CN112539693B

CN112539693B - Automobile body height detection device and method and automobile

Info

Publication number: CN112539693B
Application number: CN202011301446.XA
Authority: CN
Inventors: 刘壬生; 邱东; 周亚生; 魏恒; 陈辉
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2020-11-19
Filing date: 2020-11-19
Publication date: 2021-11-16
Anticipated expiration: 2040-11-19
Also published as: CN112539693A

Abstract

The invention discloses a device and a method for detecting the height of a vehicle body of a vehicle and the vehicle, wherein the device comprises: the sampling unit is used for sampling the time of each charge and discharge of an inductor in the height sensor of the automobile according to a set sampling period to obtain the charge and discharge time as sample data; the control unit is used for determining the maximum data length of a data group formed by the sampling data within a set sampling period and recording the maximum data length as n; and determining an average value of the first m sampled data within the data length; wherein n and m are positive integers, and m is less than or equal to n; taking the difference value between the (m + 1) th sampling data and the average value as a change rate, and determining the effective data length of a data group formed by the sampling data according to the change rate; and determining the height of the automobile body according to the data group of the sampling data corresponding to the effective data length. According to the scheme, the detection precision of the inductive height sensor for measuring the height of the automobile body of the automobile is improved.

Description

Automobile body height detection device and method and automobile

Technical Field

The invention belongs to the technical field of automobiles, and particularly relates to an automobile body height detection device and method of an automobile and an automobile, in particular to a sensor data acquisition device and method based on trend prejudgment and an automobile.

Background

In the related scheme, the height sensor for measuring the height of the vehicle body mainly comprises an inductive type height sensor, a Hall voltage type height sensor and a current type height sensor. Because the signal of the voltage type and current type height sensors is seriously attenuated due to the overlong wiring harness, most of commercial vehicles with longer bodies adopt the inductance type height sensors to measure the height of the bodies.

However, for the inductive height sensor, the measuring range is from several mH to hundreds mH, the inductance variation corresponding to the angle (height) is relatively small, and the sampling precision requirement reaches 0.1mH (about 1-5 per thousand). The reliability of the height sensor data is the basis for directly controlling the height and the posture of the vehicle body, namely the rapid and accurate acquisition of inductance, and the stability and the reliability of the data are very important.

The inductance of the inductance type height sensor is measured with high precision, which is very important for the control of the height of the vehicle body and the design of the posture of the vehicle body, and the rapidity and the accuracy of the sampling and the stability of the acquired data directly determine the control precision. For the measurement of the inductance of the inductive height sensor, the stability of the measurement accuracy and the real-time measurement are often contradictory.

The above is only for the purpose of assisting understanding of the technical aspects of the present invention, and does not represent an admission that the above is prior art.

Disclosure of Invention

The invention aims to provide a device and a method for detecting the height of an automobile body and the automobile, which are used for solving the problems that the stability and the real-time performance of an inductive height sensor for measuring the height of the automobile body cannot be synchronized, the detection precision of the inductive height sensor for measuring the height of the automobile body is influenced, and the effect of improving the detection precision of the inductive height sensor for measuring the height of the automobile body is achieved.

The invention provides a vehicle body height detection device of an automobile, comprising: a sampling unit and a control unit; the sampling unit is configured to sample the time of each charge and discharge of an inductor in the height sensor of the automobile according to a set sampling period to obtain charge and discharge time as sample data; the control unit is configured to determine the maximum data length of a data group formed by the sampling data within a set sampling period, and the maximum data length is recorded as n; and determining an average value of the first m sampled data within the data length; wherein n and m are positive integers, and m is less than or equal to n; taking the difference value between the (m + 1) th sampling data and the average value as a change rate, and determining the effective data length of a data group formed by the sampling data according to the change rate; wherein, the change rate is the ratio of the difference between the m +1 th sample data and the average value to a set sampling period; and determining the height of the automobile body according to the data group of the sampling data corresponding to the effective data length.

In some embodiments, the sampling unit includes: the device comprises a power supply, a reference power supply, a comparison module and an acquisition module; wherein, the sampling unit samples the time of inductance charging and discharging in the height sensor of car every time, includes: under the action of excitation of the power supply, the inductor and the resistor in the inductive height sensor are charged and discharged, the comparison module compares the voltage at two ends of the inductor with the voltage provided by the reference power supply and outputs a comparison result, and the acquisition module acquires the time difference from the time of excitation of the power supply to the time of comparison result output by the comparison module and takes the time difference as the charging and discharging time of the inductor in the inductive height sensor of the automobile.

In some embodiments, the determining, by the control unit, the maximum data length of the data group of the sample data includes: determining the maximum data length of a data group formed by the sampling data according to the following formula:

wherein n is the maximum data length, v is the air spring of the automobile

The height ascending and descending speed, T is the sampling period, i is the current sampling frequency, R_iδ is the weight occupied by the ith sampling data, and δ is the set target allowable deviation value.

In some embodiments, the control unit, determining an average of the first m sample data, comprises: and (4) assigning a set weight to each data in the first m sampling data, and calculating a weighted average value of the first m sampling data.

In some embodiments, the determining, by the control unit, an effective data length of a data group of the sample data according to the change rate includes: determining whether the rate of change is greater than or equal to a first set value; if the change rate is greater than or equal to the first set value, determining that the effective data length of a data group formed by the sampling data is m-1 under the condition that the rising flag of the change rate is 1, and still setting the rising flag of the change rate to be 1; under the condition that the ascending flag of the change rate is not 1, determining that the effective data length of the data group formed by the sampling data is m +1 until the effective data length of the data group formed by the sampling data is n, and still setting the ascending flag of the change rate to be 1; if the change rate is smaller than the first set value, under the condition that the change rate is smaller than or equal to a second set value, if a drop flag of the change rate is 1, determining that the effective data length of the data group formed by the sampling data is m-1 until the effective data length of the data group formed by the sampling data is 1, and still setting the drop of the change rate to 1; if the drop flag of the change rate is not 1, determining that the effective data length of the data group formed by the sampling data is m +1 until the effective data length of the data group formed by the sampling data is n, and still setting the drop flag of the change rate to 1; if the change rate is smaller than the first set value, determining that the effective data length of the data group formed by the sampling data is m +1 under the condition that the change rate is larger than a second set value until the effective data length of the data group formed by the sampling data is n.

