CN108196616B - Time synchronization method for detecting data of variable-diameter inertial navigation subsystem in pipeline - Google Patents
Time synchronization method for detecting data of variable-diameter inertial navigation subsystem in pipeline Download PDFInfo
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Abstract
本发明公开了一种基于里程数据时间的PIG变径、惯导子系统输出数据的同步操作流程。该流程首先将变径和惯导输出数据矩阵中的里程数据列图形化,将采样点数作为横轴;然后使用启动点搜索方法分别在两个图中标记里程数据从静止到运动一瞬间的采样点数;进而求出在各自系统时钟中里程数据从静止到运动一瞬间对应的时间;最后,求出两个时钟的差值,把变径和惯导子系统的时钟修正成同一时间,实现数据的同步。采用本发明的同步方法,相对于使用全部里程数据作为同步基准的方法,可以有效解决PIG运动过程中里程计失效或者后期里程数据修正造成的同步失败问题,只要保证发球筒阶段里程数据的完整,可以对两个子系统全部输出数据进行同步操作。
The invention discloses a synchronous operation flow of PIG variable diameter and inertial navigation subsystem output data based on mileage data time. The process first graphs the odometer data column in the variable diameter and inertial navigation output data matrix, and takes the number of sampling points as the horizontal axis; then uses the starting point search method to mark the sampling of the odometer data from stationary to the moment of movement in the two graphs respectively Then, the time corresponding to the mileage data in the respective system clocks from stationary to the moment of movement is obtained; finally, the difference between the two clocks is obtained, and the clocks of the variable diameter and the inertial navigation subsystem are corrected to the same time to realize the data synchronization. The synchronization method of the present invention can effectively solve the synchronization failure problem caused by the failure of the odometer during the PIG movement or the correction of the mileage data in the later stage, as long as the integrity of the mileage data in the stage of the ball is guaranteed, All output data of the two subsystems can be synchronized.
Description
技术领域technical field
本发明涉及管道内检测装置的内部子系统输出数据的同步方法,具体地说是涉及管道内检测装置中变径和惯导两个子系统,各种管道管径的变径/惯导组合内检测系统都可以使用该同步方法。The invention relates to a method for synchronizing output data from an internal subsystem of a detection device in a pipeline, in particular to two subsystems of variable diameter and inertial navigation in a pipeline detection device, and the combined internal detection of variable diameter and inertial navigation of various pipeline diameters The synchronization method can be used by any system.
背景技术Background technique
1.管道内检测1. In-pipe inspection
管道内检测装置(PIG)在管道内运动过程中,可以对管道缺陷或变形情况进行测量。PIG通常根据当前的任务需要,可以搭载多个检测子系统。由于需要根据不同任务灵活组合各检测子系统,各子系统通常有独立的数据采集和存储能力。由于变径装置占用PIG空间相对较小,因此经常和惯导装置安装在一个PIG的腔体中,在空间上看成一体,可以共享一个里程数据。In-pipe inspection device (PIG) can measure pipeline defects or deformation during the movement of pipeline. PIG can usually carry multiple detection subsystems according to the current mission needs. Since each detection subsystem needs to be flexibly combined according to different tasks, each subsystem usually has independent data acquisition and storage capabilities. Since the reducing device occupies a relatively small space in the PIG, it is often installed in the cavity of a PIG with the inertial navigation device, which can be regarded as one in space and can share a mileage data.
2.PIG内部子系统之间的同步问题2. Synchronization between internal subsystems of PIG
当多个检测子系统之间需要配合使用时,数据之间的同步关系非常重要。例如,当变径检测和惯导定位检测两个子系统搭载在同一PIG平台上,同时进行在线检测,理论上下载的数据应该是高度同步的,即当检测工作结束,依照检测得到的数据,惯导定位和变径检测的对象必须在时间和空间上保持同一个尺度。具体来说,如果变径检测器检出某个管壁缺陷,同一时间,惯导定位装置就应该给出该缺陷对应的地理坐标。When multiple detection subsystems need to be used together, the synchronization relationship between data is very important. For example, when the two subsystems of variable diameter detection and inertial navigation positioning detection are mounted on the same PIG platform and perform online detection at the same time, theoretically the downloaded data should be highly synchronized, that is, when the detection work is completed, according to the detected data, the customary The objects of guide positioning and variable diameter detection must maintain the same scale in time and space. Specifically, if the variable diameter detector detects a certain pipe wall defect, the inertial navigation positioning device should give the corresponding geographical coordinates of the defect at the same time.
但是,由于传感器检测原理不同,对应的检测装置的电器结构也不同,采样率、信号格式、系统时钟,甚至输出数据的格式都完全不同。因此,很难确定惯导和变径两个子系统的输出数据在时间上的一一对应关系。However, due to the different detection principles of the sensors, the electrical structures of the corresponding detection devices are also different, and the sampling rate, signal format, system clock, and even the format of the output data are completely different. Therefore, it is difficult to determine the one-to-one correspondence between the output data of the inertial navigation and variable diameter subsystems in time.
这就需要在两个子系统都完成数据输出之后,对两批输出数据进行同步操作。实质是保证两批输出数据在各自的时间轴上使用同一个时间标尺。This requires that the two batches of output data be synchronized after the two subsystems complete the data output. The essence is to ensure that the two batches of output data use the same time scale on their respective time axes.
3.现有同步方法的局限3. Limitations of Existing Synchronization Methods
之前解决该问题的方法是直接使用里程数据作为同步基准的方法。把同一路里程计信号分别引入不同的检测子系统,使其作为输出数据矩阵的一列。所谓输出数据矩阵,指每一行数据包括多个数据项(里程是其中之一),被称为一个采样点;采样点所有数据来源于该检测子系统同一时刻的采样;通过引入该子系统采样频率、信号格式等参数,可以计算出该行采样点在该子系统时钟下的采样时间。由于每个采样点都包含一个里程数据项,可以在输出数据时,把里程数据作为坐标的横轴。当不同的检测子系统使用共同的里程数据作为坐标系的横轴,就实现了不同子系统输出数据的同步。The previous solution to this problem was to directly use the mileage data as a synchronization reference. The same odometer signal is introduced into different detection subsystems as a column of the output data matrix. The so-called output data matrix means that each row of data includes multiple data items (mileage is one of them), which is called a sampling point; all data at the sampling point comes from the sampling of the detection subsystem at the same time; by introducing the sampling of the subsystem Parameters such as frequency, signal format, etc., can calculate the sampling time of the sampling point of this line under the clock of this subsystem. Since each sampling point contains a mileage data item, the mileage data can be used as the horizontal axis of the coordinates when outputting data. When different detection subsystems use the common mileage data as the horizontal axis of the coordinate system, the synchronization of the output data of different subsystems is realized.
