Signal acquisition and conversion device

Abstract

The utility model provides a signal acquisition and conversion device, which comprises a vehicle-mounted sensor A and a vehicle-mounted sensor B which are used for detecting the obstacle distance of a blind area and have the same model or different models, and after the signal output end of the vehicle-mounted sensor A is connected with a delayer, a delay signal passes through a pre-amplification circuit I; the signal output end of the vehicle-mounted sensor B directly passes through the second pre-amplification circuit, the signal amplification factor of the second pre-amplification circuit is integral multiple of the signal of the first pre-amplification circuit, and the output end of the first pre-amplification circuit and the output end of the second pre-amplification circuit are connected with the two input ends of the subtracter respectively. The two output ends of the subtracter are connected with the low-pass filter circuit, and the output end of the low-pass filter circuit is connected with the vehicle-mounted MCU. According to the scheme, the performance of the signal acquisition and conversion device is effectively improved, the signal acquisition and conversion device has better anti-interference capability, processing precision and adjustment flexibility, and through the design of the pre-amplification circuit and the low-frequency signal extraction module, the signal acquisition and conversion effect is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of equipment signal acquisition, conversion and processing, and in particular relates to a signal acquisition and conversion device. Background Art

[0002] In vehicle driving assistance systems, blind spot monitoring systems are technologies used to help drivers identify other vehicles or objects in the side blind spot. This technology typically uses sensors and signal processing algorithms to monitor the area around the vehicle and provide warnings to reduce potential collision risks. The main goal of a blind spot monitoring system is to improve driving safety and reduce collisions or accidents caused by failure to notice other vehicles or objects in the side blind spot. This system is generally considered an important function in vehicle driving assistance systems, which can effectively help drivers avoid potentially dangerous situations and improve driving comfort and safety. Without a blind spot monitoring function, the driver may not be able to detect other vehicles or objects on the side in time when changing lanes, thereby increasing the risk of collision or scratching with the side vehicle. Vehicles without blind spot monitoring may make drivers feel unsafe and unconfident because they cannot accurately know whether there are potential dangerous situations on the side, which affects driving confidence and performance.

[0003] The current blind spot monitoring system still has some technical challenges and problems, including insufficient monitoring sensitivity, weak discrimination, and easy misjudgment. The sensor technology currently used may have a narrow monitoring range or insufficient monitoring sensitivity for small objects. The performance of the sensor is affected by factors such as its resolution, detection distance, and environmental conditions, and sometimes it may not be able to fully cover the blind spot on the side of the vehicle. The signal processing algorithm is not precise enough to accurately identify low targets such as small vehicles, motorcycles, and bicycles, and may cause missed or false alarms due to noise interference or changes in environmental conditions. The current monitoring system may rely only on a single sensor or a single perception mode for target detection and identification, and lacks the ability to distinguish between comprehensive multi-source information, which may lead to inaccurate judgments for complex scenes.

[0004] Therefore, to solve the technical problems existing in the current blind spot monitoring system, at least further improvements are needed in the hardware terminal to enhance the monitoring sensitivity, discrimination and accuracy. Utility Model Content

[0005] The utility model provides a signal acquisition and conversion device, which aims to solve the signal acquisition and conversion problems in the detection of obstacle distance in the blind spot of a vehicle, and improves the signal processing accuracy and anti-interference ability through components such as preamplifiers and filters, so as to achieve more accurate blind spot detection and improve driving safety.

[0006] The utility model solves the technical problem by adopting a signal acquisition and conversion device, characterized in that it comprises a vehicle-mounted sensor A and a vehicle-mounted sensor B of the same or different models for detecting the distance of obstacles in the blind spot, after the signal output end of the vehicle-mounted sensor A is connected to a delay device, the delayed signal passes through a preamplifier circuit 1; the signal output end of the vehicle-mounted sensor B directly passes through a preamplifier circuit 2, the signal amplification factor of the preamplifier circuit 2 is an integer multiple of the signal of the preamplifier circuit 1, the output ends of the preamplifier circuit 1 and the preamplifier circuit 2 are respectively connected to two input ends of a subtractor, the two output ends of the subtractor are connected to a low-pass filter circuit, and the output end of the low-pass filter circuit is connected to a vehicle-mounted MCU.

[0007] Furthermore, the vehicle-mounted MCU is connected to the REF terminal of the subtractor through a signal line.

[0008] Furthermore, a low-frequency signal extraction module is connected to the output end of the two preamplifier circuits or one of the preamplifier circuits.

