Adaptive linear control gravity meter constant temperature system and working method

Abstract

The application relates to a self-adaptive linear control gravity meter constant temperature system and a working method, which comprises a precision circuit subsystem, a first subsystem, a second subsystem, a damping support and a gravity sensor, takes the constant temperature and uniform temperature effects of core inertial devices as cores, and considers the temperature drift and heat dissipation characteristics of electronic devices. The application adopts a current control type linear constant temperature control circuit with current adjustable function, suppresses electromagnetic interference and improves temperature control reliability. The application adopts graphite material with good heat equalizing effect to enhance the heat equalizing property of the gravity sensor, fills the gravity sensor with appropriate heat equalizing inert gas, adopts multi-point self-adjusting constant temperature control at the inert core parts such as the gravity sensor, realizes the global temperature field balance and stability of the inert core area such as the gravity sensor, has strong stability against dynamic disturbance, and is beneficial to improving the gravity measurement resolution and precision.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of inertial measurement, and particularly relates to a self-adaptive linear control gravity meter constant temperature system and a working method. BACKGROUND

[0002] In the field of high-precision dynamic gravity measurement, high-precision constant temperature control needs to be implemented for inertial core parts such as gravity sensors. In the field of portable flow relative gravity meters, domestic gravity meter equipment is gradually developing, but breakthroughs cannot be achieved in the field of constant temperature systems with small volume and low power consumption. In the prior art, the structure cannot effectively balance the heat dissipation and stability, the temperature field of the hollow gravity sensor is unbalanced, the constant temperature system has large power consumption, general stability and is difficult to adapt to extreme high and low temperature environments, and the like. In the circuit control, a single analog or digital PWM control mode is generally used, the former has poor adaptability and is inconvenient to debug, and the latter has good man-machine nature but large electromagnetic interference, which is not conducive to high-precision gravity measurement. SUMMARY

[0003] The application aims to overcome the shortcomings of the prior art, and provides a self-adaptive linear control gravity meter constant temperature system and a working method, which takes the constant temperature and uniform temperature effects of core inertial devices as the core, considers the temperature drift and heat dissipation characteristics of electronic devices, and adopts a current control type linear constant temperature control circuit with current adjustable function. The constant temperature and uniform temperature effects of the gravity sensor and other inertial core parts are greatly improved, electromagnetic interference is inhibited, and temperature control reliability is improved, which is conducive to further improving the measurement resolution and precision of the inertial gravity sensor.

[0004] The application solves the technical problems by adopting the following technical solutions:

[0005] A self-adaptive linear control gravity meter constant temperature system and a working method, comprising a precision circuit subsystem, a primary subsystem, a secondary subsystem, a damping strut and a gravity sensor, wherein the top and bottom of the secondary subsystem are respectively provided with damping struts for damping the vibration of the gravity meter constant temperature system, the primary subsystem and the precision circuit subsystem are arranged in the secondary subsystem, and the gravity sensor is arranged in the primary subsystem.

[0006] Moreover, the first subsystem comprises a first upper end heating film belt, a first sidewall heating film belt, a first lower end heating film belt, a first subsystem temperature measuring thermistor and a first heat preservation aerogel, the outer four sides of the gravity sensor are first paved with graphite heat conduction material, the first upper end heating film belt, the first sidewall heating film belt and the first lower end heating film belt are respectively pasted on the upper end, the sidewall and the lower end of the gravity sensor paved with the graphite heat conduction material, the gravity sensor pasted with the heating film belt is tightly wrapped by the first heat preservation aerogel and arranged inside the second subsystem, and the first subsystem temperature measuring thermistor is arranged at the upper, middle and lower ends of the gravity sensor.

[0007] Moreover, the precision circuit subsystem comprises a precision circuit module, a heating circuit module, a heating circuit heating film belt, a heating circuit heat preservation aerogel, a precision circuit heating film belt and a precision circuit heat preservation aerogel, the precision circuit module is arranged above the first subsystem after pasting the precision circuit heating film belt and wrapping the precision circuit heat preservation aerogel, and the heating circuit module is arranged above the precision circuit module after pasting the heating circuit heating film belt and wrapping the heating circuit heat preservation aerogel.