上述直接使用里程数据作为同步基准信号的缺点如下:The disadvantages of the above-mentioned direct use of mileage data as the synchronization reference signal are as follows:
1)容易失效。里程计运行在PIG的保护壳体外部,相对于其他检测子系统,数据失效的概率更高。在油气管道内部,工作环境非常恶劣,里程计的机械结构故障率很高。即便里程计在一百小时左右的恶劣环境下保持机械结构没有变形和损坏,但高粘度原油、高度腐蚀性的天然气、管道内壁缺陷等,都可能造成里程计打滑、卡死、电气部件失效等严重问题。一旦里程数据部分或全部失效,则所有的同步操作无法进行。1) It is easy to fail. The odometer runs outside the protective housing of the PIG, and has a higher probability of data failure than other detection subsystems. Inside the oil and gas pipeline, the working environment is very harsh, and the mechanical structure of the odometer has a high failure rate. Even if the odometer maintains its mechanical structure without deformation and damage in a harsh environment of about 100 hours, high-viscosity crude oil, highly corrosive natural gas, and defects on the inner wall of the pipeline may cause the odometer to slip, get stuck, and fail to electrical components, etc. Serious Problem. Once the mileage data is partially or completely invalidated, all synchronization operations cannot be performed.
2)里程修正导致相关的同步数据也要重新进行修正。测量之后,里程数据的精度也有修正的必要,例如对里程计打滑的补偿计算等。但里程数据作为同步基准数据,一旦进行修正,其相关的所有子系统的检测数据也要分别进行同步修正。也就是说,在两个子系统的同步操作之前,为了保证两个子系统内部的输出数据和当前的里程输出数据“绑定”在一起,必须在子系统输出数据内部先进行“同步”操作,而且这种子系统内部的“同步”操作还可能进行多次。这明显提高了系统数据处理的复杂性,降低了系统可靠性。2) The mileage correction causes the related synchronization data to be corrected again. After the measurement, the accuracy of the odometer data also needs to be corrected, such as the compensation calculation for the slippage of the odometer. However, the mileage data is used as the synchronization reference data. Once the correction is performed, the detection data of all the related subsystems should also be corrected separately. That is to say, before the synchronization operation of the two subsystems, in order to ensure that the output data inside the two subsystems and the current mileage output data are "bound" together, the "synchronization" operation must be performed within the output data of the subsystems, and This "synchronization" operation within the subsystem may also be performed multiple times. This obviously increases the complexity of system data processing and reduces system reliability.
发明内容SUMMARY OF THE INVENTION
发明目的Purpose of invention
本发明的目的是解决变径和惯导两个子系统的里程同步方法的上述问题,使得里程数据在离开发球筒之后的运动部分数据失效后,或者里程数据进行局部或全局的修正后,仍然可以计算得到启动点时间作为同步基准,保证相对较高的同步精度。The purpose of the present invention is to solve the above problem of the mileage synchronization method of the variable diameter and inertial navigation subsystems, so that the mileage data can still be used after the data of the moving part after leaving the ball cylinder is invalid, or after the mileage data is corrected locally or globally. The start point time is calculated and used as the synchronization reference to ensure relatively high synchronization accuracy.
技术方案Technical solutions
管道内检测变径惯导子系统数据的时间同步方法,PIG系统的一个里程计信号同时被引入安装在一个舱体的变径和惯导两个子系统;在发球筒阶段,里程数据完整;在上电运行过程中,两个子系统各自的系统时钟处于相同的精度水平;其特征在于:方法步骤如下:The time synchronization method for detecting the data of the variable diameter inertial navigation subsystem in the pipeline, an odometer signal of the PIG system is simultaneously introduced into the two subsystems of the variable diameter and inertial navigation installed in a cabin; in the stage of the ball, the odometer data is complete; During the power-on operation, the respective system clocks of the two subsystems are at the same precision level; it is characterized in that the method steps are as follows:
步骤一,分别将变径和惯导输出数据矩阵中的里程计原始数据图形化,定义为惯导子系统里程计原始数据图和变径子系统里程计原始数据图;Step 1: The odometer raw data in the variable diameter and inertial navigation output data matrix are graphed respectively, and are defined as the odometer raw data map of the inertial navigation subsystem and the odometer raw data map of the variable diameter subsystem;
惯导子系统和变径子系统输出数据的格式类似,都是组织成二维表格形式,每一行数据包括多个数据项,里程计原始信号也是其中之一,每一行数据被称为一个采样点;从上电、自检、启动后正常采集数据开始,采样点按照时间排列的正整数序列称为采样点数,定义为m,m为正整数;The format of the output data of the inertial navigation subsystem and the variable diameter subsystem is similar. They are organized into a two-dimensional table form. Each row of data includes multiple data items, and the original odometer signal is also one of them. Each row of data is called a sampling point. ; Starting from the normal collection of data after power-on, self-test, and startup, the positive integer sequence of sampling points arranged according to time is called the number of sampling points, which is defined as m, where m is a positive integer;
将上电后获得的第一个采样点放置在坐标轴原点上,即0点,将后续的采样点数m对映横轴的正整数,即1到N个采样点数;每个采样点数对应的里程计原始信号值作为纵轴;The first sampling point obtained after power-on is placed on the origin of the coordinate axis, that is,
步骤二,定义PIG在发球筒中从静止状态转换到运动状态的瞬间为启动点,变径和惯导两个子系统的启动点的物理时间是一样的;对两个子系统的里程计原始信号采用启动点搜索算法,分别在惯导子系统里程计原始数据图和变径子系统里程计原始数据图中标记启动点的采样点数,定义为m1和m2;
所述启动点搜索算法如下:The starting point search algorithm is as follows:
1)确定搜索启动点算法的精度目标search_time,该精度必须和整个同步算法的精度目标相匹配,即搜索算法的精度目标比整个同步算法的精度目标高一个数量级,即搜索算法的误差时间search_time是同步算法误差时间goal_time的N分之一;1) Determine the accuracy target search_time of the search start point algorithm, which must match the accuracy target of the entire synchronization algorithm, that is, the accuracy target of the search algorithm is an order of magnitude higher than the accuracy target of the entire synchronization algorithm, that is, the error time search_time of the search algorithm is 1/N of the synchronization algorithm error time goal_time;
2)确定搜索步长step:定义某个子系统的采样频率(一秒钟的采样点个数)为sample_times,则搜索的步长为搜索启动点算法的精度目标乘以采样频率2) Determine the search step size step: Define the sampling frequency of a subsystem (the number of sampling points in one second) as sample_times, then the search step size is the accuracy target of the search start point algorithm multiplied by the sampling frequency
step=search_time×sample_timesstep=search_time×sample_times
搜索过程中,当第i次搜索的采样点数是mi,则第i+1次搜索的采样点数mi+1有During the search process, when the number of sampling points in the i-th search is m i , the number of sampling points in the i+1-th search m i+1 has
mi+1=mi+stepm i+1 =m i +step
3)定义搜索空间Ss:3) Define the search space S s :
Ss区间是采样点数组成的集合,是里程原始数据横坐标上的一段连续区间,由搜索的起点m_start和终点m_end定义;S s interval is a collection of sampling points, which is a continuous interval on the abscissa of the original mileage data, defined by the starting point m_start and the ending point m_end of the search;
定义Ss的原则是:保证搜索的目标,即启动点,在m_start和m_end之间;The principle of defining S s is to ensure that the search target, that is, the starting point, is between m_start and m_end;
设定Ss的方法如下:观察里程原始数据的图形,启动点必然处于平直区域向振荡区域的过渡区域,把这个过渡区域的左边界设定为m_start;The method of setting S s is as follows: observe the graph of the original mileage data, the starting point must be in the transition area from the flat area to the oscillating area, and set the left boundary of this transition area as m_start;
m_start是开始搜索的采样点数,m_end是结束搜索的采样点数,进行后续的搜索计算,此时能够确定最大搜索次数Ns为m_start is the number of sampling points to start the search, and m_end is the number of sampling points to end the search. For subsequent search calculations, it can be determined that the maximum number of searches N s is
