Inclination angle detection circuit

Abstract

The invention relates to an inclination angle detection circuit comprising a constant voltage unit used for outputting a constant voltage signal; the constant current unit is used for converting the constant voltage signal into a constant current signal; the acceleration sensor is used for sensing an acceleration signal of the to-be-detected object under the action of the constant current signal and converting the acceleration signal into an electric signal; the acceleration conditioning unit is used for performing amplification, filtering and zero drift suppression processing on the electric signal under the action of the constant current signal to obtain a conditioning signal; and the controller is used for controlling the working state of the constant voltage unit and processing and analyzing the conditioning signal to obtain the inclination angle information of the object to be measured. According to the invention, the overall performance of the circuit is improved through the combination of constant voltage and constant current, and the measurement precision can be improved to + / -0.1 degree; therefore, adverse factors such as power supply fluctuation and environmental interference are effectively resisted in a logging environment, accurate and real-time drill bit inclination angle information is provided, and key data support is provided for accurate guidance, safety monitoring and efficiency improvement of logging operation.

Description

Technical Field

[0001] This invention relates to the field of electronic circuits, and more specifically to a tilt angle detection circuit. Background Technology

[0002] In oil well logging, the wellbore inclination angle is one of the key parameters measured. In recent years, with the rapid development of sensor technology, accelerometers have been widely used in inclination angle detection. The operating current and voltage of the accelerometer are both important factors affecting its operation. If the operating voltage is normal but the operating current is abnormal, it may lead to instability, accelerated aging, and communication failures. Conversely, if the operating current is normal but the operating voltage is abnormal, it may result in measurement errors, instability, and increased risk of damage. Because the environmental conditions of well logging operations are harsh, affecting the stability of the accelerometer's power supply, the detection accuracy is currently poor, with a measurement accuracy of ±0.2 mm of well inclination, which cannot meet the requirements for high precision. Therefore, developing a reliable and high-precision inclination angle detection technology is crucial. Summary of the Invention

[0003] This invention provides a tilt angle detection circuit to solve the problem of low tilt angle detection accuracy.

[0004] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a tilt angle detection circuit, comprising:

[0005] The constant voltage unit is electrically connected to the power supply and is used to output a constant voltage signal under the power supply.

[0006] A constant current unit, electrically connected to the constant voltage unit, is used to convert the constant voltage signal into a constant current signal;

[0007] An accelerometer, electrically connected to the constant current unit, is used to accurately sense the acceleration signal of the object under test under the action of the constant current signal, and convert the acceleration signal into an electrical signal and output it.

[0008] An acceleration conditioning unit is electrically connected to the constant current unit and the acceleration sensor, and is used to amplify, filter and suppress zero-point drift of the electrical signal under the action of the constant current signal to obtain a conditioning signal.

[0009] The controller is electrically connected to the constant pressure unit and the acceleration conditioning unit, and is used to control the working state of the constant pressure unit and to process and analyze the conditioning signal to obtain the tilt angle information of the object under test.

[0010] Based on the above technical solution, the present invention can be further improved as follows.

[0011] Furthermore, the constant voltage unit includes:

[0012] The base of transistor Q2 is connected to the controller through resistor R7, and the collector is connected to the power supply VCC and grounded through capacitor C1.

[0013] Optocoupler U1 has its positive input terminal connected to the emitter of transistor Q2, and its collector output terminal connected to power supply VDD through resistor R4 and grounded through resistor R4 and capacitor C2 in sequence.

[0014] The base of transistor Q1 is connected to the emitter output terminal of optocoupler U1, the collector is connected to power supply VDD through resistor R2, and the emitter is grounded through resistor R3.

[0015] Operational amplifier U2 has its non-inverting input connected to the emitter of transistor Q1, its inverting input connected to its output via resistor R6, and its output connected to the negative input of optocoupler U1 via resistor R5.

[0016] The variable resistor RP1 is connected to the power supply VCC at one end and grounded at the other end. The sliding end is connected to the inverting input terminal of the operational amplifier U2 through the resistor R1 and grounded through the Zener diode D1.

[0017] The emitter of transistor Q1 is the constant voltage signal output terminal of the constant voltage unit and is connected to the constant current unit.