[0008] Moreover, the second subsystem comprises a shell, a second subsystem temperature measuring thermistor, a second heating film belt and a second heat preservation aerogel, the shell is in a cylindrical shape, is processed into a cylindrical barrel by light purple copper and reserves a groove for placing the second subsystem temperature measuring thermistor, the shell outer wall is pasted with the second heating belt, and the second heating belt is tightly wrapped by the second heat preservation aerogel.

[0009] Moreover, the precision circuit module comprises a precision circuit of a gravity sensor constant temperature multi-point control self-adjusting circuit and a precision circuit of a second and precision circuit board constant temperature temperature measuring circuit, the precision circuit of the gravity sensor constant temperature multi-point control self-adjusting circuit comprises a first operational amplifier circuit, a second operational amplifier circuit, a third operational amplifier circuit, a first single-channel precision instrument operational amplifier, a first 24-bit A / D converter, a double-channel precision instrument operational amplifier and an ARM, the output end of the second operational amplifier circuit is connected with the input end of the first single-channel precision instrument operational amplifier, the output end of the first single-channel precision instrument operational amplifier is connected with the input end of the first 24-bit A / D converter, the output end of the first 24-bit A / D converter, the output ends of the first, second and third operational amplifier circuits are respectively connected with the input end of the double-channel precision instrument operational amplifier, and the output end of the double-channel precision instrument operational amplifier is connected with the ARM.

[0010] Moreover, the precision circuit of the secondary and precision circuit board constant temperature temperature measurement circuit comprises a fourth operational amplifier circuit, a fifth operational amplifier circuit, a second single-channel precision instrument operational amplifier, a third single-channel precision instrument operational amplifier, a second 24-bit A / D converter, a third 24-bit A / D converter and an ARM, wherein the fourth operational amplifier circuit is connected to the ARM in sequence through the second single-channel precision instrument operational amplifier and the second 24-bit A / D converter, and the fifth operational amplifier circuit is connected to the ARM in sequence through the third single-channel precision instrument operational amplifier and the third 24-bit A / D converter.

[0011] Moreover, the current control type digital real-time adjustable linear temperature control circuit with current adjustable function (the circuit is integrated in the precision circuit module and the heating circuit module, and is not repeated again) comprises a PWM control signal output in real time by an ARM processor according to a control algorithm, an optical coupler isolator, a PAC module, linear conversion of 0% to 100% PWM digital signals into 4 to 20 mA current output, and a current adjustable circuit driven by a Darlington tube and a current detection type operational amplifier to drive the heating sheet to work.

[0012] A working method of a self-adaptive adjustment linear control gravimeter constant temperature system, comprising the following steps:

[0013] Step 1, a two-stage six-way constant temperature system is constructed, the core of which is to enhance the constant temperature and uniform temperature effect of the core inertial device, and the temperature drift and heat dissipation characteristics of electronic devices are taken into account, the circuit board constant temperature system is designed as a precision circuit module and a heating circuit module, and the heating circuit module adopts a switching temperature control mode.

[0014] Step 2, a precision voltage reference chip is used to generate a high-precision reference voltage, a precision instrument operational amplifier and a high-precision metal film resistor are used to construct a grounded constant current source circuit, a constant current suitable for driving the work of the thermistor is generated, which is beneficial to improve the temperature measurement precision and provides a precision temperature measurement basis for high-precision constant temperature control.

[0015] Step 3, the heating films on the side wall, the upper end and the lower end of the cylindrical gravity sensor in the primary constant temperature subsystem are controlled separately, and the real-time temperature values are fed back by the primary subsystem temperature measurement thermistors, so that three-point constant temperature control is realized; the thermistor at the center is used as the temperature control reference, a temperature-voltage comparison method is adopted, and the ARM control strategy is used to correct the upper and lower end temperature control values to be consistent with the center end temperature value in real time, so that the axial temperature gradient difference is greatly reduced, and a temperature field close to equilibrium is created.