Ns=(m_end-m_start)/stepN s =(m_end-m_start)/step
令i为当前搜索的次数,定义搜索空间Let i be the number of current searches to define the search space
Ss={mi∣m_start≤mi≤m_end,i=1,2,…,Ns}S s ={m i ∣m_start≤m i ≤m_end,i=1,2,...,N s }
其中mi为第i次搜索的采样点数;where m i is the number of sampling points in the ith search;
4)确定发球筒内PIG的静置区间S;静置区间,即在子系统里程计原始信号图中标记的,PIG处于静置状态,没有微小移动的采样点数的集合区间,定义静置区间边界采样点数分别为ms0和ms1,则能够定义4) Determine the static interval S of the PIG in the serving cylinder; the static interval, that is, marked in the original signal diagram of the subsystem odometer, the PIG is in a static state, and the collection interval of the sampling points without slight movement, define the static interval The number of boundary sampling points is m s0 and m s1 respectively, then it can be defined
S={(m,SV)∣ms0≤m≤ms1}S={(m,S V )∣m s0 ≤m≤m s1 }
其中m为静置区间的采样点数,SV为m所对应的里程计原始信号;where m is the number of sampling points in the static interval, and S V is the original odometer signal corresponding to m;
设定S的方法如下:在里程原始数据图上观察,从原点开始,图像会迅速趋于稳定,并进入一个平直的区域,该区域从横坐标看,将持续很多个采样点数,在这个平直区域中,图像只有高频的噪声信号,而不会出现纵坐标的较大起伏,把这个区域的左边界标记为采样点数ms0,右边界标记为采样点数ms1;The method of setting S is as follows: Observe on the original mileage data map, starting from the origin, the image will quickly become stable and enter a flat area, which will last for many sampling points from the abscissa. In the flat area, the image only has high-frequency noise signals, and there will be no large fluctuations in the ordinate. The left boundary of this area is marked as the number of sampling points m s0 , and the right boundary is marked as the number of sampling points m s1 ;
在保证PIG处于静止状态的前提下,S区间应尽可能大,从统计意义上能够更精确的求出静置时SV的观测值,即静置区间S内所有SV的均值,定义为E(SV);On the premise of ensuring that the PIG is in a static state, the S interval should be as large as possible. In a statistical sense, the observed value of S V at rest can be more accurately obtained, that is, the mean value of all S V in the static interval S, which is defined as E(S V );
5)设置搜索中使用的参数:5) Set the parameters used in the search:
定义第i次搜索的目标采样点数为mi,mi∈Ss;Define the number of target sampling points for the i-th search as m i , where m i ∈ S s ;
定义第i次搜索时需要用到的两个集合:左集合(Sl)和右集合(Sr),定义左集合包含的采样点数为ml,定义右集合包含的采样点数为mr;两个集合Sl和Sr,他们分别是以当前搜索的采样点数mi为中心,位于mi左、右两侧的两个采样点集合,这两个集合内元素的个数设为1秒内的全部采样点的个数,即sample_times,有Define the two sets that need to be used in the ith search: the left set (S l ) and the right set (S r ), define the number of sampling points contained in the left set as m l , and define the number of sampling points contained in the right set as m r ; Two sets S l and S r , they are respectively the two sampling point sets located on the left and right sides of m i centered on the number of sampling points currently searched for m i , and the number of elements in these two sets is set to 1 The number of all sampling points in seconds, that is, sample_times, there are
Sl={(ml,SV)∣mi-sample_times≤ml≤mi,mi∈Ss}S l ={(m l ,S V )∣m i -sample_times≤m l ≤m i ,m i ∈S s }
Sr={(mr,SV)∣mi≤mr≤mi+sample_times,mi∈Ss}S r ={(m r ,S V )∣m i ≤m r ≤m i +sample_times,m i ∈S s }
两个集合全部SV的均值分别定义为El(SV)和Er(SV),即El(SV)为Sl内的全部SV的观测值,Er(SV)为Sr内的全部SV的观测值,当mi是启动点,则El(SV)必然趋近于E(SV),而Er(SV)必然大于E(SV);当mi不是启动点,则El(SV)和Er(SV)必然同样趋近于E(SV)或者同样大于E(SV); The mean values of all SVs of the two sets are defined as El (SV) and Er (SV) respectively, that is, El ( SV ) is the observed value of all SVs in Sl , and Er ( SV ) is the observed value of all S V in S r , when mi is the starting point, then El (S V ) must approach E(S V ), and E r (S V ) must be greater than E(S V ) ; When mi is not the starting point, then E l (S V ) and Er (S V ) must also approach E(S V ) or be greater than E(S V ) ;
定义本次搜索用于判定的两个门槛值εl和εr,初始设定的原则是εl>0,且尽可能小,而εr比εl大一个数量级,即εr比εl大M倍,M取2到10的整数;如果初始设定搜索得到的启动点多于1个,则减小εl并增加εr,重新搜索;Define the two threshold values ε l and ε r used for the determination of this search. The principle of initial setting is that ε l > 0, and it is as small as possible, and ε r is an order of magnitude larger than ε l , that is, ε r is larger than ε l M times larger, M is an integer from 2 to 10; if there are more than 1 starting point obtained by the initial search, decrease ε l and increase ε r , and search again;
6)在Ss范围内,从m_start开始,到m_end结束,搜索启动点,共进行Ns次搜索计算;对第i次搜索,i=1,2,…,Ns,当有6) In the range of S s , starting from m_start and ending at m_end, searching for the starting point, a total of N s search calculations are performed; for the i-th search, i=1,2,...,N s , when there are
∣El(SV)-E(SV)∣<εl而且Er(SV)-E(SV)>εr ∣E l (S V )-E(S V )∣<ε l and E r (S V )-E(S V )>ε r
成立,则接受mi为启动点;当If established, accept m i as the starting point; when
∣El(mi)-E(SV)∣≥εl或者Er(mi)-E(SV)≤εr ∣E l (m i )-E(S V )∣≥ε l or E r (m i )-E(S V )≤ε r
成立,则需要对mi+1采样点数继续进行第i+1次搜索,其中mi+1=mi+step;If it is established, it is necessary to continue the i+1th search for the number of m i+1 sampling points, where m i+1 =m i +step;
7)如果上面的搜索完成,得到的启动点只有一个,则该子系统的启动点搜索算法结束,如果在整个Ss范围内,按照当前的εl和εr搜索,可以得到多个启动点,则需要调整εl和εr,重新进行搜索,直至剩下一个为止;调整的方法是,减小εl或者增加εr;该εl和εr必须在两个子系统的里程计原始数据中同时使用,分别得到启动点m1和m2;7) If the above search is completed and only one starting point is obtained, the starting point search algorithm of the subsystem ends. If the search is performed according to the current ε l and ε r in the entire S s range, multiple starting points can be obtained. , then you need to adjust ε l and ε r , and search again until there is one left; the adjustment method is to decrease ε l or increase ε r ; the ε l and ε r must be in the original odometer data of the two subsystems are used at the same time, and the starting points m1 and m2 are obtained respectively;
步骤三,根据变径和惯导两个子系统各自的采样频率sample_times,分别在变径和惯导两个子系统里程计原始信号图中求出每个采样点数m在各自系统时钟下的对应时间t,包括m1和m2在各自系统时钟中对应的时间t1和t2,Step 3: According to the respective sampling frequencies sample_times of the variable diameter and inertial navigation subsystems, obtain the corresponding time t of each sampling point m under the respective system clocks in the odometer original signal diagrams of the variable diameter and inertial navigation subsystems respectively. , including the corresponding times t1 and t2 of m1 and m2 in their respective system clocks,
t=m/sample_timest=m/sample_times
把原来采样点数m的横轴转化为当前子系统时钟t的横轴;Convert the horizontal axis of the original number of sampling points m to the horizontal axis of the current subsystem clock t;
步骤四,求出t1和t2的差值Δt:Δt=t2-t1,Δt作为两个子系统时钟的差值;Step 4: Calculate the difference Δt between t1 and t2: Δt=t2-t1, Δt is used as the difference between the two subsystem clocks;
步骤五,利用Δt,把两个子系统的时钟修正成同一时间,实现变径、惯导两个子系统数据的同步;Step 5: Use Δt to correct the clocks of the two subsystems to the same time to realize the synchronization of the data of the variable diameter and inertial navigation subsystems;
当需要把变径子系统时钟作为后续处理的标准时间时,则惯导子系统所有采样点的对应时间需要减Δt;当需要惯导子系统时间为标准时间时,则变径子系统的所有时间参数需要加Δt。When the variable diameter subsystem clock needs to be used as the standard time for subsequent processing, the corresponding time of all sampling points of the inertial navigation subsystem needs to be reduced by Δt; when the inertial navigation subsystem time is required to be the standard time, all the time parameters of the variable diameter subsystem Need to add Δt.
优点及效果Advantages and Effects
与现有技术相比,本发明的有益效果是:Compared with the prior art, the beneficial effects of the present invention are:
首先,显著的解决了里程计失效则同步操作无法进行的问题。里程计主体部分是机械结构,故障几乎都发生在离开发球筒之后的运动过程中,发球筒阶段通常不会出问题。而本发明只要求发球筒阶段数据完整,即可以找到步骤二的m1和m2,整个算法后续不受影响。实质上把里程计失效对后续同步操作的影响消除了。First of all, the problem that the synchronization operation cannot be performed due to the failure of the odometer is significantly solved. The main part of the odometer is a mechanical structure, and the failure almost always occurs during the movement after leaving the ball barrel, and there is usually no problem in the ball barrel stage. However, the present invention only requires that the data at the stage of the ball is complete, that is, m1 and m2 in
其次,完全解决了里程计数据修正导致的之前同步操作结果失效的问题。里程数据的修正主要针对PIG运行中出现的打滑和数据一致性等问题,不会影响发球筒静置阶段的数据,因此不会影响步骤二的m1和m2的取值,也就不会影响后续的同步操作。Secondly, the problem of the failure of the previous synchronization operation results caused by the correction of the odometer data is completely solved. The correction of the mileage data is mainly aimed at the problems of slippage and data consistency in the operation of the PIG, and will not affect the data in the static stage of the ball cylinder, so it will not affect the values of m1 and m2 in
附图说明Description of drawings
图1为惯导子系统里程计原始数据;Figure 1 is the original data of the odometer of the inertial navigation subsystem;
图2为变径子系统里程计原始数据;Figure 2 is the original data of the variable diameter subsystem odometer;
图3为惯导子系统里程计输出数据;Figure 3 is the odometer output data of the inertial navigation subsystem;
图4为变径子系统里程计输出数据;Figure 4 is the output data of the variable diameter subsystem odometer;
图5为同一时间尺度下变径和惯导输出的里程数据;Figure 5 shows the mileage data of variable diameter and inertial navigation output under the same time scale;
图6为惯导子系统里程计原始数据启动点附近的局部放大。Figure 6 is a partial magnification near the starting point of the odometry raw data of the inertial navigation subsystem.
具体实施方式Detailed ways
下面结合附图对本发明做进一步的说明:The present invention will be further described below in conjunction with the accompanying drawings:
图1为典型惯导检测子系统里程的原始数据,横轴为采样点数,纵轴为包含了大量噪声的里程信号,该信号实质上是一个三角波电平,横轴上的m1为发球筒中惯导子系统启动点的采样点数。Figure 1 is the original data of the typical inertial navigation detection subsystem mileage, the horizontal axis is the number of sampling points, the vertical axis is the mileage signal containing a lot of noise, the signal is essentially a triangular wave level, the m1 on the horizontal axis is the inertia of the ball The number of sample points for the start point of the derivative system.
图2为典型变径检测子系统里程的原始数据,横轴为采样点数,纵轴为包含了大量噪声的里程信号,该信号实质上是一个三角波电平,m2为发球筒中变径子系统启动点的采样点数。Figure 2 is the original data of the typical variable diameter detection subsystem mileage, the horizontal axis is the number of sampling points, the vertical axis is the mileage signal containing a lot of noise, the signal is essentially a triangular wave level, m2 is the starting point of the variable diameter subsystem in the ball cylinder the number of sampling points.
图3为典型惯导子系统的输出数据,横轴为时间,纵轴为里程,单位米。t1为惯导子系统时钟标准下,由m1计算得到的惯导子系统在发球筒中经过启动点的时间。Figure 3 shows the output data of a typical inertial navigation subsystem. The horizontal axis is time, and the vertical axis is mileage, in meters. t1 is the time when the inertial navigation subsystem passes the starting point in the ball barrel calculated by m1 under the clock standard of the inertial navigation subsystem.
图4为典型变径子系统的输出数据,横轴为时间,纵轴为里程,单位米。t2为变径子系统时钟标准下,由m2计算得到的变径子系统在发球筒中经过启动点的时间。Figure 4 shows the output data of a typical variable diameter subsystem. The horizontal axis is time, and the vertical axis is mileage, in meters. t2 is the time that the variable diameter subsystem passes the starting point in the ball cylinder under the standard of the variable diameter subsystem clock, calculated by m2.
图5把典型变径检测子系统和惯导检测子系统输出的里程数据放在一个坐标系内,横轴为时间。t1为惯导子系统时钟标准下,由m1计算得到的惯导子系统在发球筒中经过启动点的时间。t2为变径子系统时钟标准下,由m2计算得到的变径子系统在发球筒中经过启动点的时间;Δt为变径和惯导两个子系统时钟的同步误差。Figure 5 puts the mileage data output by the typical variable diameter detection subsystem and the inertial navigation detection subsystem in a coordinate system, and the horizontal axis is time. t1 is the time when the inertial navigation subsystem passes the starting point in the ball barrel calculated by m1 under the clock standard of the inertial navigation subsystem. t2 is the time when the variable diameter subsystem passes the starting point in the ball cylinder calculated by m2 under the standard of the variable diameter subsystem clock; Δt is the synchronization error of the two subsystem clocks of the variable diameter and inertial navigation.
图6为惯导子系统里程计原始数据启动点附近的局部放大,为启动点附近的信号,此时,由于噪声等因素存在,人工方法不能精确定位m1点,所以需要使用启动点搜索算法。Figure 6 shows the local amplification near the starting point of the odometry raw data of the inertial navigation subsystem, which is the signal near the starting point. At this time, due to the existence of noise and other factors, the artificial method cannot accurately locate the m1 point, so the starting point search algorithm needs to be used.
管道内检测系统(PIG)通常搭载多个检测装置,各装置有独立的数据采集和存储能力。由于发球筒和收球筒的尺寸限制,惯导定位装置(核心是IMU系统)和变径检测装置经常作为两个子系统同时搭载PIG进入管道。当多个检测装置之间需要配合使用时,数据之间的同步关系非常重要。但是,由于变径系统和惯导系统各自传感器检测原理不同,对应的电器结构也不同,采样率、信号格式等也完全不同,很可能造成同一时间的不同类型传感器数据在统一时间轴上的错位,因此必须进行同步操作。本操作主要以计算得到的时间数据作为同步依据,其执行的前提是:PIG系统的里程计信号同时被引入变径和惯导两个子系统;两个子系统各自的系统时间处于相同的精度水平。In-pipe inspection systems (PIGs) are usually equipped with multiple inspection devices, each of which has independent data acquisition and storage capabilities. Due to the size limitation of the ball launcher and the ball receiver, the inertial navigation positioning device (the core of which is the IMU system) and the variable diameter detection device are often used as two subsystems to carry PIG into the pipeline at the same time. When multiple detection devices need to be used together, the synchronization relationship between data is very important. However, due to the different detection principles of the sensors of the variable diameter system and the inertial navigation system, the corresponding electrical structures are also different, and the sampling rate and signal format are also completely different, which may cause the dislocation of different types of sensor data at the same time on the unified time axis. , so a synchronous operation is necessary. This operation mainly uses the calculated time data as the synchronization basis. The premise of its execution is: the odometer signal of the PIG system is simultaneously introduced into the variable diameter and inertial navigation subsystems; the respective system times of the two subsystems are at the same level of accuracy.
管道内检测变径惯导子系统数据的时间同步方法,PIG系统的一个里程计信号同时被引入安装在一个舱体的变径和惯导两个子系统;在发球筒阶段,里程数据完整;在上电运行过程中,两个子系统各自的系统时钟处于相同的精度水平;其特征在于:方法步骤如下:The time synchronization method for detecting the data of the variable diameter inertial navigation subsystem in the pipeline, an odometer signal of the PIG system is simultaneously introduced into the two subsystems of the variable diameter and inertial navigation installed in a cabin; in the stage of the ball, the odometer data is complete; During the power-on operation, the respective system clocks of the two subsystems are at the same precision level; it is characterized in that the method steps are as follows:
步骤一,分别将变径和惯导输出数据矩阵中的里程计原始数据图形化,定义为惯导子系统里程计原始数据图(如图1所示)和变径子系统里程计原始数据图(如图2所示);Step 1: The odometer raw data in the variable diameter and inertial navigation output data matrix are graphed respectively, and defined as the odometer raw data map of the inertial navigation subsystem (as shown in Figure 1) and the variable diameter subsystem odometer raw data map ( as shown in picture 2);
惯导子系统和变径子系统输出数据的格式类似,都是组织成二维表格形式,每一行数据包括多个数据项,里程计原始信号(电压值,单位V,后面公式中定义为SV)也是其中之一,每一行数据被称为一个采样点;从上电、自检、启动后正常采集数据开始,采样点按照时间排列的正整数序列称为采样点数,定义为m,m为正整数;The format of the output data of the inertial navigation subsystem and the variable diameter subsystem is similar, and they are organized into a two-dimensional table form. Each row of data includes multiple data items. The original odometer signal (voltage value, unit V, defined as S V in the following formula ) is also one of them, and each line of data is called a sampling point; starting from the normal collection of data after power-on, self-test, and startup, the positive integer sequence of sampling points arranged in time is called the number of sampling points, which is defined as m, where m is positive integer;
将上电后获得的第一个采样点放置在坐标轴原点上,即0点,将后续的采样点数m对映横轴的正整数,即1到N个采样点数;每个采样点数对应的里程计原始信号值作为纵轴;The first sampling point obtained after power-on is placed on the origin of the coordinate axis, that is,
里程计原始信号实质是三角波,参与后续数据处理时需要按照里程计产品说明书提供的方法转换成单位为米的里程,如图3、图4和图5的纵坐标;The original signal of the odometer is essentially a triangular wave. When participating in the subsequent data processing, it needs to be converted into the mileage in meters according to the method provided in the odometer product manual, as shown in the ordinates in Figure 3, Figure 4 and Figure 5;
步骤二,定义PIG在发球筒中从静止状态转换到运动状态的瞬间为启动点,变径和惯导两个子系统的启动点的物理时间是一样的。对两个子系统的里程计原始信号采用启动点搜索算法,分别在惯导子系统里程计原始数据图和变径子系统里程计原始数据图中标记启动点的采样点数,定义为m1和m2;
启动点搜索算法可以解决如下问题:由于PIG在发球筒内受到压力,在进入可感知和可观察的运动状态之前,实际上有一个缓慢的加速运动过程,这个过程最多可以持续几十秒的时间,涉及的采样点数与两个子系统的采样频率有关,最多达到上万个(如图1和图6两图所示)。当直接采用人工标记的办法获得启动点时,在惯导和变径两个子系统的里程计原始数据图(如图1和图2)中先后判断启动点的采样点数,会产生0.1秒到10秒不等的误差。图6所示的两个可能的启动点A和B,在惯导子系统采样频率为500Hz时,换算成时间,相差能够达到5秒以上。而两个子系统同步操作的目标,是希望两个子系统的系统时钟面对同一时刻,输出时间的差值,即同步的时间精度goal_time,尽可能小。通过整个PIG内检测工程的目标测量精度逆推,两个子系统同步操作的时间精度goal_time必须低于0.1秒,因此无法忽略人工操作的误差。需要选择一种机器执行的状态跟踪方法,以同等尺度判断两张图的数据拐点,即启动点搜索算法。采用该搜索算法,可以在相同尺度下得到PIG两个子系统启动点时刻的精确采样点数,该数据对于两个子系统至关重要,实质性决定了最终基于时间的同步处理的精度。The starting point search algorithm can solve the following problems: due to the pressure of the PIG in the tee, before entering a perceptible and observable motion state, there is actually a slow acceleration motion process, which can last up to tens of seconds. , the number of sampling points involved is related to the sampling frequency of the two subsystems, which can reach tens of thousands at most (as shown in Figure 1 and Figure 6). When the starting point is directly obtained by the method of manual marking, the number of sampling points of the starting point is judged successively in the odometer original data map of the inertial navigation and variable diameter subsystems (as shown in Figure 1 and Figure 2), which will generate 0.1 seconds to 10 Errors ranging from seconds. The two possible starting points A and B shown in Figure 6, when the sampling frequency of the inertial navigation subsystem is 500 Hz, can be converted into time, and the difference can reach more than 5 seconds. The goal of the synchronous operation of the two subsystems is to hope that the system clocks of the two subsystems face the same moment, and the difference of the output time, that is, the synchronization time precision goal_time, is as small as possible. Through the inversion of the target measurement accuracy of the entire PIG detection project, the time accuracy goal_time of the synchronous operation of the two subsystems must be lower than 0.1 seconds, so the error of manual operation cannot be ignored. It is necessary to select a state tracking method executed by a machine to judge the data inflection points of the two graphs on the same scale, that is, to start the point search algorithm. Using this search algorithm, the exact number of sampling points at the start point of the two subsystems of PIG can be obtained at the same scale. This data is crucial to the two subsystems and substantially determines the final time-based synchronization processing accuracy.
启动点搜索算法必须使用惯导和变径两个子系统里程计的原始数据(如图1和图2),有其必要性。否则对惯导和变径的里程计原始数据进行去噪、颗粒化、柔化、数据转换等处理之后,会损失一些信息,而且不同子系统数据损失信息的情况也不一样,且很难评估,因此处理之后的数据不能保证在同一尺度下获得比较精确的启动点,必须使用原始数据。The starting point search algorithm must use the original data of the odometers of the two subsystems of inertial navigation and variable diameter (as shown in Figure 1 and Figure 2), which is necessary. Otherwise, some information will be lost after de-noising, granulation, softening, data conversion, etc. of the original data of inertial navigation and variable-path odometer, and the loss of information in different subsystems is also different, and it is difficult to evaluate , so the processed data cannot guarantee a more accurate starting point at the same scale, and the original data must be used.
所述启动点搜索算法如下:The starting point search algorithm is as follows:
1)确定搜索启动点算法的精度目标search_time,该精度必须和整个同步算法的精度目标相匹配,即搜索算法的精度目标比整个同步算法的精度目标高一个数量级,即搜索算法的误差时间search_time是同步算法误差时间goal_time的N分之一;1) Determine the accuracy target search_time of the search start point algorithm, which must match the accuracy target of the entire synchronization algorithm, that is, the accuracy target of the search algorithm is an order of magnitude higher than the accuracy target of the entire synchronization algorithm, that is, the error time search_time of the search algorithm is 1/N of the synchronization algorithm error time goal_time;
2)确定搜索步长step:定义某个子系统的采样频率(一秒钟的采样点个数)为sample_times,则搜索的步长为搜索启动点算法的精度目标乘以采样频率2) Determine the search step size step: Define the sampling frequency of a subsystem (the number of sampling points in one second) as sample_times, then the search step size is the accuracy target of the search start point algorithm multiplied by the sampling frequency
step=search_time×sample_timesstep=search_time×sample_times
搜索过程中,当第i次搜索的采样点数是mi,则第i+1次搜索的采样点数mi+1有During the search process, when the number of sampling points in the i-th search is m i , the number of sampling points in the i+1-th search m i+1 has
mi+1=mi+stepm i+1 =m i +step
3)图6为例定义搜索空间Ss:3) Fig. 6 defines the search space S s as an example:
Ss区间是采样点数组成的集合,是里程原始数据横坐标上的一段连续区间,由搜索的起点m_start和终点m_end定义;S s interval is a collection of sampling points, which is a continuous interval on the abscissa of the original mileage data, defined by the starting point m_start and the ending point m_end of the search;
定义Ss的原则是:保证搜索的目标,即启动点,在m_start和m_end之间。The principle of defining S s is to ensure that the search target, that is, the starting point, is between m_start and m_end.
设定Ss的方法如下:观察里程原始数据的图形,启动点必然处于平直区域向振荡区域的过渡区域,把这个过渡区域的左边界设定为m_start,例如m_start=195000,右边界设定为m_end,例如m_end=204000;The method of setting S s is as follows: observe the graph of the original mileage data, the starting point must be in the transition area from the flat area to the oscillating area, and the left boundary of this transition area is set to m_start, for example, m_start=195000, and the right boundary is set is m_end, for example m_end=204000;
m_start是开始搜索的采样点数,m_end是结束搜索的采样点数,进行后续的搜索计算,此时能够确定最大搜索次数Ns为m_start is the number of sampling points to start the search, and m_end is the number of sampling points to end the search. For subsequent search calculations, it can be determined that the maximum number of searches N s is
Ns=(m_end-m_start)/stepN s =(m_end-m_start)/step
令i为当前搜索的次数,定义搜索空间Let i be the number of current searches to define the search space
Ss={mi∣m_start≤mi≤m_end,i=1,2,…,Ns}S s ={m i ∣m_start≤m i ≤m_end,i=1,2,...,N s }
其中mi为第i次搜索的采样点数;where m i is the number of sampling points in the ith search;
4)确定发球筒内PIG的静置区间S;静置区间,即在子系统里程计原始信号图中标记的,PIG处于静置状态,没有微小移动的采样点数的集合区间,定义静置区间边界采样点数分别为ms0和ms1,则能够定义4) Determine the static interval S of the PIG in the serving cylinder; the static interval, that is, marked in the original signal diagram of the subsystem odometer, the PIG is in a static state, and the collection interval of the sampling points without slight movement, define the static interval The number of boundary sampling points is m s0 and m s1 respectively, then it can be defined
S={(m,SV)∣ms0≤m≤ms1}S={(m,S V )∣m s0 ≤m≤m s1 }
其中m为静置区间的采样点数,SV为m所对应的里程计原始信号;where m is the number of sampling points in the static interval, and S V is the original odometer signal corresponding to m;
以图1和图6所示,设定S的方法如下:在里程原始数据图上观察,从原点开始,图像会迅速趋于稳定,并进入一个平直的区域,该区域从横坐标看,将持续很多个采样点数,在这个平直区域中,图像只有高频的噪声信号,而不会出现纵坐标的较大起伏,把这个区域的左边界标记为采样点数ms0,右边界标记为采样点数ms1,例如ms0=1000,ms1=190000,这样定义的S区域保证了该时间段PIG以静止状态放置在发球筒中,不受其他因素干扰;As shown in Figure 1 and Figure 6, the method of setting S is as follows: Observe on the original mileage data map, starting from the origin, the image will quickly become stable and enter a flat area, which is viewed from the abscissa, It will last for a lot of sampling points. In this flat area, the image only has high-frequency noise signals, and there will be no large fluctuations in the ordinate. The left boundary of this area is marked as the number of sampling points m s0 , and the right boundary is marked as The number of sampling points m s1 , such as m s0 =1000, m s1 =190000, the S area defined in this way ensures that the PIG is placed in the ball cylinder in a static state during this time period, and is not disturbed by other factors;
在保证PIG处于静止状态的前提下,S区间应尽可能大,从统计意义上能够更精确的求出静置时SV的观测值,即静置区间S内所有SV的均值,定义为E(SV);On the premise of ensuring that the PIG is in a static state, the S interval should be as large as possible. In a statistical sense, the observed value of S V at rest can be more accurately obtained, that is, the mean value of all S V in the static interval S, which is defined as E(S V );
5)设置搜索中使用的参数:5) Set the parameters used in the search:
定义第i次搜索的目标采样点数为mi,mi∈Ss;Define the number of target sampling points for the i-th search as m i , where m i ∈ S s ;
定义第i次搜索时需要用到的两个集合:左集合(Sl)和右集合(Sr),定义左集合包含的采样点数为ml,定义右集合包含的采样点数为mr;两个集合Sl和Sr,他们分别是以当前搜索的采样点数mi为中心,位于mi左、右两侧的两个采样点集合,这两个集合内元素的个数设为1秒内的全部采样点的个数,即sample_times,有Define the two sets that need to be used in the ith search: the left set (S l ) and the right set (S r ), define the number of sampling points contained in the left set as m l , and define the number of sampling points contained in the right set as m r ; Two sets S l and S r , they are respectively the two sampling point sets located on the left and right sides of m i centered on the number of sampling points currently searched for m i , and the number of elements in these two sets is set to 1 The number of all sampling points in seconds, that is, sample_times, there are
Sl={(ml,SV)∣mi-sample_times≤ml≤mi,mi∈Ss}S l ={(m l ,S V )∣m i -sample_times≤m l ≤m i ,m i ∈S s }
Sr={(mr,SV)∣mi≤mr≤mi+sample_times,mi∈Ss}S r ={(m r ,S V )∣m i ≤m r ≤m i +sample_times,m i ∈S s }
两个集合全部SV的均值分别定义为El(SV)和Er(SV),即El(SV)为Sl内的全部SV的观测值,Er(SV)为Sr内的全部SV的观测值,当mi是启动点,则El(SV)必然趋近于E(SV),而Er(SV)必然大于E(SV);当mi不是启动点,则El(SV)和Er(SV)必然同样趋近于E(SV)或者同样大于E(SV); The mean values of all SVs of the two sets are defined as El (SV) and Er (SV) respectively, that is, El ( SV ) is the observed value of all SVs in Sl , and Er ( SV ) is the observed value of all S V in S r , when mi is the starting point, then El (S V ) must approach E(S V ), and E r (S V ) must be greater than E(S V ) ; When mi is not the starting point, then E l (S V ) and Er (S V ) must also approach E(S V ) or be greater than E(S V ) ;
当某次搜索采样点数mi=195005,则Sl范围表示如下:Sl={(ml,SV)∣194505≤ml≤195005};Sr范围表示如下:Sr={(mr,SV)∣195005≤mr≤195505};When the number of sampling points m i = 195005 in a certain search, the range of S l is expressed as follows: S l ={(m l ,S V )∣194505≤m l ≤195005}; the range of S r is expressed as follows: S r ={(m r ,S V )∣195005≤m r ≤195505};
定义本次搜索用于判定的两个门槛值εl和εr,初始设定的原则是εl>0,且尽可能小,而εr比εl大一个数量级,即εr比εl大M倍,M取2到10的整数;如果初始设定搜索得到的启动点多于1个,则减小εl并增加εr,重新搜索;Define the two threshold values ε l and ε r used for the determination of this search. The principle of initial setting is that ε l > 0, and it is as small as possible, and ε r is an order of magnitude larger than ε l , that is, ε r is larger than ε l M times larger, M is an integer from 2 to 10; if there are more than 1 starting point obtained by the initial search, decrease ε l and increase ε r , and search again;
6)在Ss范围内,从m_start开始,到m_end结束,搜索启动点,共进行Ns次搜索计算。对第i次搜索,i=1,2,…,Ns,当有6) Within the range of S s , start from m_start and end at m_end, search for the starting point, and perform a total of N s search calculations. For the ith search, i=1,2,...,N s , when there is
∣El(SV)-E(SV)∣<εl而且Er(SV)-E(SV)>εr ∣E l (S V )-E(S V )∣<ε l and E r (S V )-E(S V )>ε r
成立,则接受mi为启动点;当If established, accept m i as the starting point; when
∣El(mi)-E(SV)∣≥εl或者Er(mi)-E(SV)≤εr ∣E l (m i )-E(S V )∣≥ε l or E r (m i )-E(S V )≤ε r
成立,则需要对mi+1采样点数继续进行第i+1次搜索,其中mi+1=mi+step;If it is established, it is necessary to continue the i+1th search for the number of m i+1 sampling points, where m i+1 =m i +step;
7)如果上面的搜索完成,得到的启动点只有一个,则该子系统的启动点搜索算法结束,如果在整个Ss范围内,按照当前的εl和εr搜索,可以得到多个启动点,则需要调整εl和εr,重新进行搜索,直至剩下一个为止;调整的方法是,减小εl或者增加εr;该εl和εr必须在两个子系统的里程计原始数据中同时使用,分别得到启动点m1和m2;7) If the above search is completed and only one starting point is obtained, the starting point search algorithm of the subsystem ends. If the search is performed according to the current ε l and ε r in the entire S s range, multiple starting points can be obtained. , then you need to adjust ε l and ε r , and search again until there is one left; the adjustment method is to decrease ε l or increase ε r ; the ε l and ε r must be in the original odometer data of the two subsystems are used at the same time, and the starting points m1 and m2 are obtained respectively;
步骤三,根据变径和惯导两个子系统各自的采样频率sample_times,分别在变径和惯导两个子系统里程计原始信号图中求出每个采样点数m在各自系统时钟下的对应时间t,包括m1和m2在各自系统时钟中对应的时间t1和t2,如图3和图4的横坐标;Step 3: According to the respective sampling frequencies sample_times of the variable diameter and inertial navigation subsystems, obtain the corresponding time t of each sampling point m under the respective system clocks in the odometer original signal diagrams of the variable diameter and inertial navigation subsystems respectively. , including the corresponding times t1 and t2 of m1 and m2 in their respective system clocks, as shown in the abscissas of Figure 3 and Figure 4;
t=m/sample_timest=m/sample_times
把原来采样点数m的横轴转化为当前子系统时钟t的横轴;Convert the horizontal axis of the original number of sampling points m to the horizontal axis of the current subsystem clock t;
步骤四,求出t1和t2的差值Δt:Δt=t2-t1,Δt作为两个子系统时钟的差值,如图5所示;Step 4, find the difference Δt between t1 and t2: Δt=t2-t1, Δt is used as the difference between the two subsystem clocks, as shown in Figure 5;
步骤五,利用Δt,把两个子系统的时钟修正成同一时间,实现变径、惯导两个子系统数据的同步;Step 5: Use Δt to correct the clocks of the two subsystems to the same time to realize the synchronization of the data of the variable diameter and inertial navigation subsystems;
当需要把变径子系统时钟作为后续处理的标准时间时,则惯导子系统所有采样点的对应时间需要减Δt;当需要惯导子系统时间为标准时间时,则变径子系统的所有时间参数需要加Δt。When the variable diameter subsystem clock needs to be used as the standard time for subsequent processing, the corresponding time of all sampling points of the inertial navigation subsystem needs to be reduced by Δt; when the inertial navigation subsystem time is required to be the standard time, all the time parameters of the variable diameter subsystem Need to add Δt.
实际操作实例:Practical example:
步骤一:step one:
由步骤一得到图1,为典型惯导检测子系统里程的原始数据,横轴为采样点数,纵轴为包含了大量噪声的里程信号,该信号实质上是一个三角波电平,横轴上的m1为发球筒中惯导子系统启动点的采样点数,启动点附近的S区域在图6中放大;Figure 1 is obtained from
由步骤一得到图2为典型变径检测子系统里程的原始数据,横轴为采样点数,纵轴为包含了大量噪声的里程信号,该信号实质上是一个三角波电平,m2为发球筒中变径子系统启动点的采样点数。显然图2数据和图1数据波形完全一样,是同源数据,但需要进行同步。Figure 2 is the original data of the typical variable diameter detection subsystem mileage obtained from
步骤二:Step 2:
启动点搜索算法的必要性:The necessity of starting the point search algorithm:
图6为启动点附近S区域的信号,A(采样点数199246)、B(采样点数202419)都可能是启动点,采样频率为500Hz,此时A、B之间时间相差6.346秒,因此由于噪声等因素存在,人工方法很难精确定义m1点。Figure 6 shows the signal in the S area near the start point. Both A (sampling point number 199246) and B (sampling point number 202419) may be the start point. The sampling frequency is 500Hz. At this time, the time difference between A and B is 6.346 seconds. Therefore, due to noise and other factors, it is difficult to define the m1 point accurately by manual methods.
启动点搜索算法1)Start point search algorithm 1)
当两个子系统的同步精度goal_time,要求达到0.1秒,则搜索启动点算法的精度search_time应该在0.05到0.01秒之间;When the synchronization precision goal_time of the two subsystems is required to reach 0.1 seconds, the precision search_time of the search start point algorithm should be between 0.05 and 0.01 seconds;
启动点搜索算法2)Start point search algorithm 2)
采样频率500Hz,search_time=0.01,则step为5,Sampling frequency 500Hz, search_time=0.01, then step is 5,
启动点搜索算法3)Start point search algorithm 3)
如图6所示,可设定:m_start=195000,m_end=204000,Ns=1800。As shown in FIG. 6 , it can be set: m_start=195000, m_end=204000, and N s =1800.
启动点搜索算法4)Start point search algorithm 4)
如图1所示,可以确定ms0=1000,ms1=190000,E(SV)=1.772130As shown in Figure 1, it can be determined that m s0 =1000, m s1 =190000, E(S V )=1.772130
启动点搜索算法5)Start point search algorithm 5)
以图6数据为例,εl初始设定值为0.001,εr初始设定值为0.01。Taking the data in Figure 6 as an example, the initial setting value of ε l is 0.001, and the initial setting value of ε r is 0.01.
启动点搜索算法6)Start point search algorithm 6)
当第1次搜索,即i=1时,搜索采样点数m1=195000,Sl范围表示如下:Sl={(ml,SV)∣194500≤ml≤195000},得到El(SV)=1.772128;Sr范围表示如下:Sr={(mr,SV)∣195000≤mr≤195500},得到Er(SV)=1.772234。不满足Er(SV)-E(SV)>εr,因此不接受m1=195000为启动点。When the first search, that is, i=1, the number of search sampling points m 1 =195000, and the range of S l is expressed as follows: S l ={(m l ,S V )∣194500≤m l ≤195000}, and E l ( S V )=1.772128; the S r range is expressed as follows: S r ={(m r ,S V )∣195000≤m r ≤195500}, resulting in Er (S V )=1.772234. E r (S V )-E(S V )>ε r is not satisfied, so m 1 =195000 is not accepted as the starting point.
当第2次搜索,即i=2时,搜索采样点数m2=195005,Sl范围表示如下:Sl={(ml,SV)∣194505≤ml≤195005},得到El(SV)=1.772127;Sr范围表示如下:Sr={(mr,SV)∣195005≤mr≤195505},得到Er(SV)=1.772151。不满足Er(SV)-E(SV)>εr,因此不接受m2=195005为启动点。When the second search, i.e. i=2, the number of search sampling points m 2 =195005, the range of S l is expressed as follows: S l ={(m l ,S V )∣194505≤m l ≤195005}, and E l ( S V )=1.772127; the S r range is expressed as follows: S r ={(m r ,S V )∣195005≤m r ≤195505}, resulting in Er (S V )=1.772151. E r (S V )-E(S V )>ε r is not satisfied, so m 2 =195005 is not accepted as the starting point.
当第1640次搜索,即i=1640时,搜索采样点数m1640=203195,Sl范围表示如下:Sl={(ml,SV)∣202695≤ml≤203195},得到El(SV)=1.772517;Sr范围表示如下:Sr={(mr,SV)∣203195≤mr≤203695},得到Er(SV)=1.783518。符合判断条件,接受m1640=203195为启动点。When the 1640th search, i.e. i=1640, the number of search sampling points m 1640 =203195, the range of S l is expressed as follows: S l ={(m l ,S V )∣202695≤m l ≤203195}, and E l ( S V )=1.772517; the S r range is expressed as follows: S r ={(m r , S V )∣203195≤m r ≤203695}, resulting in E r (S V )=1.783518. If the judgment condition is met, m 1640 =203195 is accepted as the starting point.
启动点搜索算法7)Start point search algorithm 7)
完成1800次搜索,发现搜索到的启动点达到22个,不唯一,修改εr值为0.03,重新搜索,得到m1724=203615。Sl范围表示如下:Sl={(ml,SV)∣203115≤ml≤203615},得到El(SV)=1.772802;Sr范围表示如下:Sr={(mr,SV)∣203615≤mr≤204115},得到Er(SV)=1.803518。符合判断条件,接受m1724=203615为惯导子系统唯一启动点,即m1=203615。After completing 1800 searches, it is found that the searched starting points reach 22, which are not unique. Modify the value of ε r to 0.03, search again, and obtain m 1724 =203615. The range of S l is expressed as follows: S l ={(m l ,S V )∣203115≤m l ≤203615}, and E l (S V )=1.772802 is obtained; the range of S r is expressed as follows: S r ={(m r , S V )∣203615≤m r ≤204115}, E r (S V )=1.803518 is obtained. If the judgment conditions are met, m 1724 = 203615 is accepted as the only starting point of the inertial navigation subsystem, that is, m1 = 203615.
类似方法可得到m2=106710。In a similar way, m2=106710 can be obtained.
步骤三:Step 3:
由步骤三得到图3,为典型惯导子系统的输出数据,横轴为时间,纵轴为里程,单位米。t1为惯导子系统时钟标准下,由m1计算得到的惯导子系统在发球筒中经过启动点的时间407.23秒。Figure 3 is obtained from
由步骤三得到图4,为典型变径子系统的输出数据,横轴为时间,纵轴为里程,单位米。t2为变径子系统时钟标准下,由m2计算得到的变径子系统在发球筒中经过启动点的时间213.42秒。Figure 4 is obtained from
从图3、4可以看到,因为对原始数据进行滤波等处理,很多低速区间的里程数据“消失”了,如果此时求启动点,则启动点会发生“移动”,而且移动的距离并不一致,因此必须使用原始数据搜索启动点。As can be seen from Figures 3 and 4, many mileage data in the low-speed range "disappeared" due to the filtering and other processing of the original data. If the starting point is found at this time, the starting point will "move", and the distance moved does not equal Inconsistent, so the starting point must be searched using the raw data.
步骤四:Step 4:
由步骤四得到图5,把典型变径检测子系统和惯导检测子系统输出的里程数据放在一个坐标系内,Δt为变径和惯导两个子系统时钟的同步误差,得到Δt=210.08秒。Figure 5 is obtained from step 4. The mileage data output by the typical variable diameter detection subsystem and the inertial navigation detection subsystem are placed in a coordinate system, Δt is the synchronization error of the two subsystem clocks of the variable diameter and inertial navigation, and Δt=210.08 second.
步骤五:Step 5:
以变径时钟为标准,则所有的惯导输出数据(包括但不限于里程数据)对应的时间须减去210.08秒。Taking the variable diameter clock as the standard, the time corresponding to all inertial navigation output data (including but not limited to mileage data) must be subtracted by 210.08 seconds.
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