[0018] Furthermore, the constant current unit includes:

[0019] The base of transistor Q3 is connected to the constant voltage signal output terminal of the constant voltage unit through resistor R9, the collector is connected to the constant voltage signal output terminal of the constant voltage unit, and the emitter is grounded through resistor R8.

[0020] Transistor Q4 has its emitter connected to the base of transistor Q3, and its base connected to the emitter of transistor Q3. Its collector is the constant current signal output terminal of the constant current unit and is connected to the power supply terminal of the accelerometer.

[0021] Furthermore, the acceleration conditioning unit includes:

[0022] An amplifier circuit, with its input terminal connected to the electrical signal output terminal of the accelerometer, is used to amplify the electrical signal output by the accelerometer to obtain an amplified electrical signal.

[0023] A zero-point drift suppression circuit, with its input terminal connected to the constant current unit and the output terminal of the amplifier circuit, is used to perform zero-point drift suppression processing on the amplified electrical signal under the action of the constant current signal.

[0024] The filter circuit, with its input terminal connected to the output terminal of the amplifier circuit, is used to filter the amplified electrical signal for zero-point drift suppression to obtain the conditioning signal.

[0025] Furthermore, the amplification circuit includes:

[0026] The non-inverting input of operational amplifier U4 is connected to the electrical signal output of the accelerometer through resistor R10, and the inverting input is grounded through resistor R12 and connected to its output through resistor R11.

[0027] Furthermore, the zero-point drift suppression circuit includes:

[0028] Operational amplifier U5 has its non-inverting input terminal grounded through capacitor C4, its inverting input terminal connected to the inverting input terminal of operational amplifier U4, and its output terminal connected to the output terminal of operational amplifier U4 through capacitor C3.

[0029] The variable resistor RP2 has one end grounded and the other end connected to the constant current signal output terminal of the constant current unit. The sliding end is connected to the non-inverting input terminal of the operational amplifier U5.

[0030] Furthermore, the filtering circuit includes:

[0031] The IN pin of filter U6 is connected to the output of operational amplifier U4 through capacitor C5. The CLK pin is grounded through capacitor C8. The SHDN and VDD pins are connected to a 5V power supply and are both grounded through capacitor C6. The OUT pin is grounded through resistor R13 and capacitor C9 in sequence. The OUT pin outputs the conditioning signal through resistor R13. The OS and COM pins are both grounded through capacitor C7. The GND pin is grounded.

[0032] Furthermore, it also includes a temperature detection unit, which is electrically connected to the constant current unit and the controller, and is used to detect the ambient temperature of the object under test under the action of the constant current signal to obtain a temperature signal;

[0033] The controller is specifically used to perform temperature compensation on the conditioning signal based on the temperature signal, and to process and analyze the temperature-compensated conditioning signal to obtain the tilt angle information of the object under test.

[0034] Furthermore, the temperature detection unit includes:

[0035] Capacitor C11 has one end connected to the constant current signal output terminal of the constant current unit, and the other end grounded.

[0036] Resistor R14, one end of which is connected to the constant current signal output terminal of the constant current unit;

[0037] Resistor R15 has one end connected to the other end of resistor R14, and the other end grounded;

[0038] One end of the thermistor RT is connected to the other end of the resistor R14, and the other end is grounded.

[0039] Resistor R17, one end of which is connected to the constant current signal output terminal of the constant current unit;

[0040] Resistor R18 has one end connected to the other end of resistor R17, and the other end grounded;

[0041] Operational amplifier U7 has its non-inverting input connected to the other end of resistor R14, its inverting input connected to the other end of resistor R17, and its output connected through resistor R16.

[0042] Resistor R19 is connected at one end to the output terminal of the operational amplifier U7, and at the other end to output the temperature signal;

[0043] Resistor R20 has one end connected to the other end of resistor R19, and the other end grounded;

[0044] Resistor R21 is connected at one end to the other end of resistor R19, and at the other end to the constant current signal output terminal of the constant current unit.

[0045] Capacitor C10 is connected in parallel with resistor R20.

[0046] Furthermore, it also includes a communication unit, which is electrically connected to the controller and is used to transmit the tilt angle information to the communication terminal in real time.