[0016] The advantages and positive effects of the present application are:

[0017] 1. The application constructs a self-adaptive adjustment linear control gravity meter constant temperature system through a precision circuit subsystem, a first subsystem, a second subsystem, a damping strut and a gravity sensor, takes the enhancement of the constant temperature and the uniform temperature effect of the core inertial device as the core, and considers the temperature drift and the heat dissipation characteristics of the electronic device. The application adopts a current control type linear constant temperature control circuit with current adjustable function, suppresses electromagnetic interference and improves temperature control reliability. The application adopts graphite material with good heat equalizing effect to enhance the heat equalizing property of the gravity sensor, fills the gravity sensor with appropriate heat equalizing inert gas, adopts multi-point self-adjusting constant temperature control at the inert core parts such as the gravity sensor, realizes the global temperature field balance and stability of the inert core area such as the gravity sensor, has strong anti-dynamic disturbance stability, and is beneficial to improving the gravity measurement resolution and precision.

[0018] 2. The application constructs a multi-channel multi-point constant temperature control system, fills the closed hollow gravity sensor with appropriate helium, and spreads appropriate graphite material on the red copper structure, so as to create a balanced or close-to-balanced temperature field for the gravity sensor. The temperature drift and the heat dissipation characteristics of the electronic device are considered, which is beneficial to the construction of a low-power consumption and high-stability constant temperature system.

[0019] 3. The application constructs a digital real-time adjustable linear temperature control circuit, proposes a current control type linear constant temperature control circuit with current adjustable function, effectively combines the digital processing circuit and the analog driving circuit, greatly improves the feasibility and low-power consumption of the circuit implementation, the flexibility of temperature control debugging, and greatly suppresses the electromagnetic interference caused by the traditional switch temperature control mode.

[0020] 4. The application constructs a load ground type constant current source driving thermistor temperature measurement circuit with constant current commutation driving function, and the circuit design is simple and smart. The load is made to be common ground, so that the output constant current is easier to realize and stabilize, the influence of the ground level on the load and the circuit is avoided, and the common mode influence is effectively suppressed by using the output resistance voltage of the instrument operational amplifier.

[0021] 5. The upper, middle and lower constant temperature control of the cylindrical gravity sensor adopts a self-correction strategy to realize the global temperature field to reach a balanced and stable state, designs a three-point temperature comparison circuit, and adopts a one-point driving multi-point self-adjusting control strategy to realize real-time dynamic self-adaptive correction, optimizes the control flexibility and improves the control efficiency. DETAILED DESCRIPTION

[0022] Figure 1 It is a structural schematic diagram of the multi-point multi-channel constant temperature control system of the application;

[0023] Figure 2 It is a gravity sensor constant temperature multi-point control self-adjusting circuit diagram of the application;

[0024] Figure 3This is a circuit diagram of the secondary and precision circuit board constant temperature measurement circuit of the present invention;

[0025] Figure 4 This is a circuit diagram of the digitally adjustable linear temperature control system of the present invention. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to the accompanying drawings.

[0027] An adaptively adjustable linear control gravimeter temperature control system and its operating method, such as... Figure 1 As shown, it includes a precision circuit subsystem, a primary subsystem, a secondary subsystem, vibration damping supports, and a gravity sensor (the gravity sensor is cylindrical). Vibration damping supports are provided at the top and bottom of the secondary subsystem to reduce the vibration of the gravimeter's constant temperature system. The primary subsystem and the precision circuit subsystem are located inside the secondary subsystem, and the gravity sensor is located inside the primary subsystem.

[0028] The primary subsystem includes a primary upper heating film strip, a primary sidewall heating film strip, a primary lower heating film strip, a primary subsystem temperature-sensing thermistor, and a primary thermal insulation aerogel. The gravity sensor is first covered with graphite thermal conductive material. The primary upper heating film strip, the primary sidewall heating film strip, and the primary lower heating film strip are respectively attached to the upper, sidewall, and lower ends of the gravity sensor covered with graphite thermal conductive material. The gravity sensor with the heating film strip attached is tightly wrapped and set inside the secondary subsystem by the primary thermal insulation aerogel. The primary subsystem temperature-sensing thermistors are respectively arranged at the upper, middle, and lower ends of the gravity sensor.

[0029] The dense circuit subsystem includes a precision circuit module, a heating circuit module, a heating film strip for the heating circuit, a heat-insulating aerogel for the heating circuit, and a precision circuit heating film strip and a precision circuit heat-insulating aerogel. After the precision circuit module is attached with the precision circuit heating film strip and wrapped with the precision circuit heat-insulating aerogel, it is placed above the primary subsystem. After the heating circuit module is attached with the heating film strip and wrapped with the heat-insulating aerogel, it is placed above the precision circuit module (the heating module dissipates heat through a thermal pad connected to the metal top cover).