In some embodiments, the control unit determines the effective data length of the data group of the sample data according to the change rate, and further includes: under the condition that the effective data length of a data group formed by the sampling data is m-1, eliminating the sampling data of the 1 st time and the sampling data of the 2 nd time from the data group formed by the sampling data, then continuously taking the difference value between the m +2 th sampling data and the average value of the sampling data of the 3 rd time to the m +1 th time as a change rate, and continuously determining the effective data length of the data group formed by the sampling data according to the change rate; under the condition that the effective data length of the data group formed by the sampling data is m +1, adding the sampling data for m +1 times in the data group formed by the sampling data, then determining the average value of the first m +1 sampling data, continuously taking the difference value between the m +2 sampling data and the average value of the first m +1 sampling data as the change rate, and continuously determining the effective data length of the data group formed by the sampling data according to the change rate; under the condition that the effective data length of a data group formed by the sampling data is n, removing the 1 st sampling data from the data group formed by the sampling data, adding the m +1 th sampling data, then determining the average value of the 2 nd sampling data to the m +1 th sampling data, continuously taking the difference value between the m +2 th sampling data and the average value of the 2 nd sampling data to the m +1 th sampling data as a change rate, and continuously determining the effective data length of the data group formed by the sampling data according to the change rate.

In some embodiments, the determining, by the control unit, the body height of the automobile according to the data group of the sampled data corresponding to the effective data length includes: determining an average value of the data group of the sampling data corresponding to the effective data length; and determining the inductance value of the inductive height sensor according to the average value of the data group of the sampling data corresponding to the effective data length, and determining the body height of the automobile according to the inductance value of the inductive height sensor and the length of the connecting rod of the inductive height sensor of the automobile.

In accordance with the above apparatus, a further aspect of the present invention provides an automobile comprising: the vehicle body height detection device of the vehicle is described above.

In accordance with the above-mentioned vehicle, a further aspect of the present invention provides a vehicle body height detecting method, including: sampling the time of each charge and discharge of an inductor in the height sensor of the automobile according to a set sampling period through a sampling unit to obtain the charge and discharge time as sample data; determining the maximum data length of a data group formed by the sampling data within a set sampling period through a control unit, and recording the maximum data length as n; and determining an average value of the first m sampled data within the data length; wherein n and m are positive integers, and m is less than or equal to n; taking the difference value between the (m + 1) th sampling data and the average value as a change rate, and determining the effective data length of a data group formed by the sampling data according to the change rate; wherein, the change rate is the ratio of the difference between the m +1 th sample data and the average value to a set sampling period; and determining the height of the automobile body according to the data group of the sampling data corresponding to the effective data length.

In some embodiments, the sampling unit includes: the device comprises a power supply, a reference power supply, a comparison module and an acquisition module; wherein, through the sampling unit, to the inductance is the time of charging and discharging at every turn in the height sensor of car samples, includes: under the action of excitation of the power supply, the inductor and the resistor in the inductive height sensor are charged and discharged, the comparison module compares the voltage at two ends of the inductor with the voltage provided by the reference power supply and outputs a comparison result, and the acquisition module acquires the time difference from the time of excitation of the power supply to the time of comparison result output by the comparison module and takes the time difference as the charging and discharging time of the inductor in the inductive height sensor of the automobile.

In some embodiments, determining, by the control unit, a maximum data length of a data group of the sample data includes: determining the maximum data length of a data group formed by the sampling data according to the following formula:

wherein n is the maximum data length, v is the speed of the air spring height of the automobile, T is the sampling period, i is the current sampling frequency, R_iδ is the weight occupied by the ith sampling data, and δ is the set target allowable deviation value.

In some embodiments, determining, by the control unit, an average of the first m sample data comprises: and (4) assigning a set weight to each data in the first m sampling data, and calculating a weighted average value of the first m sampling data.

In some embodiments, determining, by the control unit, an effective data length of the data group of the sample data according to the change rate includes: determining whether the rate of change is greater than or equal to a first set value; if the change rate is greater than or equal to the first set value, determining that the effective data length of a data group formed by the sampling data is m-1 under the condition that the rising flag of the change rate is 1, and still setting the rising flag of the change rate to be 1; under the condition that the ascending flag of the change rate is not 1, determining that the effective data length of the data group formed by the sampling data is m +1 until the effective data length of the data group formed by the sampling data is n, and still setting the ascending flag of the change rate to be 1; if the change rate is smaller than the first set value, under the condition that the change rate is smaller than or equal to a second set value, if a drop flag of the change rate is 1, determining that the effective data length of the data group formed by the sampling data is m-1 until the effective data length of the data group formed by the sampling data is 1, and still setting the drop of the change rate to 1; if the drop flag of the change rate is not 1, determining that the effective data length of the data group formed by the sampling data is m +1 until the effective data length of the data group formed by the sampling data is n, and still setting the drop flag of the change rate to 1; if the change rate is smaller than the first set value, determining that the effective data length of the data group formed by the sampling data is m +1 under the condition that the change rate is larger than a second set value until the effective data length of the data group formed by the sampling data is n.

In some embodiments, determining, by the control unit, an effective data length of a data group formed by the sample data according to the change rate further includes: under the condition that the effective data length of a data group formed by the sampling data is m-1, eliminating the sampling data of the 1 st time and the sampling data of the 2 nd time from the data group formed by the sampling data, then continuously taking the difference value between the m +2 th sampling data and the average value of the sampling data of the 3 rd time to the m +1 th time as a change rate, and continuously determining the effective data length of the data group formed by the sampling data according to the change rate; under the condition that the effective data length of the data group formed by the sampling data is m +1, adding the sampling data for m +1 times in the data group formed by the sampling data, then determining the average value of the first m +1 sampling data, continuously taking the difference value between the m +2 sampling data and the average value of the first m +1 sampling data as the change rate, and continuously determining the effective data length of the data group formed by the sampling data according to the change rate; under the condition that the effective data length of a data group formed by the sampling data is n, removing the 1 st sampling data from the data group formed by the sampling data, adding the m +1 th sampling data, then determining the average value of the 2 nd sampling data to the m +1 th sampling data, continuously taking the difference value between the m +2 th sampling data and the average value of the 2 nd sampling data to the m +1 th sampling data as a change rate, and continuously determining the effective data length of the data group formed by the sampling data according to the change rate.

In some embodiments, determining, by the control unit, a body height of the automobile according to the data set of the sampling data corresponding to the effective data length includes: determining an average value of the data group of the sampling data corresponding to the effective data length; and determining the inductance value of the inductive height sensor according to the average value of the data group of the sampling data corresponding to the effective data length, and determining the body height of the automobile according to the inductance value of the inductive height sensor and the length of the connecting rod of the inductive height sensor of the automobile.

Therefore, according to the scheme of the invention, different charging and discharging times of different inductance values are acquired through the charging constant circuit based on the measured voltage, and the small variation of the inductance values is captured to be used as the acquired data; filtering the acquired data by adopting a data length self-adaptive array type weighted average method in combination with the change condition of the height of the electric control air suspension; the self-adaptive control of real-time performance and stability is carried out on the measurement data of the inductive height sensor for measuring the height of the automobile body through the change rate between the collection data obtained by the m +1 th sampling and the average collection data of the collection data obtained by the previous m times of sampling, and the detection precision of the inductive height sensor for measuring the height of the automobile body is improved.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.