[0047] The beneficial effects of this invention are as follows: The tilt angle detection circuit of this invention improves the overall performance of the circuit by combining constant voltage and constant current, which can improve the measurement accuracy to ±0.1°. The constant voltage unit is responsible for converting the unstable input power supply into a constant voltage that meets the working requirements of the accelerometer, ensuring a stable and noise-free power supply for subsequent circuits and eliminating the impact of power fluctuations on sensor performance. The constant current unit converts the constant voltage signal into a constant current to supply the accelerometer. The constant current unit can ensure that the accelerometer receives a consistent current under various working conditions, which helps to maintain the stability of its working performance and measurement accuracy. Therefore, this invention can effectively resist adverse factors such as power fluctuations and environmental interference in the logging environment, providing accurate and real-time drill bit tilt angle information, and providing key data support for accurate guidance, safety monitoring and efficiency improvement of logging operations. Attached Figure Description

[0048] Figure 1 This is an overall structural block diagram of a tilt angle detection circuit according to the present invention;

[0049] Figure 2The circuit schematics are for the constant voltage unit and the constant current unit.

[0050] Figure 3 The circuit schematic for the acceleration conditioning unit;

[0051] Figure 4 This is the circuit schematic of the temperature detection unit. Detailed Implementation

[0052] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0053] like Figure 1 As shown, a tilt angle detection circuit includes:

[0054] The constant voltage unit is electrically connected to the power supply and is used to output a constant voltage signal under the power supply.

[0055] A constant current unit, electrically connected to the constant voltage unit, is used to convert the constant voltage signal into a constant current signal;

[0056] An accelerometer, electrically connected to the constant current unit, is used to accurately sense the acceleration signal of the object under test under the action of the constant current signal, and convert the acceleration signal into an electrical signal and output it.

[0057] An acceleration conditioning unit is electrically connected to the constant current unit and the acceleration sensor, and is used to amplify, filter and suppress zero-point drift of the electrical signal under the action of the constant current signal to obtain a conditioning signal.

[0058] A temperature detection unit, electrically connected to the constant current unit, is used to detect the ambient temperature of the object under test under the action of the constant current signal, and obtain a temperature signal.

[0059] The controller specifically

[0060] The controller is electrically connected to the constant voltage unit, the acceleration conditioning unit, and the temperature detection unit. It is used to perform temperature compensation on the conditioning signal based on the temperature signal, and to process and analyze the temperature-compensated conditioning signal to obtain the tilt angle information of the object under test.

[0061] The communication unit is electrically connected to the controller and is used to transmit the tilt angle information to the communication terminal in real time.

[0062] In oil well logging, accelerometers are installed at key locations on the drill bit to detect changes in its acceleration under gravity in real time. When the drill bit tilts, the accelerometer detects acceleration components in different directions and converts them into electrical signals. This embodiment can use accelerometers suitable for the logging environment, with high precision and strong anti-interference capabilities, such as silicon micromechanical systems (MEMS) accelerometers or high-precision quartz flexible accelerometers, to ensure accurate acceleration measurement even under harsh conditions.

[0063] In practical applications, the logging environment is complex. To obtain accurate drill bit tilt angles, the reliable operation of the accelerometer is crucial. The operating current and voltage of the accelerometer are both critical factors affecting its performance. If the operating voltage is normal but the operating current is abnormal, it may lead to instability, accelerated aging, and communication failures. Conversely, if the operating current is normal but the operating voltage is abnormal, it may result in measurement errors, instability, and increased risk of damage. This invention improves the overall circuit performance by combining a constant voltage unit and a constant current unit. First, the combined application of the constant voltage unit and the constant current unit effectively improves the overall stability of the circuit. The constant voltage unit provides a stable operating voltage for the circuit, while the constant current unit ensures that the accelerometer receives a constant and suitable current supply during operation, effectively avoiding acceleration detection errors caused by power supply voltage fluctuations or current changes, and significantly improving the reliability of the tilt angle detection circuit. Second, through the coordinated work of the constant voltage unit, the constant current unit, the acceleration conditioning unit, and the controller, the tilt angle detection circuit of this invention can effectively resist adverse factors such as power supply fluctuations and environmental interference in the logging environment, providing accurate and real-time drill bit tilt angle information, and providing key data support for accurate guidance, safety monitoring, and efficiency improvement of logging operations.