[0030] The secondary subsystem includes an outer shell, a secondary subsystem temperature sensor, a secondary heating film, and a secondary thermal insulation aerogel. The outer shell is cylindrical, made of lightweight copper and machined into a cylindrical body (the top cover is removable). A groove is reserved to place the secondary subsystem temperature sensor. The inner diameter of the cylindrical body is exactly matched with the primary constant temperature subsystem. The secondary heating film is pasted on the outer wall of the outer shell (except for the top cover), and then the secondary aerogel is used for thermal insulation to tightly wrap it.

[0031] The precision circuit module's thermostatic subsystem is positioned above the primary thermostatic subsystem and between the heating circuit module's thermostatic subsystem. The primary thermostatic subsystem employs a three-point thermostatic control method, aiming to achieve a near-zero temperature gradient across the upper, middle, and lower temperature fields of the cylindrical gravity sensor. Both the secondary thermostatic subsystem and the precision circuit module utilize single-point control, respectively designed to resist the impact of external temperature changes and provide a stable temperature environment for the precision circuit module. The heating circuit module uses a switching control mode. When the detected external temperature is high (above a certain set temperature value), the heating circuit module pauses its control operation to ensure timely heat dissipation; when the detected external temperature is lower than a certain set temperature value, the heating circuit module activates its control operation to maintain heat supply.

[0032] like Figure 2 As shown, the precision circuit module includes a precision circuit for a gravity sensor constant temperature multi-point control self-adjustment circuit and a precision circuit for a secondary precision circuit board constant temperature measurement circuit. The precision circuit for the gravity sensor constant temperature multi-point control self-adjustment circuit includes: a first operational amplifier circuit, a second operational amplifier circuit, a third operational amplifier circuit, a first single-channel precision instrument operational amplifier, a first 24-bit A / D converter, a dual-channel precision instrument operational amplifier, and an ARM. The output of the second operational amplifier circuit is connected to the input of the first single-channel precision instrument operational amplifier. The output of the first single-channel precision instrument operational amplifier is connected to the input of the first 24-bit A / D converter. The outputs of the first 24-bit A / D converter, the first operational amplifier circuit, the second operational amplifier circuit, and the third operational amplifier circuit are respectively connected to the input of the dual-channel precision instrument operational amplifier. The output of the dual-channel precision instrument operational amplifier is connected to the ARM.

[0033] Precision voltage reference chip (temperature coefficient ≤20ppm / ℃) provides ( High-precision reference voltage. Utilizing load grounding technology, high-precision... Voltage and Precision Instrument Operational Amplifier LTC2053, Thermistor (Load resistor), precision standard resistor (Accuracy error) High-precision metal film resistors (Constant current resistor, accuracy error) Construct a constant current source circuit with the load grounded. Among them, , For the filter capacitor, the capacitance value is set to... ,resistance , respectively with , Construct a filter circuit, which serves as a buffer for both pull-down and pull-up connections. The calculation formula for this load-grounded constant current source is:

[0034]

[0035] wherein is a constant current, the size of which can be determined according to the ideal working current required by the thermistor, and is known, the size of which depends on the value. The voltages formed across the thermistor and the precision standard resistor by the current flowing through them are respectively:

[0036]

[0037] wherein is the thermistor . The reference voltage of the A / D converter LTC2380-24 is directly provided by the same precision voltage reference chip High-precision reference voltage, so the conversion digital quantity D of the A / D converter is related to:

[0038]

[0039] wherein n is the number of bits of the A / D converter (LTC2380-24 is a 24-bit analog-to-digital converter, so n=24). It can be known from the conversion digital quantity D of the A / D converter that the final digital quantity D is only related to the load thermistor and the precision standard resistor , which guarantees the high precision, long-term stability of the standard resistor and the high sensitivity of the thermistor , so high-precision temperature measurement can be realized.