Drawings

Fig. 1 is a schematic structural view of an embodiment of a body height detecting apparatus of an automobile according to the present invention;

FIG. 2 is a schematic structural diagram of an electrically controlled air suspension, specifically a side view of a vehicle, according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of an embodiment of a sampling circuit;

FIG. 4 is a schematic diagram of an embodiment of a sampling circuit;

FIG. 5 is a schematic flow chart of an adaptive data length algorithm, specifically, an adaptive data length algorithm flow chart taking a slope as an example;

FIG. 6 is a data scale diagram of a queued weighted average data processing;

FIG. 7 is a schematic flow chart illustrating an embodiment of a method for detecting a body height of a vehicle according to the present invention;

FIG. 8 is a flowchart illustrating an embodiment of determining an effective data length of a data group of the sampled data according to the change rate in the method of the present invention;

fig. 9 is a schematic flow chart of an embodiment of determining the body height of the vehicle in the method of the present invention.

The reference numbers in the embodiments of the present invention are as follows, in combination with the accompanying drawings:

1-a vehicle frame; 2-wheel support; 3-vehicle wheels; 4-an air spring; 5-a shock absorber; 6-a height sensor; 7-a height sensor connection rod; 8-an electromagnetic valve; 9-a gas storage tank; 10-height Control Unit ECU (Electronic Control Unit); 11-gas path; 12-signal lines.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the specific embodiments of the present invention and the accompanying drawings. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

According to an embodiment of the present invention, there is provided a body height detecting apparatus of an automobile. Referring to fig. 1, a schematic diagram of an embodiment of the apparatus of the present invention is shown. The body height detecting apparatus of the automobile may include: a sampling unit and a control unit.

The sampling unit is configured to sample the time of each charging and discharging of an inductor in the height sensor of the automobile according to a set sampling period to obtain charging and discharging time as sample data.

In some embodiments, the sampling unit includes: the system comprises a power supply, a reference power supply, a comparison module and an acquisition module (such as a main IC chip); the positive pole of the power supply is connected to the first input end of the comparison module through a resistor R in the inductive height sensor, the negative pole of the power supply and the negative pole of the reference power supply are connected to the first input end of the comparison module through an inductor L in the inductive height sensor, the positive pole of the reference power supply is connected to the second input end of the comparison module, and the output end of the comparison module is connected to the acquisition module.

Specifically, the signal acquisition module is composed of an acquisition module (such as a main IC chip) and a peripheral circuit thereof; a comparator module comprising a comparator, a RL circuit comprising a resistor and an inductor, wherein the voltage U of the power supply source₁And a comparison voltage U used as a reference power supply₂Voltage of power supply U₁Voltage U higher than reference power supply₂。

Wherein, the sampling unit samples the time of inductance charging and discharging in the height sensor of car every time, includes: under the action of excitation of the power supply, the inductor and the resistor in the inductive height sensor are charged and discharged, the comparison module compares the voltage at two ends of the inductor with the voltage provided by the reference power supply and outputs a comparison result, and the acquisition module acquires the time difference from the time of excitation of the power supply to the time of comparison result output by the comparison module and takes the time difference as the charging and discharging time of the inductor in the inductive height sensor of the automobile.

Specifically, the power supply source U₁Given a step signal, under the action of the excitation, the response voltage at two ends of the inductor in the RL loop is matched

The case (1). By adopting the method, different charging and discharging time of different inductance values can be captured quickly, so that the difference of small change of the inductance values is obtained, but the situation that the charging time fluctuates up and down at the moment of voltage comparison of the comparison module due to certain jitter of circuit voltage is caused, and therefore jitter elimination and filtering processing of software is required to be carried out on collected data.

The control unit is configured to determine the maximum data length of a data group formed by the sampling data within a set sampling period, and the maximum data length is recorded as n; and determining an average value of the first m sampled data within the data length; wherein n and m are positive integers, and m is less than or equal to n.

In some embodiments, the determining, by the control unit, the maximum data length of the data group of the sample data includes: the control unit is specifically further configured to determine a maximum data length of a data group formed by the sample data according to the following formula:

wherein n is the maximum data length, v is the air bullet of the automobileThe spring height ascending and descending speed, T is the sampling period, i is the current sampling frequency, R_iδ is the weight occupied by the ith sampling data, and δ is the set target allowable deviation value.

Specifically, due to the adoption of a data processing method of a weighted average value, if an array participating in calculation is too long, namely n is too large, data is distorted, and height sensor data cannot be reflected in time, so that control delay is caused; therefore, the maximum value range of n is considered. According to the example shown in fig. 2, when the control unit ECU charges and discharges the air spring by turning on and off the solenoid valve, the speed v of the vehicle height (i.e. the air spring height) is related to the on-off time (i.e. the duty ratio) of the solenoid valve, and when the main IC chip performs data sampling in the period of T and the length of the array data is n, the calculated data is delayed by

Therefore, the maximum value of the data length n is required to satisfy the requirement of setting the target allowable deviation value δ

The method is obtained according to the characteristics of the system such as the suspension, the air spring and the like and the target allowable deviation. Wherein v is the lifting speed of the vehicle body height (namely the air spring height), T is the sampling period, i is the current sampling frequency, n is the data length, R_iδ is the weight occupied by the ith sampling data, and δ is the set target allowable deviation value.

Therefore, by combining the precision requirement required by the height of the vehicle body and the control speed of the air spring, the length of the sampling array participating in calculation is automatically adjusted, and the precision and the speed of the height adjustment of the vehicle body are controllable.

In some embodiments, the control unit, determining an average of the first m sample data, comprises: the control unit is specifically configured to assign a set weight to each of the first m pieces of sample data, and calculate a weighted average of the first m pieces of sample data.

Specifically, in the data processing mode of the queue-type weighted average with the self-adaptive data length, the sampling module acquires data regularly or irregularly, the IC chip arranges the data in the queue-type sequence according to the sampling time, n (n is a natural number, and n is more than or equal to 1) newly sampled samples are used, and then each data is assigned with a certain weight to calculate the weighted value.

Such as: collecting usage data D₁～D_n，D_nFor the latest data acquisition, the weight occupied by the n data is distributed as R₁～R_nWherein R is₁+R₂+..R_n+..+R _n1 and R₁≤R₂≤..R_n≤..≤R_nAnd finally obtaining filtering data:

in this algorithm, the value of the array n is variable, increasing or decreasing adaptively, depending on the value of the height sensor.

The control unit is further configured to determine a change rate between the (m + 1) th sampling data and the average value, namely, a difference value between the (m + 1) th sampling data and the average value is used as the change rate, and determine an effective data length of a data group formed by the sampling data according to the change rate; wherein, the change rate is a ratio of a difference value between the m +1 th sample data and the average value to a set sampling period.

Specifically, after the system starts operating, the main IC chip uses m values (D) of the latest data₁～D_mM is less than or equal to n), and calculating the average value of the array

When the main IC chip collects new data of the height sensor, the data change rate (such as the slope k) is calculated_m+1) And judging whether the height has an ascending or descending trend according to the change rate.