[0064] Accelerometers are used to convert the acceleration signal of the drill bit into an electrical signal output. However, the electrical signal output by the accelerometer is relatively weak. Due to the complex working environment, there are a lot of interference signals in the electrical signal output by the accelerometer. In order to improve the detection accuracy of acceleration, it is necessary to process the electrical signal output by the accelerometer.

[0065] In this embodiment, the acceleration conditioning unit is used to process the electrical signal output by the acceleration sensor, including:

[0066] Signal amplification: Adjust the gain of weak sensor signals to bring them to a level that is easy for subsequent circuits to process.

[0067] Filtering: Removes noise and unnecessary high-frequency components from electrical signals, improves the signal-to-noise ratio, and ensures the purity of measurement data.

[0068] Zero drift suppression (also known as bias adjustment): Corrects the zero drift of the sensor to ensure the accuracy of the measurement starting point.

[0069] The controller receives the conditioning signal output from the acceleration conditioning unit, performs further data processing and analysis, and calculates the real-time tilt angle of the drill bit based on the acceleration components. The controller also handles the interface connection with the communication unit, packaging the processed data and sending it to the communication terminal via the communication unit.

[0070] The communication unit provides wireless or wired communication interfaces with external communication terminals (such as ground control stations, remote monitoring systems, etc.) to enable real-time data transmission and remote monitoring. The communication unit must possess strong anti-interference capabilities and data encryption functions to ensure the reliability and security of data transmission in the complex electromagnetic environment of the well logging site.

[0071] During well logging operations, the impact of temperature fluctuations on accelerometers is significant due to the complex and variable working environment. To address this issue, the tilt angle detection circuit provided in this embodiment incorporates a temperature detection unit and performs temperature compensation on the conditioning signal, thereby ensuring the accuracy and reliability of tilt angle detection.

[0072] In this embodiment, after receiving the temperature signal from the temperature detection unit, the controller performs temperature compensation processing on the conditioning signal output by the acceleration conditioning unit according to a pre-set temperature compensation algorithm or lookup table method. This is because the performance of the accelerometer (such as sensitivity, zero-point offset, etc.) often changes with temperature. Without compensation, temperature fluctuations may cause deviations in the measurement results.

[0073] In this embodiment, the specific process of temperature compensation may include:

[0074] Model establishment: Based on the temperature characteristic curve of the accelerometer or experimental data, establish a mathematical model between the accelerometer output and temperature.

[0075] Temperature effect parameter calculation: Based on the currently received temperature signal, calculate the effect parameters such as sensitivity drift and zero-point offset that the sensor may produce at this temperature.

[0076] Signal correction: The calculated temperature effect parameters are applied to the conditioning signal processing flow to adjust the gain or offset of the original acceleration signal accordingly, thereby eliminating the effects of temperature changes.

[0077] By adding a temperature detection unit and combining it with the temperature compensation function of the controller, the high-precision tilt angle detection circuit of this embodiment can monitor and respond to the temperature changes of the working environment of the accelerometer in real time, ensuring that the accelerometer can still provide accurate acceleration measurement data in logging environments with large temperature fluctuations, thereby accurately reflecting the tilt state of the drill bit and ensuring the safety and efficiency of logging operations.

[0078] In this embodiment, as Figure 2 As shown, the constant pressure unit includes:

[0079] The base of transistor Q2 is connected to the controller through resistor R7, and the collector is connected to the power supply VCC and grounded through capacitor C1.

[0080] Optocoupler U1 has its positive input terminal connected to the emitter of transistor Q2, and its collector output terminal connected to power supply VDD through resistor R4 and grounded through resistor R4 and capacitor C2 in sequence.

[0081] The base of transistor Q1 is connected to the emitter output terminal of optocoupler U1, the collector is connected to power supply VDD through resistor R2, and the emitter is grounded through resistor R3.

[0082] Operational amplifier U2 has its non-inverting input connected to the emitter of transistor Q1, its inverting input connected to its output via resistor R6, and its output connected to the negative input of optocoupler U1 via resistor R5.