[0040] As shown in Figure 3 , the precision circuit of the precision circuit board constant-temperature temperature measurement circuit includes a fourth operational amplifier circuit, a fifth operational amplifier circuit, a second single-channel precision instrument operational amplifier, a third single-channel precision instrument operational amplifier, a second 24-bit A / D converter, a third 24-bit A / D converter, and an ARM, wherein the fourth operational amplifier circuit is connected to the ARM through the second single-channel precision instrument operational amplifier and the second 24-bit A / D converter in sequence, and the fifth operational amplifier circuit is connected to the ARM through the third single-channel precision instrument operational amplifier and the third 24-bit A / D converter in sequence.

[0041] The heating film strips of the side wall, the upper end, and the lower end of the cylindrical gravity sensor in the primary constant-temperature subsystem are separately controlled to heat, and the temperature of the upper end, the middle end, and the lower end is detected by the thermistors , and (three thermistors are grounded in common). The thermistor The detected temperature-voltage value is collected and processed by a 24-bit A / D converter, while the upper and lower thermistors and The high-potential end voltage and the thermistors The high-potential end voltage is differentially amplified (precision instrument amplifier) and output. When the thermistors 、 and The high-potential end voltage difference is 0, the upper, middle and lower temperature fields of the cylindrical gravity sensor reach equal equilibrium state; when the thermistors 、 and The high-potential end voltage difference is not 0, the upper, middle and lower temperature fields of the cylindrical gravity sensor do not reach equal equilibrium state, and the control needs to be corrected in the ARM controller to achieve the equal equilibrium state of the temperature field. The center of the cylindrical gravity sensor is set as The constant temperature control value is , the upper end The constant temperature control value is , and the lower end The constant temperature control value is , and the overall temperature control value is , ( ) and The high-potential end voltage difference is converted into temperature quantity A, and The high-potential end voltage difference is converted into temperature quantity B, then the correction strategy relationship is:

[0042]

[0043] When A and B are not zero, the real-time correction of and is performed in the ARM controller so as to reach When A and B are zero, the temperature field of the cylindrical gravity sensor has reached equal equilibrium state. The correction of and is performed in real time to keep equal, which is synchronized with the constant temperature system control to ensure that the temperature field of the gravity sensor is stable at any time.

[0044] As shown in Figure 4 , the real-time output PWM control signal is input to the PAC module (digital signal to analog signal chip) through the optocoupler isolator, and the 0%~100% PWM digital signal is linearly converted into 4~20mA current output, and then the current adjustable circuit driven by the Darlington tube and the current detection type operational amplifier drives the heating sheet to work.

[0045] It should be emphasized that the embodiments of the present application are illustrative only and not restrictive, thus the present application includes and is not limited to the embodiments described in the specific embodiments, any other embodiments derived by those skilled in the art according to the technical solutions of the present application also belong to the scope of protection of the present application.

Claims

1. An adaptively regulated linear control gravimeter thermostat system, characterized by: The gravity meter comprises a precision circuit subsystem, a first subsystem, a second subsystem, a damping strut and a gravity sensor, wherein the top and bottom of the second subsystem are respectively provided with the damping strut, the damping strut is used for damping the vibration of the gravity meter constant temperature system, the first subsystem and the precision circuit subsystem are arranged inside the second subsystem, and the gravity sensor is arranged inside the first subsystem. The precision circuit subsystem comprises a precision circuit module, a heating circuit module, a heating circuit heating film belt, a heating circuit heat preservation aerogel, a precision circuit heating film belt and a precision circuit heat preservation aerogel, the precision circuit module is arranged above the first subsystem after the precision circuit module is pasted on the precision circuit heating film belt and wrapped with the precision circuit heat preservation aerogel, and the heating circuit module is arranged above the precision circuit module after the heating circuit module is pasted on the heating circuit heating film belt and wrapped with the heating circuit heat preservation aerogel. The precision circuit module comprises precision circuits of a gravity sensor constant temperature multi-point control self-adjusting circuit and precision circuits of a second and precision circuit board constant temperature temperature measuring circuit, wherein the precision circuits of the gravity sensor constant temperature multi-point control self-adjusting circuit comprise a first operational amplifier circuit, a second operational amplifier circuit, a third operational amplifier circuit, a first single-channel precision instrument operational amplifier, a first 24-bit A / D converter, a double-channel precision instrument operational amplifier and an ARM processor, wherein the output end of the second operational amplifier circuit is connected with the input end of the first single-channel precision instrument operational amplifier, the output end of the first single-channel precision instrument operational amplifier is connected with the input end of the first 24-bit A / D converter, the output end of the first 24-bit A / D converter, the output ends of the first operational amplifier circuit, the second operational amplifier circuit and the third operational amplifier circuit are respectively connected with the input end of the double-channel precision instrument operational amplifier, and the output end of the double-channel precision instrument operational amplifier is connected with the ARM processor. The precision circuits of the second and precision circuit board constant temperature temperature measuring circuit comprise a fourth operational amplifier circuit, a fifth operational amplifier circuit, a second single-channel precision instrument operational amplifier, a third single-channel precision instrument operational amplifier, a second 24-bit A / D converter, a third 24-bit A / D converter and an ARM processor, wherein the fourth operational amplifier circuit is connected with the ARM processor in sequence through the second single-channel precision instrument operational amplifier and the second 24-bit A / D converter, and the fifth operational amplifier circuit is connected with the ARM processor in sequence through the third single-channel precision instrument operational amplifier and the third 24-bit A / D converter.