[0009] Further, the input signals of the two preamplifier circuits are connected to capacitors C1 and C2 respectively, for receiving weak monitoring signals and amplifying them; the signal input end of the preamplifier circuit 1 is connected to the base of the NPN transistor Q1, the base is grounded through a resistor R1, the collector of the transistor Q1 is connected to the pull-up resistor R2, and is simultaneously connected to the base of the NPN transistor Q2, the collector of the triode Q2 is connected to the pull-up resistor R3, and the output signal is simultaneously transmitted to the first low-frequency signal extraction module. The signal input end of the preamplifier circuit 2 is connected to the base of the NPN transistor Q3, the base is grounded through a resistor R5, the collector of the transistor Q3 is connected to the pull-up resistor R6, and is simultaneously connected to the base of the NPN transistor Q4, the collector of the triode Q4 is connected to the pull-up resistor R7, and the output signal is simultaneously transmitted to the second low-frequency signal extraction module.

[0010] Furthermore, the output end of the first low-frequency signal extraction module is connected in series with a voltage-dividing resistor and is grounded through a capacitor C3, and the output end of the second low-frequency signal extraction module is connected in series with a voltage-dividing resistor and is grounded through a capacitor C4.

[0011] Beneficial effects of the utility model: the solution effectively improves the performance of the signal acquisition and conversion device, making it have better anti-interference ability, processing accuracy and adjustment flexibility, while also taking into account issues such as heat dissipation and cost.

[0012] 1. Improved signal acquisition and conversion effects: Through the design of the preamplifier circuit and the low-frequency signal extraction module, the weak signals output by the vehicle-mounted sensor are effectively amplified and extracted, thereby improving the signal acquisition and conversion effects.

[0013] 2. Improved accuracy: The preamplifier circuit can effectively reduce external interference, so that the interference to the signal during transmission is minimized, thereby improving the stability and reliability of the system. Through the design of the subtractor and low-pass filter, noise and stray signals can be effectively removed and the target signal can be retained, thereby improving the precision and accuracy of signal processing.

[0014] 3. Enhanced adjustment flexibility: By adjusting the REF terminal of the subtractor through the on-board MCU, offset adjustment can be performed, making the system more flexible and adaptable. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the appearance structure of the device of the utility model;

[0016] Figure 2 It is a module relationship block diagram of the utility model;

[0017] Figure 3 The utility model is a circuit principle diagram. DETAILED DESCRIPTION

[0018] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0019] Embodiment 1: A signal acquisition and conversion device, which mainly includes an on-board MCU, an on-board sensor, a preamplifier circuit, a low-frequency signal extraction module, a subtractor and a low-pass filter, and a device housing. Figure 1 As shown, the device housing 7 has data cable and power cable jacks respectively. One or both ends of the device housing 7 are connected to the corresponding jacks by plugging in the data cable 8 to achieve information transmission. One end interface of the device is connected to the corresponding sensor, and the other end interface is connected to the vehicle-mounted MCU. A base 9 is fixedly installed at the lower part of the device housing 7. Heat sinks 10 are distributed on the base 9 to ensure that the bottom support part has a heat dissipation channel. The two ends of the rear side of the base are provided with a card seat 11 for fixed installation in a hidden position of the vehicle body. Figure 3 In the figure, number 1 is a vehicle-mounted dual sensor assembly, number 2 is a delay device, number 3 is a preamplifier circuit, number 4 is a subtractor, number 5 is a low-pass filter, and number 6 is a low-frequency signal extraction module.

[0020] Figure 2In the figure, vehicle sensor A and vehicle sensor B are two sets of sensors of the same or different models used to detect the distance of obstacles in the blind spot. After the signal output end of vehicle sensor A is connected to the delay device, the delayed signal passes through preamplifier circuit 1; the signal output end of vehicle sensor B directly passes through preamplifier circuit 2, and the signal amplification factor of preamplifier circuit 2 is an integer multiple of the signal of preamplifier circuit 1. The output ends of the two preamplifier circuits are respectively connected to the two input ends of the subtractor, and the two output ends of the subtractor are connected to the low-pass filter circuit, and the output end of the low-pass filter circuit is connected to the vehicle MCU.