[0083] The variable resistor RP1 is connected to the power supply VCC at one end and grounded at the other end. The sliding end is connected to the inverting input terminal of the operational amplifier U2 through the resistor R1 and grounded through the Zener diode D1.

[0084] The emitter of transistor Q1 is the constant voltage signal output terminal of the constant voltage unit and is connected to the constant current unit.

[0085] The working principle of the constant pressure unit is as follows:

[0086] When logging operations begin, the operator can send control commands to the controller via a communication terminal. Upon receiving the control commands, the controller sends a high-level signal to the base of transistor Q2, causing transistor Q2 to operate in a switching state and conduct. At this time, the voltage at the positive input terminal of optocoupler U1 is greater than the forward voltage of the internal LED of optocoupler U1, causing optocoupler U1 to conduct. The output terminal of optocoupler U1 outputs a high level, and transistor Q1 conducts, operating in an amplification state. After transistor Q1 conducts, a constant voltage signal is generated across resistor R3.

[0087] The variable resistor RP1, Zener diode D1, operational amplifier U2, resistors R6 and R5 constitute the feedback circuit. The feedback circuit is used to collect the voltage across resistor R3, process the collected voltage, and feed it back to the negative input terminal of optocoupler U1. Here, it is necessary to ensure that the voltage difference between the two input terminals of optocoupler U1 is greater than the conduction voltage of the internal LED of optocoupler U1, so that optocoupler U1 is in the conducting state.

[0088] Due to environmental factors, the voltage across resistor R3 may fluctuate. When the voltage across R3 increases, the output voltage of operational amplifier U2 increases, and the voltage difference between the two input terminals of optocoupler U1 decreases. Consequently, the luminous intensity of the LED inside optocoupler U1 is weakened, reducing the base current of transistor Q1. This, in turn, reduces the current flowing through resistor R3, thus decreasing the voltage across R3 and preventing it from increasing. Conversely, when the voltage across R3 decreases, the output voltage of operational amplifier U2 decreases, and the voltage difference between the two input terminals of optocoupler U1 increases. This, in turn, increases the luminous intensity of the LED inside optocoupler U1, increasing the base current of transistor Q1. This, in turn, increases the current flowing through resistor R3, and consequently, increasing the voltage across R3, thus preventing it from decreasing.

[0089] By combining the different components mentioned above, the voltage across resistor R3 can be kept stable, thus achieving a constant voltage effect. The optocoupler U1 also serves as a signal isolation device.

[0090] In this embodiment, as Figure 2 As shown, the constant current unit includes:

[0091] The base of transistor Q3 is connected to the constant voltage signal output terminal of the constant voltage unit through resistor R9, the collector is connected to the constant voltage signal output terminal of the constant voltage unit, and the emitter is grounded through resistor R8.

[0092] Transistor Q4 has its emitter connected to the base of transistor Q3, and its base connected to the emitter of transistor Q3. Its collector is the constant current signal output terminal of the constant current unit and is connected to the power supply terminal of the accelerometer.

[0093] The working principle of the constant current unit is as follows:

[0094] The collector of transistor Q4 provides the operating current for the accelerometer. During operation, the current output from the emitter of transistor Q1 flows through resistor R9 and is applied to the base of transistor Q3, turning on transistor Q3. Then, the current output from the emitter of transistor Q1 flows through transistor Q3 and is applied to resistor R8, simultaneously providing base current for transistor Q4. Subsequently, transistor Q4 turns on, and the current output from the emitter of transistor Q1 flows through resistor R9 and transistor Q4 in sequence to the power supply terminal of the accelerometer.

[0095] If the current flowing through transistor Q4 increases, the base current of transistor Q3 increases, which in turn increases the current flowing through resistor R8, and consequently, the base current of transistor Q4 also increases. This, in turn, controls the collector current flowing through transistor Q4 to decrease. Conversely, if the current flowing through transistor Q4 decreases, the base current of transistor Q3 decreases, which in turn decreases the current flowing through resistor R8, and consequently, the base current of transistor Q4 also decreases. This, in turn, controls the collector current flowing through transistor Q4 to increase. Ultimately, this stabilizes the current supplied to the accelerometer's power supply.