In some embodiments, the determining, by the control unit, an effective data length of a data group of the sample data according to the change rate includes:

the control unit is specifically further configured to determine whether the rate of change is greater than or equal to a first set value.

The control unit is specifically further configured to determine if the change rate is greater than or equal to the first set value (e.g., K)_set1) If the rising flag of the change rate is 1, determining that the effective data length of the data group formed by the sampling data is m-1 (i.e. m +1-2), and still setting the rising flag of the change rate to 1; and under the condition that the ascending flag of the change rate is not 1, determining that the effective data length of the data group formed by the sampling data is m +1 until the effective data length of the data group formed by the sampling data is n, and still setting the ascending flag of the change rate to be 1.

Specifically, when the new data positive change rate is large (slope k)_m+1≥K_set1) When the UP flag UP is 1; when the new data positive change rate is judged to be large continuously twice, namely the height is judged to have the rising trend, the length of the calculation array is shortened, and the rising change of the height can be responded quickly. Such as the rate of change k between the weighted average of the m +1 th data and the previous m data_m+1Is greater than or equal to a set value K_set1When the rising flag of the change rate is 1, the data length is shortened from L ═ m to L ═ m +1-2, and then the rising flag of the change rate is still set to 1; if the increase flag of the change rate is not 1, the data length L is set to m +1 until L is set to n, and then the increase flag of the change rate is set to 1.

The control unit is specifically further configured to determine that the change rate is less than or equal to a second set value (e.g., K) if the change rate is less than the first set value_set2) If the drop flag of the change rate is 1, determining that the effective data length of the data group formed by the sampling data is m-1 until the effective data length of the data group formed by the sampling data is 1, and still setting the drop of the change rate to 1; if the drop flag of the change rate is not 1, determining that the effective data length of the data group formed by the sampling data is m +1 until the effective data length of the data group formed by the sampling data is n, and still setting the drop flag of the change rate to 1.

Specifically, when the new data negative change rate is large (slope k)_m+1≤K_set2) When the current time is up, the DOWN flag is 1; when the new data negative change rate is judged to be large continuously twice, namely the judgment height has a descending trend, the calculation array length is shortened, so that the descending change of the height can be responded quickly. Such as the rate of change k between the weighted average of the m +1 th data and the previous m data_m+1Less than a set value K_set1In the case of (1), if the rate of change k between the weighted average of the m +1 th data and the m previous data_m+1Is less than or equal to a set value K_set2If the drop flag of the change rate is 1, the data length is shortened from L ═ m to L ═ m +1-2 until L ═ 1, and then the drop flag of the change rate is still set to 1; when the decrease flag of the change rate is not 1, the data length L is set to m +1 until L is set to n, and thereafter the decrease flag of the change rate is set to 1.

The control unit is specifically further configured to determine that the effective data length of the data group of the sample data is m +1 until the effective data length of the data group of the sample data is n if the change rate is smaller than the first set value and is larger than a second set value.

Specifically, when the new data change rate is small (slope K)_set2≤k_m+1≤K_set1) When the height is judged to have no ascending or descending trend, the array D is normally counted₁～D_m+1Up to n data samples (if m + 1)>n, then according to the queue mode, D₁～D_nUpdate of data of to D₂～D_m+1(ii) a ) UP is 0 and DOWN is 0 in order to eliminate jitter introduced by the circuit. Such as the rate of change k between the weighted average of the m +1 th data and the previous m data_m+1Less than a set value K_set1In the case of (1), if the rate of change k between the weighted average of the m +1 th data and the m previous data_m+1Greater than a set value K_set2Then, the data length L is equal to m +1 until L is equal to n.

Therefore, the acquired data can be subjected to jitter elimination, the self-adaptive switching control of the precision and stability of data acquisition is realized, and the stability can be effectively improved while the timeliness of the acquired data is not influenced.

In some embodiments, the control unit determines the effective data length of the data group formed by the sampling data according to the change rate, and further includes any one of the following cyclic control processes:

the first cycle control process: the control unit is specifically further configured to, in a case where an effective data length of a data group formed by the sample data is m-1, remove the sample data of the 1 st time and the sample data of the 2 nd time from the data group formed by the sample data, then continue to use a difference value between the m +2 th sample data and an average value of the sample data of the 3 rd time to the m +1 th time as a change rate, and continue to determine the effective data length of the data group formed by the sample data according to the change rate; wherein, the change rate is a ratio of a difference value between the m +1 th sample data and the average value to a set sampling period.

And a second cyclic control process: the control unit is specifically further configured to, when the effective data length of the data group of the sample data is m +1, add the sample data of the m +1 th time to the data group of the sample data, determine an average value of the first m +1 sample data, continue to use a difference value between the m +2 th sample data and the average value of the first m +1 sample data as a change rate, and continue to determine the effective data length of the data group of the sample data according to the change rate.

The third circulation control process: the control unit is specifically configured to, when the effective data length of the data group formed by the sample data is n, remove the sample data of the 1 st time and add the sample data of the m +1 th time in the data group formed by the sample data, then determine an average value of the 2 nd sample data to the m +1 th sample data, continue to use a difference value between the m +2 th sample data and the average value of the 2 nd sample data to the m +1 th sample data as a change rate, and continue to determine the effective data length of the data group formed by the sample data according to the change rate.

Specifically, after the main IC chip collects new data of the height sensor, the data change rate is calculated, whether the height has an ascending trend or a descending trend is judged according to the change rate, and the cycle execution is carried out. When the height sensor is in a static state or fluctuates in a small range, the value of n is relatively large, and the stability of data is guaranteed; when the height sensor is in dynamic change and the height is judged to rise and fall, the value of n is correspondingly reduced, and the quick response to the height change is achieved.

The control unit is further configured to determine the body height of the automobile according to the effective data length of a data group formed by the sampling data and the data group of the sampling data corresponding to the effective data length.

Specifically, by improving inductance measurement, a hardware circuit is adopted for sampling and a data filtering mode is combined, so that the detection precision of the inductance measurement of the circuit is improved, and self-adaptive control is realized in the process of acquiring, processing and guaranteeing the real-time performance of data and improving the stability of the data.

In some embodiments, the determining, by the control unit, the body height of the automobile according to the data group of the sampled data corresponding to the effective data length includes:

the control unit is specifically further configured to determine an average value of the data group of the sampling data corresponding to the effective data length.

The control unit is specifically further configured to determine an inductance value of the inductive height sensor according to an average value of the data group of the sampling data corresponding to the effective data length, and determine a body height of the automobile according to the inductance value of the inductive height sensor and a length of a connecting rod of the inductive height sensor of the automobile.

Specifically, after the main IC chip collects new data of the height sensor, the data change rate is calculated, whether the height has an ascending trend or a descending trend is judged according to the change rate, and the sample length is calculated. After the sample number length is calculated, an array with self-adaptive data length can be obtained.