[0021] In addition, the vehicle-mounted MCU is further connected to the REF terminal of the subtractor through a signal line. In most cases, the vehicle-mounted MCU is not required to provide offset adjustment, but if necessary, the vehicle-mounted MCU can apply a voltage to the REF terminal of the subtractor to perform offset adjustment (provide an offset voltage to the REF pin), which is an optional circuit for fine-tuning the output offset voltage. The voltage applied to the REF terminal by the vehicle-mounted MCU is summed at the output. The subtractor provides low impedance at the REF terminal to maintain good common-mode rejection.

[0022] Specific circuits such as Figure 3 As shown, the signal end in1 of the vehicle sensor A of the same or different models and the signal end in2 of the vehicle sensor B are used to detect the distance of the blind spot obstacle. The delay device can be in various forms. Figure 2 A time delay based on an RC delay circuit is provided, for example, R=470K, C=0.1uF, then the time constant is directly the value of R×C. The preamplifier circuit refers to a circuit or electronic device placed between the signal source and the low-frequency signal extraction module, which is specially designed to receive weak voltage signals from the signal source.

[0023] The input signal of the preamplifier circuit is connected to capacitors C1 and C2 respectively, which are used to receive weak monitoring signals and amplify them. The signal input end of the preamplifier circuit 1 is connected to the base of the NPN transistor Q1, which is grounded through a resistor R1, the collector of the transistor Q1 is connected to the pull-up resistor R2, and is also connected to the base of the NPN transistor Q2, the collector of the triode Q2 is connected to the pull-up resistor R3, and the output signal is transmitted to the first low-frequency signal extraction module at the same time. The signal input end of the preamplifier circuit 2 is connected to the base of the NPN transistor Q3, which is grounded through a resistor R5, the collector of the transistor Q3 is connected to the pull-up resistor R6, and is also connected to the base of the NPN transistor Q4, the collector of the triode Q4 is connected to the pull-up resistor R7, and the output signal is transmitted to the second low-frequency signal extraction module at the same time.

[0024] The above two preamplifier circuits are directly connected to the sensor of the detection signal. The preamplifier circuit amplifies the useless signal while amplifying the useful signal. The purpose of the preamplifier circuit is to make the useless signal coefficient of the circuit reach the minimum value. The preamplifier circuit can effectively reduce external interference, and the signal can be initially amplified by the preamplifier. Both preamplifier circuits are non-adjustable, designed with high input impedance and low output impedance, and provide different amplification adjustment multiples and shaping constants, which are convenient for subsequent adjustment and use.

[0025] The low-frequency signal extraction module has a further amplification function and is used as a compensation amplifier for the preamplifier circuit. In order to amplify the weak signal provided by the monitoring probe, the low-frequency signal extraction module compensation preamplifier circuit must fully consider the interference problem. This circuit connects a CR series circuit ( Figure 2 R20 and C8, R21 and C9 in the middle) are used to resist infection, compensate and amplify the signal.

[0026] Both low-frequency signal extraction modules use OP amplifiers (such as OP27GS). The output end of the first low-frequency signal extraction module is connected in series with a voltage-dividing resistor (R9 and R10) and grounded through capacitor C3. The output end of the second low-frequency signal extraction module is connected in series with a voltage-dividing resistor (R11 and R12) and grounded through capacitor C4. Capacitors C3 and C4 are used to determine the low-frequency cutoff frequency. The frequency range depends on the resistance value obtained after R9 and R11 are divided (R9 is divided by R10, and R11 is divided by R12). At the same time, the above capacitors can also be used to filter out the bias drift of the OP amplifier (such as OP27GS). The gain of the circuit is determined by resistors R10 and R12. In the compensation circuit, high-precision resistors and capacitors must be selected. Resistors with an error of ±1% are relatively easy to obtain, while capacitors must be selected from products with an error of ±5% to make their errors within ±2%. Styrene or polyethylene capacitors are usually more suitable.

[0027] Figure 2 The subtractor in the subtractor is based on operational amplifier U1 such as INA128, INA828, etc. Its reverse input terminal is connected in series with resistor R13, and its forward input terminal is connected in series with resistor R14. R15 is connected in series between the reverse input terminal and the output terminal, and R17 is connected in series between the forward input terminal and REF, satisfying R13=R15, R14=R17. The REF pin is connected by the vehicle MCU or external input voltage V3, so Vo=V1-V2+V3. Usually, the REF pin is connected to the reference voltage collected by the ADC, or a certain offset is added.

[0028] Figure 2The role of the low-pass filter in signal processing is to smooth out the signal by removing short-term fluctuations and retaining the long-term trend. Passive filters or active filters can be used. One type of active low-pass filter is a first-order filter. For example, a gain or suppression amplifier U2 is converted into a low-pass filter by adding capacitor C7. This weakens the frequency response at high frequencies and avoids oscillations inside the amplifier.

[0029] When the above scheme is implemented and used, first, the needs of vehicle blind spot obstacle distance detection are analyzed in detail to determine the signal types, signal processing requirements and system performance indicators that need to be collected and converted. Then, plan the design scheme, determine the required components and their functions, select appropriate vehicle sensors and other components according to the needs, and design hardware circuits, including preamplifier circuits, low-frequency signal extraction modules, subtractors, low-pass filters, etc. In the design process, factors such as circuit stability, anti-interference ability, signal processing accuracy and cost need to be considered, and appropriate components should be selected. According to the design scheme, the circuit is implemented and wired, and the components are connected according to the design. Then, the circuit is debugged, the working status of each part is checked, and the parameters and component values ​​are adjusted to ensure that the circuit works normally and can meet the design requirements. Design and manufacture the device housing to ensure that the circuit and components can be well protected and can be easily installed on the vehicle. Reserve data cable and power cable jacks on the housing, and lay out and design according to actual needs. Assemble the various parts together, perform system integration, and conduct overall testing. The test includes functional testing of signal acquisition and conversion, system stability testing, and testing of anti-interference ability and signal processing accuracy. Ensure that the system can work normally and meet the design requirements. Optimize and improve the system based on test results and user feedback. It may be necessary to adjust circuit parameters, optimize algorithms, or upgrade software and hardware to improve system performance and user experience. After completing the design and debugging of the system, mass production is carried out and the system is deployed in actual vehicles. At the same time, user training and technical support are carried out to ensure that users can use and maintain the system correctly. Through the above implementation process, it can be ensured that the solution can smoothly go from design to actual application and meet user needs and expectations.

[0030] The above specific implementations of the present invention are only used to illustrate or explain the principles of the present invention, and do not constitute a limitation of the present invention. Therefore, any modification, equivalent replacement, improvement, etc. made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention.

Claims

1. A signal acquisition and conversion device, characterized in that: It includes a vehicle-mounted sensor A and a vehicle-mounted sensor B of the same or different models for detecting the distance of obstacles in the blind spot. After the signal output end of the vehicle-mounted sensor A is connected to a delay device, the delayed signal passes through a preamplifier circuit 1; the signal output end of the vehicle-mounted sensor B directly passes through a preamplifier circuit 2, the signal amplification factor of the preamplifier circuit 2 is an integer multiple of the signal of the preamplifier circuit 1, the output ends of the preamplifier circuit 1 and the preamplifier circuit 2 are respectively connected to two input ends of a subtractor, the two output ends of the subtractor are connected to a low-pass filter circuit, and the output end of the low-pass filter circuit is connected to a vehicle-mounted MCU.

2. The signal acquisition and conversion device according to claim 1, characterized in that: The on-board MCU is connected to the REF terminal of the subtractor through a signal line.

3. The signal acquisition and conversion device according to claim 1, characterized in that: A low-frequency signal extraction module is connected to the output end of the two preamplifier circuits or one of the preamplifier circuits.

4. The signal acquisition and conversion device according to claim 1, characterized in that: The input signals of the two preamplifier circuits are connected to capacitors C1 and C2 respectively, which are used to receive weak monitoring signals and amplify them; the signal input end of the preamplifier circuit one is connected to the base of the NPN transistor Q1, the base is grounded through a resistor R1, the collector of the transistor Q1 is connected to the pull-up resistor R2, and is also connected to the base of the NPN transistor Q2, the collector of the triode Q2 is connected to the pull-up resistor R3, and the output signal is transmitted to the first low-frequency signal extraction module at the same time; the signal input end of the preamplifier circuit two is connected to the base of the NPN transistor Q3, the base is grounded through a resistor R5, the collector of the transistor Q3 is connected to the pull-up resistor R6, and is also connected to the base of the NPN transistor Q4, the collector of the triode Q4 is connected to the pull-up resistor R7, and the output signal is transmitted to the second low-frequency signal extraction module at the same time.

5. The signal acquisition and conversion device according to claim 4, characterized in that: The output end of the first low-frequency signal extraction module is connected in series with a voltage-dividing resistor and is grounded through a capacitor C3. The output end of the second low-frequency signal extraction module is connected in series with a voltage-dividing resistor and is grounded through a capacitor C4.

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