[0096] In this embodiment, as Figure 3 As shown, the acceleration conditioning unit includes:

[0097] An amplifier circuit, with its input terminal connected to the electrical signal output terminal of the accelerometer, is used to amplify the electrical signal output by the accelerometer to obtain an amplified electrical signal.

[0098] A zero-point drift suppression circuit, with its input terminal connected to the constant current unit and the output terminal of the amplifier circuit, is used to perform zero-point drift suppression processing on the amplified electrical signal under the action of the constant current signal.

[0099] The filter circuit, with its input terminal connected to the output terminal of the amplifier circuit, is used to filter the amplified electrical signal for zero-point drift suppression to obtain the conditioning signal.

[0100] Specifically, the amplifier circuit includes:

[0101] The non-inverting input of operational amplifier U4 is connected to the electrical signal output of the accelerometer through resistor R10, and the inverting input is grounded through resistor R12 and connected to its output through resistor R11.

[0102] Specifically, the zero-point drift suppression circuit includes:

[0103] Operational amplifier U5 has its non-inverting input terminal grounded through capacitor C4, its inverting input terminal connected to the inverting input terminal of operational amplifier U4, and its output terminal connected to the output terminal of operational amplifier U4 through capacitor C3.

[0104] The variable resistor RP2 has one end grounded and the other end connected to the constant current signal output terminal of the constant current unit. The sliding end is connected to the non-inverting input terminal of the operational amplifier U5.

[0105] Specifically, the filter circuit includes:

[0106] The IN pin of filter U6 is connected to the output of operational amplifier U4 through capacitor C5. The CLK pin is grounded through capacitor C8. The SHDN and VDD pins are connected to a 5V power supply and are both grounded through capacitor C6. The OUT pin is grounded through resistor R13 and capacitor C9 in sequence. The OUT pin outputs the conditioning signal through resistor R13. The OS and COM pins are both grounded through capacitor C7. The GND pin is grounded.

[0107] The working principle of the acceleration conditioning unit is as follows:

[0108] Taking a piezoelectric accelerometer as an example, the constant current signal output by the constant current unit is applied to the power supply terminal of the accelerometer U3. During operation, the accelerometer U3 is used to convert the acceleration signal into an electrical signal output. Since the electrical signal output by the accelerometer U3 is relatively weak, the amplifier circuit composed of operational amplifier U4 is used to amplify the electrical signal output by the accelerometer U3. The amplified electrical signal is then filtered and sent to the controller.

[0109] To improve the accuracy of acceleration detection, when the accelerometer U3 does not detect an acceleration signal, its output signal should be zero. However, in practical applications, the output signal of the accelerometer U3 is not zero; in this case, the signal generated by the accelerometer U3 is zero-drift. To improve the accuracy of acceleration detection, this embodiment incorporates a zero-drift suppression circuit, with operational amplifier U5 acting as a follower to improve the effectiveness of signal transmission. When no acceleration is detected, the resistance of the variable resistor RP2 is adjusted until the output of operational amplifier U4 is zero.

[0110] Because the electrical signal output by the accelerometer contains a large amount of interference signals, the amplified interference signals may directly overwrite the useful electrical signal, thus affecting the accuracy of acceleration detection. Therefore, this invention introduces a filtering circuit to filter out high-frequency noise signals and environmental noise signals in the electrical signal output by operational amplifier U4, and finally sends the filtered conditioned signal to the controller.

[0111] In this embodiment, as Figure 4 As shown, the temperature detection unit includes:

[0112] Capacitor C11 has one end connected to the constant current signal output terminal of the constant current unit, and the other end grounded.

[0113] Resistor R14, one end of which is connected to the constant current signal output terminal of the constant current unit;

[0114] Resistor R15 has one end connected to the other end of resistor R14, and the other end grounded;

[0115] One end of the thermistor RT is connected to the other end of the resistor R14, and the other end is grounded.

[0116] Resistor R17, one end of which is connected to the constant current signal output terminal of the constant current unit;

[0117] Resistor R18 has one end connected to the other end of resistor R17, and the other end grounded;

[0118] Operational amplifier U7 has its non-inverting input connected to the other end of resistor R14, its inverting input connected to the other end of resistor R17, and its output connected through resistor R16.