Due to the voltage U of the power supply₁Voltage U higher than reference power supply₂During the fall of the inductor voltage U (t), the voltage value can cross the comparison voltage U₂. When U (t) is equal to U₂During the process, an inverse level can be output through the comparison module, and after the acquisition module captures the signal, the time t from the beginning of excitation to the output of the inverse level of the comparison module is calculated₁That is to say have

Where R is the resistance of the circuit, t₁Is the time of acquisition of the main IC, U₁、U₂The inductance L can be obtained by designing the voltage.

In some examples, according to the automobile body height detection scheme provided by the scheme of the invention, the time of each charge and discharge of the inductor in the automobile height sensor can be sampled according to a set sampling period to obtain charge and discharge time as sample data; determining effective sample data according to the set detection precision (such as a set target allowable deviation value delta) of the body height of the automobile, the control speed (such as the speed v of the height rise and fall of the air spring of the automobile) of the automobile and the change rate between the sample data obtained by the m +1 th sampling and the average value of the sample data obtained by the m previous samplings; determining the height of the automobile body according to the effective sample data; wherein m is a positive integer.

Optionally, determining valid sample data may include: according to the set detection precision of the height of the automobile body and the control speed of an air spring of the automobile, preliminarily determining the sampling times of sampling the charging time of an inductor in a height sensor of the automobile as initial sample data length (such as the maximum data length n of a data group formed by the sampling data); according to the sample data obtained by sampling each time, adjusting the length of the initial sample data to obtain the length of effective sample data (namely the effective data length); and determining the average value of each sample data in the effective sample data length as effective sample data.

Wherein, according to the sample data obtained by each sampling, adjusting the length of the initial sample data comprises: under the condition that the current sampling times are m, obtaining a weighted average value of m sample data to obtain an average value; m is a positive integer and is less than or equal to the initial sample data length; acquiring the (m + 1) th sample data, determining the change rate between the (m + 1) th sample data and the average sample data, and adjusting the length of the initial sample data according to the change rate and a set value; wherein, the change rate is a ratio of a difference value between the m +1 th sample data and the average sample data to a set sampling period.

Optionally, determining the body height of the automobile may include: determining inductance of inductance in the height sensor according to the effective sample data; and determining the height of the automobile body according to the inductance value and the length of the connecting rod of the height sensor of the automobile.

The inductance value corresponds to the angle of the inductive height sensor, and the angle, in combination with the length of the connecting rod (i.e., the swing link), determines the height of the vehicle body.

Through a large number of tests, the technical scheme of the invention is adopted, different charging and discharging times of different inductance values are collected through a charging constant circuit based on measured voltage, and tiny variation of the inductance values is captured to be used as collected data; filtering the acquired data by adopting a data length self-adaptive array type weighted average method in combination with the change condition of the height of the electric control air suspension; the self-adaptive control of real-time performance and stability is carried out on the measurement data of the inductive height sensor for measuring the height of the automobile body through the change rate between the collection data obtained by the m +1 th sampling and the average collection data of the collection data obtained by the previous m times of sampling, and the detection precision of the inductive height sensor for measuring the height of the automobile body is improved.

According to an embodiment of the present invention, there is also provided an automobile corresponding to the body height detection device of the automobile. The automobile may include: the vehicle body height detection device of the vehicle is described above.

In some embodiments, the present invention provides an adaptive acquisition scheme for an inductive height sensor, which can improve the detection accuracy of the inductance of a circuit by combining a hardware circuit with a data filtering method for improving the inductance measurement, and implement adaptive control in ensuring real-time data acquisition and processing and improving data stability.

In the scheme of the invention, a hardware circuit of the sampling circuit adopts the principle of inductive charging and discharging, combines the calculation of a software data filtering algorithm, and can adopt the measurement of a voltage charging constant according to the principle of the circuit on inductive charging and discharging so as to achieve the purpose of rapidly and accurately measuring the inductance; the jitter of the acquired data can be eliminated, the self-adaptive switching control of the precision and the stability of data acquisition is realized, and the stability can be effectively improved while the timeliness of the acquired data is not influenced; the length of the sampling array participating in calculation can be automatically adjusted by combining the precision requirement required by the height of the vehicle body and the control speed of the air spring, so that the precision and the speed of the height adjustment of the vehicle body can be controlled.

For data measurement of the inductive height sensor, the scheme of the invention provides a method for rapidly acquiring different charging and discharging times of different inductance values and capturing small variation of the inductance values based on a circuit for measuring a voltage charging constant; the method combines the change condition of the height of the electric control air suspension, adopts a queue type weighted average method with self-adaptive data length to filter the collected data, achieves the rapidity of collecting inductance data, and can also achieve the effect of effectively improving the stability of the data.

The following describes an exemplary implementation process of the scheme of the present invention with reference to the examples shown in fig. 2 to fig. 6.

Fig. 2 is a schematic structural diagram of an electrically controlled air suspension according to an embodiment of the present invention, specifically, a side view of a vehicle. As shown in fig. 2, an electronically controlled air suspension for an automobile, includes: the device comprises a frame 1, a wheel bracket 2, wheels 3, an air spring 4, a shock absorber 5, a height sensor 6, a height sensor connecting rod 7, an electromagnetic valve 8, an air storage tank 9, a height control unit ECU 10, an air circuit 11 and a signal circuit 12.

Fig. 3 is a schematic structural diagram of an embodiment of a sampling circuit.

As shown in fig. 3, the signal acquisition module mainly comprises three parts, wherein the first part mainly comprises an acquisition module (such as a main IC chip) and a peripheral circuit thereof; the second part is a comparison module composed of a comparator and the like, the third part is an RL circuit composed of a resistor and an inductor, wherein the voltage U of the power supply source₁And a comparison voltage U used as a reference power supply₂Voltage of power supply U₁Voltage U higher than reference power supply₂。

The height sensor 6, the height sensor link 7 and the height control unit ECU 10 in fig. 2 are devices for detecting the height of the vehicle body, wherein the height control unit ECU 10 covers the acquisition module, the comparison module and the control parts of the power supplies U1, U2 in fig. 3, and the height sensor 6 is the inductance L part in fig. 3. The array type weighted average filtering algorithm with the self-adaptive effective data length carries out self-adaptive filtering on the sampling data of the inductive height sensor in timeliness and stability, and further guarantees the reliable operation and control of an air suspension system.

Power supply U₁Given a step signal, under the action of the excitation, the response voltage at two ends of the inductor in the RL loop is matched

The case (1).

Fig. 4 is a schematic diagram of an operation principle of an embodiment of the sampling circuit.