2. The self-adjusting linear control gravimeter thermostat system of claim 1, wherein: The first subsystem comprises a first upper end heating film belt, a first side wall heating film belt, a first lower end heating film belt, a first subsystem temperature measuring thermistor and a first heat preservation aerogel, graphite heat conduction material is first laid on the outer periphery of the gravity sensor, the first upper end heating film belt, the first side wall heating film belt and the first lower end heating film belt are respectively pasted on the upper end, the side wall and the lower end of the gravity sensor on which the graphite heat conduction material is laid, the gravity sensor on which the heating film belt is pasted is tightly wrapped by the first heat preservation aerogel and arranged inside the second subsystem, and the first subsystem temperature measuring thermistor is arranged on the upper, middle and lower ends of the gravity sensor.

3. The self-adjusting linear control gravimeter thermostat system of claim 1, wherein: The secondary subsystem comprises a shell, a secondary subsystem temperature measuring thermistor, a secondary heating film belt and a secondary thermal insulation aerogel, wherein the shell is in a cylindrical shape, is processed into a cylindrical cylinder by light red copper and has a reserved groove for placing the secondary subsystem temperature measuring thermistor, the shell outer wall is pasted with the secondary heating belt, and the secondary thermal insulation aerogel is used to tightly wrap the secondary heating belt.

4. The self-adaptive linear control gravimeter constant temperature system according to claim 1, characterized in that: The precision circuit module comprises a digital real-time adjustable linear temperature control circuit, and the current control type digital real-time adjustable linear temperature control circuit with the current adjustable function comprises: an ARM processor which inputs a PWM control signal output in real time according to a control algorithm to a PAC module through an optical coupler isolator, linearly converts 0%-100% PWM digital signals into 4-20 mA current output, and drives a heating sheet to work through a current adjustable circuit constructed by a Darlington tube and a current detection type operational amplifier.

5. A method of operating an adaptive linear control gravity meter thermostat system as claimed in any one of claims 1 to 4, characterized in that: The method comprises the following steps: Step 1, constructing a two-stage six-way constant temperature system, taking the enhancement of the constant temperature and uniform temperature effects of the core inertial device as the core, taking into account the temperature drift and heat dissipation characteristics of the electronic device, designing the circuit board constant temperature system into a precision circuit module and a heating circuit module, and adopting a switching temperature control mode for the heating circuit module; Step 2, generating a high-precision reference voltage by using a precision voltage reference chip, constructing a grounded constant current source circuit with a precision instrument operational amplifier and a high-precision metal film resistor, generating a constant current suitable for driving the thermistor to work, and improving the temperature measurement precision, thereby providing a precision temperature measurement basis for high-precision constant temperature control; Step 3, the heating film belts on the side wall, the upper end and the lower end of the cylindrical gravity sensor in the primary constant temperature subsystem are controlled to heat separately, and the real-time temperature values are fed back by the primary subsystem temperature measuring thermistor, so that three-point constant temperature control is realized; the thermistor at the center is taken as a temperature control reference, a temperature-voltage quantity comparison method is adopted, the ARM processor control strategy is used to real-time correct the upper and lower end temperature control values to be consistent with the center end temperature value, the axial temperature gradient difference is greatly reduced, and a temperature field close to equilibrium is created.

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