[0119] Resistor R19 is connected at one end to the output terminal of the operational amplifier U7, and at the other end to output the temperature signal;

[0120] Resistor R20 has one end connected to the other end of resistor R19, and the other end grounded;

[0121] Resistor R21 is connected at one end to the other end of resistor R19, and at the other end to the constant current signal output terminal of the constant current unit.

[0122] Capacitor C10 is connected in parallel with resistor R20.

[0123] The working principle of the temperature detection unit is as follows:

[0124] Resistors R14, R15, thermistor RT, R17, and R18 form a bridge circuit. The resistance of thermistor RT changes with temperature. Assuming the ambient temperature is 0℃, the bridge is in balance. At this time, the voltages at the non-inverting and inverting inputs of operational amplifier U7 are the same, and operational amplifier U7 outputs 0. During the detection process, if the ambient temperature is greater than 0℃, a voltage difference appears between the two inputs of operational amplifier U7. Operational amplifier U7 acts as an amplification unit, sending the amplified voltage signal to the controller. The controller uses the temperature signal output from the temperature detection unit as a conditioning signal for temperature compensation, further improving the accuracy of the tilt angle detection circuit.

[0125] This invention discloses a tilt angle detection circuit that improves overall circuit performance by combining constant voltage and constant current, enabling measurement accuracy to be increased to ±0.1°. The constant voltage unit converts the unstable input power supply into a constant voltage that meets the operating requirements of the accelerometer, ensuring a stable and noise-free power supply for subsequent circuits and eliminating the impact of power fluctuations on sensor performance. The constant current unit converts the constant voltage signal into a constant current to supply the accelerometer, ensuring that the accelerometer receives a consistent current under various operating conditions, thus helping to maintain the stability of its performance and measurement accuracy. Therefore, this invention can effectively resist adverse factors such as power fluctuations and environmental interference in the logging environment, providing accurate and real-time drill bit tilt angle information, and providing key data support for precise guidance, safety monitoring, and efficiency improvement in logging operations.

[0126] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A tilt angle detection circuit, characterized in that, include: The constant voltage unit is electrically connected to the power supply and is used to output a constant voltage signal under the power supply. A constant current unit, electrically connected to the constant voltage unit, is used to convert the constant voltage signal into a constant current signal; An accelerometer, electrically connected to the constant current unit, is used to accurately sense the acceleration signal of the object under test under the action of the constant current signal, and convert the acceleration signal into an electrical signal and output it. An acceleration conditioning unit is electrically connected to the constant current unit and the acceleration sensor, and is used to amplify, filter and suppress zero-point drift of the electrical signal under the action of the constant current signal to obtain a conditioning signal. The controller is electrically connected to the constant pressure unit and the acceleration conditioning unit, and is used to control the working state of the constant pressure unit and to process and analyze the conditioning signal to obtain the tilt angle information of the object under test.

2. The tilt angle detection circuit according to claim 1, characterized in that, The constant pressure unit includes: The base of transistor Q2 is connected to the controller through resistor R7, and the collector is connected to the power supply VCC and grounded through capacitor C1. Optocoupler U1 has its positive input terminal connected to the emitter of transistor Q2, and its collector output terminal connected to power supply VDD through resistor R4 and grounded through resistor R4 and capacitor C2 in sequence. The base of transistor Q1 is connected to the emitter output terminal of optocoupler U1, the collector is connected to power supply VDD through resistor R2, and the emitter is grounded through resistor R3. Operational amplifier U2 has its non-inverting input connected to the emitter of transistor Q1, its inverting input connected to its output via resistor R6, and its output connected to the negative input of optocoupler U1 via resistor R5. The variable resistor RP1 is connected to the power supply VCC at one end and grounded at the other end. The sliding end is connected to the inverting input terminal of the operational amplifier U2 through the resistor R1 and grounded through the Zener diode D1. The emitter of transistor Q1 is the constant voltage signal output terminal of the constant voltage unit and is connected to the constant current unit.

3. The tilt angle detection circuit according to claim 1, characterized in that, The constant current unit includes: The base of transistor Q3 is connected to the constant voltage signal output terminal of the constant voltage unit through resistor R9, the collector is connected to the constant voltage signal output terminal of the constant voltage unit, and the emitter is grounded through resistor R8. Transistor Q4 has its emitter connected to the base of transistor Q3, and its base connected to the emitter of transistor Q3. Its collector is the constant current signal output terminal of the constant current unit and is connected to the power supply terminal of the accelerometer.

4. The tilt angle detection circuit according to claim 1, characterized in that, The acceleration conditioning unit includes: An amplifier circuit, with its input terminal connected to the electrical signal output terminal of the accelerometer, is used to amplify the electrical signal output by the accelerometer to obtain an amplified electrical signal. A zero-point drift suppression circuit, with its input terminal connected to the constant current unit and the output terminal of the amplifier circuit, is used to perform zero-point drift suppression processing on the amplified electrical signal under the action of the constant current signal. The filter circuit, with its input terminal connected to the output terminal of the amplifier circuit, is used to filter the amplified electrical signal for zero-point drift suppression to obtain the conditioning signal.

5. The tilt angle detection circuit according to claim 4, characterized in that, The amplifier circuit includes: The non-inverting input of operational amplifier U4 is connected to the electrical signal output of the accelerometer through resistor R10, and the inverting input is grounded through resistor R12 and connected to its output through resistor R11.

6. The tilt angle detection circuit according to claim 5, characterized in that, The zero-point drift suppression circuit includes: Operational amplifier U5 has its non-inverting input terminal grounded through capacitor C4, its inverting input terminal connected to the inverting input terminal of operational amplifier U4, and its output terminal connected to the output terminal of operational amplifier U4 through capacitor C3. The variable resistor RP2 has one end grounded and the other end connected to the constant current signal output terminal of the constant current unit. The sliding end is connected to the non-inverting input terminal of the operational amplifier U5.

7. The tilt angle detection circuit according to claim 5, characterized in that, The filtering circuit includes: The IN pin of filter U6 is connected to the output of operational amplifier U4 through capacitor C5. The CLK pin is grounded through capacitor C8. The SHDN and VDD pins are connected to a 5V power supply and are both grounded through capacitor C6. The OUT pin is grounded through resistor R13 and capacitor C9 in sequence. The OUT pin outputs the conditioning signal through resistor R13. The OS and COM pins are both grounded through capacitor C7. The GND pin is grounded.

8. The tilt angle detection circuit according to claim 1, characterized in that, It also includes a temperature detection unit, which is electrically connected to the constant current unit and the controller, and is used to detect the ambient temperature of the object under test under the action of the constant current signal to obtain a temperature signal; The controller is specifically used to perform temperature compensation on the conditioning signal based on the temperature signal, and to process and analyze the temperature-compensated conditioning signal to obtain the tilt angle information of the object under test.

9. The tilt angle detection circuit according to claim 8, characterized in that, The temperature detection unit includes: Capacitor C11 has one end connected to the constant current signal output terminal of the constant current unit, and the other end grounded. Resistor R14, one end of which is connected to the constant current signal output terminal of the constant current unit; Resistor R15 has one end connected to the other end of resistor R14, and the other end grounded; One end of the thermistor RT is connected to the other end of the resistor R14, and the other end is grounded. Resistor R17, one end of which is connected to the constant current signal output terminal of the constant current unit; Resistor R18 has one end connected to the other end of resistor R17, and the other end grounded; Operational amplifier U7 has its non-inverting input connected to the other end of resistor R14, its inverting input connected to the other end of resistor R17, and its output connected through resistor R16. Resistor R19 is connected at one end to the output terminal of the operational amplifier U7, and at the other end to output the temperature signal; Resistor R20 has one end connected to the other end of resistor R19, and the other end grounded; Resistor R21 is connected at one end to the other end of resistor R19, and at the other end to the constant current signal output terminal of the constant current unit. Capacitor C10 is connected in parallel with resistor R20.

10. The tilt angle detection circuit according to claim 1, characterized in that, It also includes a communication unit, which is electrically connected to the controller and is used to transmit the tilt angle information to the communication terminal in real time.

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