As shown in fig. 4, due to the voltage U of the power supply source₁Voltage U higher than reference power supply₂During the fall of the inductor voltage U (t), the voltage value can cross the comparison voltage U₂. When U (t) is equal to U₂During the process, an inverse level can be output through the comparison module, and after the acquisition module captures the signal, the time t from the beginning of excitation to the output of the inverse level of the comparison module is calculated₁That is to say have

The voltage drop of the inductor is that in the charging and discharging process, under the charging of the step signal, the voltage at two ends of the inductor jumps to high voltage first and then drops along the exponential change of the RL circuit.

By adopting the method, different charging and discharging time of different inductance values can be captured quickly, so that the difference of small change of the inductance values is obtained, but the situation that the charging time fluctuates up and down at the moment of voltage comparison of the comparison module due to certain jitter of circuit voltage is caused, and therefore jitter elimination and filtering processing of software is required to be carried out on collected data. There may be jitter in the discharge time, but the IC does not handle the inductive discharge period.

FIG. 6 is a data scale diagram of the processing of the queued weighted average data.

The scheme of the invention provides a data processing mode of queue type weighted average with self-adaptive data length, as shown in fig. 6, a sampling module acquires data regularly or irregularly, an IC chip arranges the data in sequence according to sampling time, n (n is a natural number, and n is more than or equal to 1) samples sampled newly are used, and each data is assigned with a certain weight to calculate a weighted value.

When the height sensor is in a static state or fluctuates in a small range, the value of n is relatively large, and the stability of data is guaranteed; when the height sensor is in dynamic change and the height is judged to rise and fall, the value of n is correspondingly reduced, and the quick response to the height change is achieved.

Due to the adoption of a data processing method of a weighted average value, if an array participating in calculation is too long, namely n is too large, data can be distorted, and height sensor data cannot be reflected in time, so that control delay is caused; therefore, the maximum value range of n is considered. According to the example shown in fig. 2, when the control unit ECU charges and discharges the air spring by turning on and off the solenoid valve, the speed v of the vehicle height (i.e. the air spring height) is related to the on-off time (i.e. the duty ratio) of the solenoid valve, and when the main IC chip performs data sampling in the period of T and the length of the array data is n, the calculated data is delayed by

The method is obtained according to the characteristics of the system such as the suspension, the air spring and the like and the target allowable deviation.

Wherein v is the lifting speed of the vehicle body height (namely the air spring height), T is the sampling period, i is the current sampling frequency, n is the data length, R_iδ is the weight occupied by the ith sampling data, and δ is the set target allowable deviation value.

Fig. 5 is a schematic flow chart of the adaptive data length algorithm, specifically, a schematic flow chart of the adaptive data length algorithm taking a slope as an example. As shown in fig. 5, the flow of the adaptive data length algorithm may include:

step 1, after the system starts working, the main IC chip uses m values (D) of the latest data₁～D_mM is less than or equal to n), and calculating the average value of the array

Step 2, after the main IC chip collects new data of the height sensor, calculating a data change rate (the change rate includes, but is not limited to, a slope, a differential, a derivative, etc., and the following example is given by taking the slope as a change degree to perform an exemplary explanation), and determining whether the height has an ascending or descending trend according to the change rate:

alternatively, when the new data positive change rate is large (slope k)_m+1≥K_set1) When the UP flag UP is 1; when the new data positive change rate is judged to be large continuously twice, namely the height is judged to have the rising trend, the length of the calculation array is shortened, and the rising change of the height can be responded quickly.

Specifically, the rate of change k between the weighted average of the m +1 th data and the previous m data_m+1Is greater than or equal to a set value K_set1When the rising flag of the change rate is 1, the data length is shortened from L ═ m to L ═ m +1-2, and then the rising flag of the change rate is still set to 1; if the increase flag of the change rate is not 1, the data length L is set to m +1 until L is set to n, and then the increase flag of the change rate is set to 1.

Alternatively, when the new data negative rate of change is large (slope k)_m+1≤K_set2) When the current time is up, the DOWN flag is 1; when the new data negative change rate is judged to be large continuously twice, namely the judgment height has a descending trend, the calculation array length is shortened, so that the descending change of the height can be responded quickly.

Specifically, the rate of change k between the weighted average of the m +1 th data and the previous m data_m+1Less than a set value K_set1In the case of (1), if the rate of change k between the weighted average of the m +1 th data and the m previous data_m+1Is less than or equal to a set value K_set2If the drop flag of the change rate is 1, the data length is shortened from L ═ m to L ═ m +1-2 until L ═ 1, and then the drop flag of the change rate is still set to 1; when the decrease flag of the change rate is not 1, the data length L is set to m +1 until L is set to n, and thereafter the decrease flag of the change rate is set to 1.

Alternatively, when the new data change rate is small (slope K)_set2≤k_m+1≤K_set1) When the height is judged to have no ascending or descending trend, the array D is normally counted₁～D_m+1Up to n data samples (if m + 1)>n, then according to the queue mode, D₁～D_nUpdate of data of to D₂～D_m+1(ii) a ) UP is 0 and DOWN is 0 in order to eliminate jitter introduced by the circuit.

Specifically, the rate of change k between the weighted average of the m +1 th data and the previous m data_m+1Less than a set value K_set1In the case of (1), if the rate of change k between the weighted average of the m +1 th data and the m previous data_m+1Greater than a set value K_set2Then, the data length L is equal to m +1 until L is equal to n.

After the sample number length is calculated, an array with self-adaptive data length can be obtained.

And 3, circularly executing the step 1 and the step 2.

The used times can be 2 times, 3 times or more calculation slope results, and the adjustment needs to be made by combining specific parameters of the system.

Since the processing and functions of the automobile of this embodiment are basically corresponding to the embodiment, principle and example of the device shown in fig. 1, the description of this embodiment is not given in detail, and reference may be made to the related description in the foregoing embodiment, which is not described herein again.

Through a large number of tests, the technical scheme of the invention is adopted, and the circuit based on the voltage measurement charging constant can quickly acquire different charging and discharging time of different inductance values and capture the small variation of the inductance values; the method combines the change condition of the height of the electric control air suspension, adopts a queue type weighted average method with self-adaptive data length to filter the collected data, achieves the rapidity of collecting inductance data, and can also achieve the effect of effectively improving the stability of the data.

According to the embodiment of the invention, a method for detecting the height of the automobile body corresponding to the automobile is also provided, and a flow chart of the embodiment of the method is shown in fig. 7. The method for detecting the height of the automobile body can comprise the following steps: step S110 to step S140.

In step S110, sampling, by a sampling unit, the time of each charging and discharging of the inductor in the height sensor of the automobile according to a set sampling period, to obtain charging and discharging time as sample data.

