner point of the Wheatstone bridge is electrically connected to the signal positive pin 6, the third corner point of the Wheatstone bridge is electrically connected to the sensor ground pin 7, and the fourth corner point of the Wheatstone bridge is electrically connected to the signal negative pin 8;

[0028] The circuit board 3 is also provided with a channel selector 9, a preamplifier 10, an analog-to-digital converter 11 and a digital filter 12. The signal positive pin 6 and the signal negative pin 8 are electrically connected to the channel selector 9, the channel selector 9 is electrically connected to the preamplifier 10, the preamplifier 10 is electrically connected to the analog-to-digital converter 11, and the analog-to-digital converter 11 is electrically connected to the digital filter 12.

[0029] In this embodiment, the circuit board 3 is also integrated with a temperature sensor 13, which is electrically connected to the channel selector 9, and the temperature sensor 13 is used to perform temperature compensation on the gravity detection sensor; the circuit board 3 has a temperature measurement selection pin, and the temperature measurement selection pin is electrically connected to a temperature measurement diode 14. The circuit board 3 is also integrated with a communication module 15, a digital calibrator 16 and a buffer 17, the digital filter 12 is electrically connected to the digital calibrator 16, the digital calibrator 16 is electrically connected to the buffer 17, and the buffer 17 is electrically connected to the communication module 15. The communication module 15 controls the pressure signal through the I2C or SPI communication protocol for intelligent monitoring, and the communication module 15 controls peripheral equipment through the monitored pressure signal.

[0030] In this embodiment, the communication module 15 has a clock pin 18, a data pin 19, an address selection pin 20 and a communication selection pin 22 integrated on the circuit board 3. The circuit board 3 also integrates a voltage regulator 26, and the voltage regulator 26 has a power pin and a ground pin integrated on the circuit board 3. The circuit board 3 also integrates a hard interrupt comparison valve 23, and the hard interrupt comparison valve 23 is used to monitor and compare the pressure output variable of the Wheatstone strain gauge 4 to actively provide a pull-up voltage to the main control system to wake up the main system.

[0031] In this embodiment, the circuit board 3 is further integrated with an oscillator 24, which is used to repeatedly generate gravity electronic signals; the circuit board 3 is further integrated with a one-time editable memory 25, which is burned with the trigger range and trigger time of the gravity detection sensor. The circuit board 3 is further integrated with a charge pump 21, which is used to generate a higher pulse voltage output through a lower input voltage.

[0032] Specifically, the present invention uses a piezoelectric film etched with four resistors of a Wheatstone bridge as the first zone circuit, a conditioning chip with functions such as pressure linearity, zero point, temperature compensation and hard interrupt control as the second zone circuit, and a voltage regulator 26 with an amplification function that simultaneously outputs analog signals and digital signals as the third zone circuit.

[0033] The present invention performs multi-stage amplification and signal processing on the Wheatstone bridge signal with metal strain film at the same time, but the output function can be used flexibly in the application. When the main system is asleep, the second zone circuit area performs intermittent power supply and output force signal, and compares the pressure output variable of the pressure core in the first zone through the internally configured threshold, so as to actively provide the main control system with a pull-up voltage to achieve the ability to wake up the main system. Secondly, after the main system is turned on, the second zone is controlled through the I2C or SPI communication protocol to cooperate with the output pressure signal of the first zone for intelligent monitoring, and the monitored pressure signal can be used to control other peripheral power equipment.

[0034] Specifically, the structure uses adhesive and semiconductor packaging technology, and in particular, in the structural design of the metal deformation body 2, in order to facilitate users to ensure that the accuracy of the force signal is not affected during installation, the metal deformation body 2 is designed as an internal countersunk hole. By designing a dual control system, the functions of the second zone and the third zone can be controlled simultaneously, achieving a safer effect.

[0035] The present invention designs energy-saving control in the circuit, and designs an intermittent stable power input and intermittent output mode in the second zone circuit chip, which can quickly and fully read the pressure signal while minimizing power consumption. The second zone circuit of the present invention can be configured with flexible active acquisition signals when the system is powered on, and the time can be selected according to application needs.

[0036] In one embodiment of the gravity detection sensor, the circuit board 3 is designed to prevent electromagnetic interference, and the magnetic field noise signal in the metal cover is processed to prevent unclean signals from entering the system and affecting the system accuracy, thereby improving the application in harsh environments. In addition, the bottom of the circuit board 3 is perforated, and the outer wall retains the wire design, with a wire diameter in the range of 0.1-2mm, which greatly meets the user's installation needs from the bottom and side.

[0037] Assistance Figure 2 , the production process of gravity detection sensor is as follows:

[0038] First, the Wheatstone strain gauge 4 is applied to the metal deformable body 2 (copper, aluminum, steel or alloy steel) by dripping AB epoxy glue, the deformation thickness of the metal deformable body 2 is calculated by the existing mechanical simulation software, and then the metal deformable body is fixed in one piece by multiple high-temperature curing;

[0039] Second, use the standard chromium iron welding method to connect the input and output pads on the strain film with metal wires, and connect them to the bottom PCBA according to the schematic diagram;

[0040] Third, use a spraying device to regularly apply glue required for fixing the metal shielding cover 1 around the bottom of the metal deformation body 2;

[0041] Fourth, fix the circuit board 3 with the components mounted on it on the metal deformation body 2 coated with adhesive in the first step;

[0042] Fifth, bake the fourth semi-finished product at high temperature to fix the position;

[0043] Sixth, complete product packaging and conduct performance testing.

[0044] The present invention is provided with a shielding cover 1, wherein a metal deformation body 2 and a circuit board 3 are provided inside the shielding cover 1, a Wheatstone strain gauge 4 is attached to the metal deformation body 2 through epoxy AB glue, and the Wheatstone strain gauge 4 includes a Wheatstone bridge formed by four resistors; the circuit board 3 is provided with a sensor power pin 5, a signal positive pin 6, a sensor ground pin 7 and a signal negative pin 8; the first corner point of the Wheatstone bridge is electrically connected to the sensor power pin 5, the second corner point of the Wheatstone bridge is electrically connected to the signal positive pin 6, the third corner point of the Wheatstone bridge is electrically connected to the sensor ground pin 7, and the fourth corner point of the Wheatstone bridge is electrically connected to the signal negative pin 8; the circuit board 3 is also provided with a channel selector 9, a preamplifier 10, an analog-to-digital converter 11 and a digital filter 12, the signal positive pin 6 and the signal negative pin 8 are electrically connected to the channel selector 9, the channel selector 9 is electrically connected to the preamplifier 10, the preamplifier 10 is electrically connected to the analog-to-digital converter 11, and the analog-to-digital converter 11 is electrically connected to the digital filter 12. The present invention can realize active, independent, and highly integrated gravity measurement of intermittent subsystems, reduce the working cycle frequency and period of the system set, thereby improving the flexibility of use of the entire system, with good energy-saving effect, low power consumption, and no sacrifice of performance, which greatly facilitates the mass production of sensors and meets the user's demand for high usage accuracy.

[0045] Although the present invention has been described in detail above by general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A gravity detection sensor, characterized in that: The invention comprises a shielding cover (1), wherein a metal deformation body (2) and a circuit board (3) are arranged inside the shielding cover (1), a Wheatstone strain gauge (4) is attached to the metal deformation body (2) by epoxy AB glue, and the Wheatstone strain gauge (4) comprises a Wheatstone bridge formed by four resistors; The circuit board (3) is provided with a sensor power pin (5), a signal positive pin (6), a sensor ground pin (7) and a signal negative pin (8); a first corner point of the Wheatstone bridge is electrically connected to the sensor power pin (5), a second corner point of the Wheatstone bridge is electrically connected to the signal positive pin (6), a third corner point of the Wheatstone bridge is electrically connected to the sensor ground pin (7), and a fourth corner point of the Wheatstone bridge is electrically connected to the signal negative pin (8); The circuit board (3) is also provided with a channel selector (9), a preamplifier (10), an analog-to-digital converter (11) and a digital filter (12); the signal positive pin (6) and the signal negative pin (8) are electrically connected to the channel selector (9); the channel selector (9) is electrically connected to the preamplifier (10); the preamplifier (10) is electrically connected to the analog-to-digital converter (11); and the analog-to-digital converter (11) is electrically connected to the digital filter (12); The circuit board (3) is also integrated with a hard interrupt comparison valve (23), and the hard interrupt comparison valve (23) is used to monitor and compare the pressure output variable of the Wheatstone strain gauge (4) to actively provide a pull-up voltage to the main control system to wake up the main system; The circuit board (3) is also integrated with an oscillator (24), and the oscillator (24) is used to repeatedly generate gravity electron signals; The circuit board (3) is also integrated with a one-time editable memory (25), and the one-time editable memory (25) is burned with the trigger range and trigger time of the gravity detection sensor; The circuit board (3) is further integrated with a charge pump (21), and the charge pump (21) is used to generate a higher pulse voltage output through a lower input voltage; A piezoelectric film etched with four resistors of a Wheatstone bridge is used as the first zone circuit, a conditioning chip with functions such as pressure linearity, zero point, temperature compensation and hard interrupt control is used as the second zone circuit, and a voltage regulator (26) with an amplification function that simultaneously outputs analog signals and digital signals is used as the third zone circuit; When the main system is asleep, the second zone circuit area performs intermittent power supply and output force signals, and compares the pressure output variables of the pressure core in the first zone through internally configured thresholds, so as to actively provide the main control system with a pull-up voltage to achieve the ability to wake up the main system. After the main system is turned on, the second zone is controlled through the I2C or SPI communication protocol to cooperate with the output pressure signal of the first zone for intelligent monitoring. The monitored pressure signal can be used to control other peripheral power equipment; The production process of the gravity detection sensor is as follows: First, the Wheatstone strain gauge (4) is applied to the metal deformable body (2) by dripping AB epoxy glue, the deformation thickness of the metal deformable body (2) is calculated by mechanical simulation software, and then the metal deformable body is fixed in an integrated manner through multiple high-temperature curing; Second, use the standard chromium iron welding method to connect the input and output pads on the strain film with metal wires, and connect them to the bottom PCBA according to the schematic diagram; Third, using a spraying device, regularly apply glue required for fixing the metal shielding cover (1) around the bottom of the metal deformation body (2); Fourth, fix the circuit board (3) with the components mounted on it onto the metal deformation body (2) coated with the adhesive in the first step; Fifth, bake the fourth semi-finished product at high temperature to fix the position; Sixth, complete product packaging and conduct performance testing.

2. A gravity detection sensor according to claim 1, characterized in that: The circuit board (3) is also integrated with a temperature sensor (13), the temperature sensor (13) is electrically connected to the channel selector (9), and the temperature sensor (13) is used to perform temperature compensation on the gravity detection sensor; The circuit board (3) has a temperature measurement selection pin, and the temperature measurement selection pin is electrically connected to a temperature measurement diode (14).

3. A gravity detection sensor according to claim 1, characterized in that: The circuit board (3) is also integrated with a communication module (15), a digital calibrator (16) and a buffer (17); the digital filter (12) is electrically connected to the digital calibrator (16); the digital calibrator (16) is electrically connected to the buffer (17); and the buffer (17) is electrically connected to the communication module (15).

4. A gravity detection sensor according to claim 3, characterized in that: The communication module (15) controls the pressure signal through the I2C or SPI communication protocol to perform intelligent monitoring, and the communication module (15) controls peripheral equipment through the monitored pressure signal.

5. A gravity detection sensor according to claim 3, characterized in that: The communication module (15) has a clock pin (18), a data pin (19), an address selection pin (20) and a communication selection pin (22) which are integrated on a circuit board (3).

6. The gravity detection sensor according to claim 1, characterized in that: The circuit board (3) is also integrated with a voltage regulator (26), and the voltage regulator (26) has a power pin and a ground pin integrated on the circuit board (3).

7. The gravity detection sensor according to claim 1, characterized in that: The material of the metal deformation body (2) is copper, aluminum, steel or alloy steel.

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