Specifically, the signal acquisition module is composed of an acquisition module (such as a main IC chip) and a peripheral circuit thereof; a comparator module comprising a comparator, a RL circuit comprising a resistor and an inductorWherein the voltage U of the power supply₁And a comparison voltage U used as a reference power supply₂Voltage of power supply U₁Voltage U higher than reference power supply₂。

In step S110, a specific process of sampling the time of each charge and discharge of the inductor in the height sensor of the automobile through the sampling unit includes: under the action of excitation of the power supply, the inductor and the resistor in the inductive height sensor are charged and discharged, the comparison module compares the voltage at two ends of the inductor with the voltage provided by the reference power supply and outputs a comparison result, and the acquisition module acquires the time difference from the time of excitation of the power supply to the time of comparison result output by the comparison module and takes the time difference as the charging and discharging time of the inductor in the inductive height sensor of the automobile.

At step S120, determining, by the control unit, a maximum data length, denoted as n, of a data group formed by the sampling data in a set sampling period; and determining an average value of the first m sampled data within the data length; wherein n and m are positive integers, and m is less than or equal to n.

In some embodiments, the specific process of determining the maximum data length of the data group formed by the sample data in step S120 by the control unit includes: the control unit is specifically further configured to determine a maximum data length of a data group formed by the sample data according to the following formula:

In some embodiments, the specific process of determining the average value of the first m sample data by the control unit in step S120 includes: the control unit is specifically configured to assign a set weight to each of the first m pieces of sample data, and calculate a weighted average of the first m pieces of sample data.

At step S130, by the control unit, further determining a change rate between the m +1 th sampling data and the average value, that is, a difference value between the m +1 th sampling data and the average value as the change rate, and determining an effective data length of a data group formed by the sampling data according to the change rate; wherein, the change rate is a ratio of a difference value between the m +1 th sample data and the average value to a set sampling period.

In some embodiments, the specific process of determining the effective data length of the data group formed by the sample data according to the change rate in step S130 by the control unit may be referred to the following exemplary description.

With reference to the flowchart of fig. 8, which shows an embodiment of the method according to the present invention, that determines the effective data length of the data group formed by the sample data according to the deviation amount, a specific process of determining the effective data length of the data group formed by the sample data according to the deviation amount in step S130 may include: step S210 to step S240.

Step S210, determining, by the control unit, whether the change rate is greater than or equal to a first set value.

Step S220, via the control unit, if the change rate is greater than or equal to the first set value (e.g. K)_set1) If the rising flag of the change rate is 1, determining that the effective data length of a data group formed by the sampling data is m-1, and still setting the rising flag of the change rate to 1; and under the condition that the ascending flag of the change rate is not 1, determining that the effective data length of the data group formed by the sampling data is m +1 until the effective data length of the data group formed by the sampling data is n, and still setting the ascending flag of the change rate to be 1.

Specifically, when the new data positive change rate is large (slope k)_m+1≥K_set1) When the UP flag UP is 1; when the new data positive change rate is judged to be large continuously twice, namely the height is judged to have the rising trend, the length of the calculation array is shortened, and the rising change of the height can be responded quickly. Such as the rate of change k between the weighted average of the m +1 th data and the previous m data_m+1Is greater than or equal to a set value K_set1When the rising flag of the change rate is 1, the data length is shortened from L ═ m to L ═ m +1-2, and then the rising flag of the change rate is still set to 1; if the rising flag of the change rate is not 1, the data length L is made m +1, and the data length L is set to be equal to m +1Until L ═ n, the rising flag of the rate of change is made 1 thereafter.

Step S230, via the control unit, if the change rate is smaller than the first set value, the change rate is smaller than or equal to a second set value (e.g. K)_set2) If the drop flag of the change rate is 1, determining that the effective data length of the data group formed by the sampling data is m-1 until the effective data length of the data group formed by the sampling data is 1, and still setting the drop of the change rate to 1; if the drop flag of the change rate is not 1, determining that the effective data length of the data group formed by the sampling data is m +1 until the effective data length of the data group formed by the sampling data is n, and still setting the drop flag of the change rate to 1.

Step S240, by the control unit, if the change rate is smaller than the first set value, determining that the effective data length of the data group formed by the sample data is m +1 until the effective data length of the data group formed by the sample data is n if the change rate is larger than a second set value.

In some embodiments, the specific process of determining the effective data length of the data group formed by the sample data according to the change rate in step S130 by the control unit further includes any one of the following cyclic control processes:

the first cycle control process: the control unit is specifically configured to, when the effective data length of the data group formed by the sample data is m-1, remove the sample data of the 1 st time and the sample data of the 2 nd time from the data group formed by the sample data, then continue to use the difference between the m +2 th sample data and the average value of the sample data of the 3 rd time to the m +1 th time as the change rate, and continue to determine the effective data length of the data group formed by the sample data according to the change rate.

In step S140, the body height of the automobile is determined by the control unit according to the effective data length of the data set formed by the sampling data and the data set of the sampling data corresponding to the effective data length.

In some embodiments, in step S140, a specific process of determining the body height of the automobile according to the data set of the sampling data corresponding to the effective data length may be performed by the control unit, and refer to the following exemplary description.

The following further describes a specific process of determining the body height of the automobile in step S140, with reference to a schematic flow chart of an embodiment of determining the body height of the automobile in the method of the present invention shown in fig. 9, and the specific process may include: step S310 and step S320.

Step S310, determining an average value of the data group of the sampling data corresponding to the effective data length.

Step S320, determining the inductance value of the inductive height sensor according to the average value of the data group of the sampling data corresponding to the effective data length, and determining the height of the automobile body according to the inductance value of the inductive height sensor and the length of the connecting rod of the inductive height sensor of the automobile.

Since the processing and functions implemented by the method of this embodiment substantially correspond to the embodiments, principles and examples of the automobile, reference may be made to the related descriptions in the foregoing embodiments without being detailed in the description of this embodiment, which is not described herein.

Through a large number of tests, the technical scheme of the embodiment is adopted, the principle of inductance charging and discharging is adopted, the calculation of a software data filtering algorithm is combined, the inductance can be rapidly and accurately measured by adopting the measurement of a voltage charging constant according to the principle of inductance charging and discharging of a circuit, and the detection precision of the inductance type height sensor for measuring the height of the automobile body of the automobile can be improved.

In summary, it is readily understood by those skilled in the art that the advantageous modes described above can be freely combined and superimposed without conflict.

The above description is only an example of the present invention, and is not intended to limit the present invention, and it is obvious to those skilled in the art that various modifications and variations can be made in the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A body height detecting device for an automobile, comprising: a sampling unit and a control unit; wherein,

the sampling unit is configured to sample the time of each charging and discharging of an inductor in the height sensor of the automobile according to a set sampling period to obtain charging and discharging time as sampling data;

the control unit is configured to determine the maximum data length of a data group formed by the sampling data within a set sampling period, and the maximum data length is recorded as n; and determining an average value of the first m sample data within the maximum data length; wherein n and m are positive integers, and m is less than or equal to n;

the control unit, regard the difference between the (m + 1) th sampled data and the said mean value as the rate of change, and confirm the effective data length of the data array that the said sampled data forms according to the said rate of change, including: determining whether the rate of change is greater than or equal to a first set value; if the change rate is greater than or equal to the first set value, determining that the effective data length of a data group formed by the sampling data is m-1 under the condition that the rising flag of the change rate is 1, and still setting the rising flag of the change rate to be 1; under the condition that the ascending flag of the change rate is not 1, determining that the effective data length of the data group formed by the sampling data is m +1 until the effective data length of the data group formed by the sampling data is n, and still setting the ascending flag of the change rate to be 1; if the change rate is smaller than the first set value, under the condition that the change rate is smaller than or equal to a second set value, if a drop flag of the change rate is 1, determining that the effective data length of the data group formed by the sampling data is m-1 until the effective data length of the data group formed by the sampling data is 1, and still setting the drop of the change rate to 1; if the drop flag of the change rate is not 1, determining that the effective data length of the data group formed by the sampling data is m +1 until the effective data length of the data group formed by the sampling data is n, and still setting the drop flag of the change rate to 1; if the change rate is smaller than the first set value, determining that the effective data length of the data group formed by the sampling data is m +1 under the condition that the change rate is larger than a second set value until the effective data length of the data group formed by the sampling data is n;

and determining the height of the automobile body according to the data group of the sampling data corresponding to the effective data length.

2. The vehicle body height detecting apparatus of claim 1, wherein the sampling unit includes: the device comprises a power supply, a reference power supply, a comparison module and an acquisition module;

wherein, the sampling unit samples the time of inductance charging and discharging in the height sensor of car every time, includes:

under the action of excitation of the power supply, the inductor and the resistor in the height sensor are charged and discharged, the comparison module compares the voltage at two ends of the inductor with the voltage provided by the reference power supply and outputs a comparison result, and the acquisition module acquires the time difference from the excitation time of the power supply to the comparison result output time of the comparison module and takes the time difference as the charging and discharging time of the inductor in the height sensor of the automobile.

3. The vehicle body height detecting apparatus according to claim 1 or 2, wherein the control unit determines a maximum data length of the data group constituted by the sample data, including:

determining the maximum data length of a data group formed by the sampling data according to the following formula:

4. The vehicle body height detection device of an automobile according to claim 1 or 2, wherein the control unit determines an average value of the first m sampled data, including:

and (4) assigning a set weight to each data in the first m sampling data, and calculating a weighted average value of the first m sampling data.

5. The apparatus according to claim 1, wherein the control unit determines an effective data length of a data group formed by the sample data based on the change rate, and further comprises:

under the condition that the effective data length of a data group formed by the sampling data is m-1, eliminating the sampling data of the 1 st time and the sampling data of the 2 nd time from the data group formed by the sampling data, then continuously taking the difference value between the m +2 th sampling data and the average value of the sampling data of the 3 rd time to the m +1 th time as a change rate, and continuously determining the effective data length of the data group formed by the sampling data according to the change rate;

under the condition that the effective data length of the data group formed by the sampling data is m +1, adding the sampling data for m +1 times in the data group formed by the sampling data, then determining the average value of the first m +1 sampling data, continuously taking the difference value between the m +2 sampling data and the average value of the first m +1 sampling data as the change rate, and continuously determining the effective data length of the data group formed by the sampling data according to the change rate;

under the condition that the effective data length of a data group formed by the sampling data is n, removing the 1 st sampling data from the data group formed by the sampling data, adding the m +1 th sampling data, then determining the average value of the 2 nd sampling data to the m +1 th sampling data, continuously taking the difference value between the m +2 th sampling data and the average value of the 2 nd sampling data to the m +1 th sampling data as a change rate, and continuously determining the effective data length of the data group formed by the sampling data according to the change rate.

6. The apparatus according to claim 1 or 2, wherein the control unit determines the body height of the vehicle based on the data group of the sampled data corresponding to the effective data length, and includes:

determining an average value of the data group of the sampling data corresponding to the effective data length;

and determining the inductance value of the height sensor according to the average value of the data group of the sampling data corresponding to the effective data length, and determining the height of the automobile body of the automobile according to the inductance value of the height sensor and the length of the connecting rod of the height sensor of the automobile.

7. An automobile, comprising: the vehicle body height detection device of the automobile according to any one of claims 1 to 6.

8. A method for detecting the height of a vehicle body of an automobile, comprising:

sampling the time of each charge and discharge of an inductor in the height sensor of the automobile according to a set sampling period through a sampling unit to obtain the charge and discharge time as sampling data;

determining the maximum data length of a data group formed by the sampling data within a set sampling period through a control unit, and recording the maximum data length as n; and determining an average value of the first m sample data within the maximum data length; wherein n and m are positive integers, and m is less than or equal to n; by the control unit, taking the difference value between the (m + 1) th sampling data and the average value as a change rate, and determining the effective data length of a data group formed by the sampling data according to the change rate, wherein the method comprises the following steps: determining whether the rate of change is greater than or equal to a first set value; if the change rate is greater than or equal to the first set value, determining that the effective data length of a data group formed by the sampling data is m-1 under the condition that the rising flag of the change rate is 1, and still setting the rising flag of the change rate to be 1; under the condition that the ascending flag of the change rate is not 1, determining that the effective data length of the data group formed by the sampling data is m +1 until the effective data length of the data group formed by the sampling data is n, and still setting the ascending flag of the change rate to be 1; if the change rate is smaller than the first set value, under the condition that the change rate is smaller than or equal to a second set value, if a drop flag of the change rate is 1, determining that the effective data length of the data group formed by the sampling data is m-1 until the effective data length of the data group formed by the sampling data is 1, and still setting the drop of the change rate to 1; if the drop flag of the change rate is not 1, determining that the effective data length of the data group formed by the sampling data is m +1 until the effective data length of the data group formed by the sampling data is n, and still setting the drop flag of the change rate to 1; if the change rate is smaller than the first set value, determining that the effective data length of the data group formed by the sampling data is m +1 under the condition that the change rate is larger than a second set value until the effective data length of the data group formed by the sampling data is n;

9. The method for detecting the body height of an automobile according to claim 8, wherein the sampling unit includes: the device comprises a power supply, a reference power supply, a comparison module and an acquisition module;

wherein, through the sampling unit, to the inductance is the time of charging and discharging at every turn in the height sensor of car samples, includes:

10. The method for detecting the body height of the automobile according to claim 8 or 9, wherein determining, by the control unit, the maximum data length of the data group constituted by the sample data includes:

11. The vehicle body height detection method of an automobile according to claim 8 or 9, wherein determining, by the control unit, an average value of the first m sampled data includes:

12. The method for detecting the body height of an automobile according to claim 8, wherein determining, by the control unit, the effective data length of the data group constituted by the sample data based on the change rate further includes:

13. The method for detecting the body height of the automobile according to claim 8 or 9, wherein determining the body height of the automobile by a control unit based on the data group of the sampled data corresponding to the effective data length includes: