Laser ranging method and system

Abstract

The present invention relates to the field of laser ranging technology, and specifically to a laser ranging method and system. The method includes: using a laser rangefinder at a first location to emit a laser beam to a first point to be measured, and collecting first laser transceiver data; calculating a first relative position of the first point to be measured; using a laser rangefinder at a second location to emit a laser beam to a second point to be measured, and collecting second laser transceiver data; calculating a second relative position of the second point to be measured; respectively calculating multiple target distances between the first and second points to be measured; calculating the degree of difference between any target distance D1 and the remaining distances D2, and when the degree of difference falls within a second threshold range, identifying the target distance D1 as a qualified measurement value. The laser ranging technology provided by the present invention allows a user to directly measure the distance between two points even if they are standing at a third point other than the two points, thereby improving the flexibility and convenience of ranging.

Description

Technical Field

[0001] The present invention relates to the technical field of laser ranging, and in particular to a laser ranging method and system. Background Art

[0002] Laser distance measuring uses a laser as a light source for distance measurement. Lasers are categorized by their operating mode into continuous lasers and pulsed lasers. For example, gas lasers such as helium-neon, argon-ion, and krypton-cadmium can be used in continuous-wave laser ranging for phase-shifted laser ranging. Solid-state lasers such as ruby ​​and neodymium glass can be used in pulsed laser ranging.

[0003] For example, patent application CN119620095A discloses a laser ranging method and device based on a posture sensor. The method includes: S1, when measuring the straight-line distance between a first measured point and a second measured point, measuring a first distance value at a first emission point; S2, obtaining first spatial coordinate information and first angle information through the posture sensor; S3, after moving from the first emission point to the second emission point, measuring a second distance value at the second emission point; S4, obtaining second spatial coordinate information and second angle information through the posture sensor; S5, calculating the spatial coordinate information of the first measured point and the spatial coordinate information of the second measured point based on the first spatial coordinate information, the first angle information, and the first distance value using a spatial posture angle conversion algorithm; S6, calculating the straight-line distance value between the first measured point and the second measured point. This ranging method does not require laser ranging at one of the two measured points, thereby improving the efficiency and convenience of the laser ranging process.

[0004] For another example, patent application CN105589076A discloses a remote two-point distance measuring device and a measurement method thereof, wherein the distance measuring device comprises: a rod body, an angle measurement module, a distance measuring module and a calculation and control module; the angle measurement module comprises: a flat plate; the flat plate is connected to the rod body and is provided with an angle scale; a fixed end fixed to the flat plate; a mobile end having one end hinged to the flat plate; the distance measuring module comprises: a laser distance measuring tube, which is fixed to and parallel to the mobile end; the calculation and control module is connected to the angle measurement module and the distance measuring module through a circuit, and receives distance information and angle information to achieve two-point distance measurement.

[0005] However, the applicant has noticed that traditional measurement solutions are often suitable for indoor measurements. In outdoor measurement environments, measurement data is very easily affected by the environment, resulting in inaccurate measurements.

[0006] Therefore, there is an urgent need for a laser measurement technology suitable for outdoor measurement. Summary of the Invention

[0007] The object of the present invention is to provide a laser ranging method to partially solve or alleviate the above-mentioned deficiencies in the prior art, thereby improving the accuracy of ranging, and in particular reducing or alleviating errors caused by human factors or environmental factors.

[0008] In order to solve the above-mentioned technical problems, the present invention specifically adopts the following technical solutions:

[0009] A first aspect of the present invention is to provide a laser ranging method, comprising the steps of:

[0010] Obtaining a measurement position, where the measurement position is a first relative position or a second relative position; wherein the step of obtaining the measurement position includes:

[0011] At a first location, a laser rangefinder is used to emit a laser beam to a first point to be measured, and first laser transceiver data is collected;

[0012] Calculating a first relative position of the first point to be measured based on the first laser transceiver data;

[0013] At a second location, the laser rangefinder is used to emit a laser beam to a second point to be measured, and second laser transmission and reception data is collected;

[0014] Calculating a second relative position of the second point to be measured based on the second laser transceiver data;

[0015] At least three target distances are calculated based on at least three groups of measurement positions, wherein one group of measurement positions includes a first relative position and a second phase position;

[0016] Calculate the difference L2 between any one target distance D1 and at least one other target distance D2; L2 = (D1-D2) / reference distance value; wherein the reference distance value is D1 or D2;

[0017] When the degree of difference falls within a second threshold range, the target distance D1 is identified as a qualified measurement value;

[0018] A recommended measurement result is generated based on the qualified measurement value.

[0019] In some embodiments, a measurement position, such as a first relative position or a second relative position, is obtained using a reduction error method, which includes the steps of:

[0020] S1011, using the laser rangefinder to emit a visible light beam to the corresponding point to be measured;

[0021] S1012, obtaining a first motion acceleration of the laser rangefinder in a first time period;

[0022] S1013, generating first jitter data according to the first motion acceleration;

[0023] S1014: When the first jitter data is less than a first jitter threshold, marking the corresponding first time period as a first-class time period;

[0024] S1015, determining whether the total duration of the currently continuously generated time period of the type is greater than a first duration threshold, if so, proceeding to S1016;

[0025] S1016, using the laser rangefinder to emit a laser beam to the first point to be measured or the second point to be measured during a second time period, and recording corresponding laser emission and reception data;

[0026] S1017: Calculate at least one of the measurement positions of the first point to be measured or the second point to be measured in the second time period according to the laser emission and reception data, and mark the measurement position with a time tag.

[0027] In some embodiments, the step of calculating the target distance includes:

[0028] Screening out at least one first target point from the plurality of first relative positions, and screening out at least one second target point from the plurality of second relative positions;

[0029] At least one target distance is calculated based on the at least one first target point and the at least one second target point.

[0030] In some embodiments, the measurement position is marked with a time tag. Before calculating the measurement position, the method further includes the steps of performing a second type of filtering operation on the measurement position; the second type of filtering operation includes the steps of:

[0031] Obtaining second motion accelerations recorded by the laser rangefinder at multiple moments in the second time period;

[0032] generating second jitter data according to the second motion acceleration;

[0033] When the second jitter data is greater than a second jitter threshold, the measurement position corresponding to the moment is identified as a second-type abnormal point;

[0034] Calculate the second adjacent time interval of at least two adjacent second-category abnormal points;

[0035] When the second adjacent time intervals between the plurality of the second-category abnormal points are all less than the preset second time interval, the corresponding plurality of the second-category abnormal points are identified as a second filtering point set;

[0036] Obtaining a first moment of a leading abnormal point and a second moment of a trailing abnormal point in the second filter point set;

[0037] A measurement position outside the interval from the first time to the second time is identified as a target point.

[0038] In some embodiments, the measurement position is marked with a time tag, and before calculating the measurement position, the method further includes the following steps:

[0039] calculating a difference between at least two adjacent measurement positions;

[0040] Identifying at least one of the measurement locations where the difference is greater than a preset first threshold as a type of abnormal point;

[0041] Obtaining the first adjacent time interval of at least two adjacent abnormal points of the same type;

[0042] When the first adjacent time intervals between the plurality of abnormal points of the first type are all less than a preset first time interval, the corresponding plurality of abnormal points of the first type are identified as a first filtering point set;

[0043] Obtaining the third moment of the first abnormal point and the fourth moment of the last abnormal point in the first filter point set;

[0044] A relative position outside the interval from the third moment to the fourth moment is identified as a target point.

[0045] In some embodiments, before calculating the first relative position or calculating the second relative position, the method further includes the steps of:

[0046] Obtaining a target curve generated by the target point and the corresponding time;

[0047] Smoothing the target curve to obtain a new target curve;

[0048] Calculate position feature values ​​of multiple points in the new target curve, and use the position feature values ​​as the first relative position or the second relative position, wherein the position feature value is an average value, a mode, or a median of the positions of the multiple points.

[0049] In some embodiments, the smoothing process includes one or more of the following:

[0050] Moving average method, Gaussian filter, median filter, Kalman filter.

[0051] In some embodiments, further comprising:

[0052] Acquire a first distance value and a second distance value generated by the laser emission and reception data, wherein the first distance value is the distance between the first point to be measured and the first location, and the second distance value is the distance between the second point to be measured and the second location;

[0053] Calculate the difference L1 between the first distance value and the second distance value. The calculation rule of the difference L1 is:

[0054] L1=(first distance value-second distance value) / reference distance value; wherein the reference distance value is the first distance value or the second distance value;

[0055] When the difference level L1 falls within a first threshold range, a first prompt signal is issued, where the first prompt signal is used to remind the user to pay attention to whether the laser emission path of the laser rangefinder is blocked.

[0056] The present invention also provides a laser ranging system, comprising:

[0057] A measurement module is used to obtain a measurement position, where the measurement position is a first relative position or a second relative position; the measurement module includes:

[0058] The measurement submodule is configured to use a laser rangefinder to emit a laser beam to a first point to be measured at a first location and collect first laser transceiver data; and use the laser rangefinder to emit a laser beam to a second point to be measured at a second location and collect second laser transceiver data;

[0059] a first calculation submodule, configured to calculate a first relative position of the first point to be measured based on the first laser transceiver data; and to calculate a second relative position of the second point to be measured based on the second laser transceiver data;

[0060] a second calculation submodule, configured to calculate at least three target distances according to at least three groups of measurement positions, wherein one group of measurement positions includes a first relative position and a second phase position;

[0061] A difference evaluation submodule is configured to calculate a difference L2 between any one target distance D1 and at least one other target distance D2; L2 = (D1-D2) / reference distance value; wherein the reference distance value is D1 or D2;

[0062] A difference evaluation module is configured to calculate a difference L2 between any one target distance D1 and at least one other target distance D2; L2 = (D1-D2) / reference distance value; wherein the reference distance value is D1 or D2;

[0063] a qualified identification module, configured to identify the target distance D1 as a qualified measurement value when the difference degree falls within a second threshold range;

[0064] A recommendation output module is used to generate a recommended measurement result according to the qualified measurement value.

[0065] In some embodiments, further comprising:

[0066] The rotation speed measurement module is used to emit a light source to the surface of the object to be measured. When the object to be measured rotates, the reflective sheet of the object to be measured will reflect the corresponding reflected light, and the rotation speed of the object to be measured is calculated based on the received reflected light.

[0067] Beneficial technical effects:

[0068] The present invention provides a two-point ranging method suitable for use in complex environments. In particular, it is suitable for two-point ranging in outdoor scenarios. The applicant has noted that ranging in complex environments, especially outdoor environments, may face multiple interferences caused by the superposition of human and environmental factors. In response to this, the present application provides a step-by-step, hierarchical data filtering technology for different measurement stages (such as the data acquisition stage, the data processing stage, and the data calculation stage). This data filtering technology can, on the one hand, comprehensively reduce the interference caused by human and environmental factors on the measurement, while at the same time retaining more reliable data to a greater extent, thereby avoiding the filtering process having an adverse effect on data reliability.

[0069] Specifically, for the data acquisition stage, the present invention provides an error reduction measurement technology to try to filter out the deviation caused by the vibration of the rangefinder in the early stage of laser transmission and reception.

[0070] During the data processing phase, the present invention provides two types of filtering operations based on jitter level to address human error. This significantly reduces human error in the early stages of data calculation. Furthermore, a localized, overall filtering of a series of data points is performed directly based on the time intervals when jitter level was generated, significantly minimizing or reducing the adverse interference caused by jitter on the data.

[0071] In the data processing stage, the present invention also provides a type of filtering operation based on data difference to address comprehensive errors such as human errors and environmental errors (such as flight obstacles). In this type of filtering operation, the present invention further performs local overall filtering on data in frequently fluctuating time intervals based on the density of abnormal points.

[0072] Preferably, the second type of filtering operation may be performed first, and then the first type of filtering operation may be performed on the data obtained based on the second type of filtering operation.

[0073] Preferably, before smoothing the data, the present invention sequentially performs a second-class filtering operation and a first-class filtering operation to extract and filter a large number of measurement points in a fragmented manner, thereby eliminating localized data with excessive error interference. This pre-processing, fragmented filtering can reduce the difficulty of the smoothing process and prevent interference with the smoothing process (or, in other words, ensure that the number of outliers in the core data being smoothed is relatively controllable), thereby improving the accuracy and reliability of the smoothing process.

[0074] Furthermore, with respect to the data calculation stage, the present invention also provides a method for filtering data by comprehensively considering the measurement differences between the first and second measured points (such as the degree of difference between the first relative position and the second relative position), so as to further reduce or alleviate the interference of human operations on the measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the embodiments or the description of the prior art. In all drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the various elements or parts are not necessarily drawn according to the actual scale. Obviously, the drawings described below are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without inventive work.

[0076] Figure 1 1 is a flow chart of a laser ranging method in an exemplary embodiment of the present invention;

[0077] Figure 2 1 is a schematic diagram of an error reduction process for laser ranging in an exemplary embodiment of the present invention;

[0078] Figure 3 Schematic diagram of the filtering process of laser ranging in an exemplary embodiment of the present invention;

[0079] Figure 4 Schematic diagram of the module structure of a laser ranging system in an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0080] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0081] Herein, suffixes such as "module," "component," or "unit" used to represent elements are only used to facilitate description of the present invention and have no specific meaning. Therefore, "module," "component," or "unit" may be used interchangeably.

[0082] As used herein, terms such as "upper," "lower," "inner," "outer," "front," "back," "one end," and "the other end" indicate positions or locations based on those shown in the accompanying drawings. These terms are intended solely to facilitate and simplify the description of the present invention and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0083] As used herein, unless otherwise expressly specified or limited, the terms "installed," "provided with," and "connected" should be understood broadly. For example, "connected" may refer to a fixed connection, a detachable connection, or an integral connection; it may refer to a mechanical connection, a direct connection, an indirect connection via an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention on a case-by-case basis.

[0084] As used herein, "and / or" includes any and all combinations of one or more of the associated listed items.

[0085] Herein, "plurality" means two or more than two, ie, it includes two, three, four, five, etc.

[0086] As used in this specification, the term "about" typically means + / - 5% of the stated value, more typically + / - 4% of the stated value, more typically + / - 3% of the stated value, more typically + / - 2% of the stated value, even more typically + / - 1% of the stated value, and even more typically + / - 0.5% of the stated value.

[0087] In this specification, certain embodiments may be disclosed in a format that is within a range. It should be understood that this description of "within a range" is merely for convenience and brevity and should not be interpreted as a rigid limitation on the disclosed range. Therefore, the description of a range should be considered to have specifically disclosed all possible subranges and individual numerical values ​​within this range. For example, the description of a range of 1-6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as individual numbers within this range, such as 1, 2, 3, 4, 5, and 6. Regardless of the breadth of the range, the above rules apply.

[0088] Example 1

[0089] See also Figure 1 As shown, the present invention provides a laser ranging method, comprising the steps of:

[0090] Obtaining a measurement position, where the measurement position is a first relative position or a second relative position; wherein the step of obtaining the measurement position includes:

[0091] At a first location, a laser rangefinder is used to emit a laser beam to a first point to be measured, and first laser transceiver data is collected;

[0092] Calculating a first relative position of the first point to be measured based on the first laser transceiver data;

[0093] It should be noted that in some embodiments of the present invention, the measurement position is collectively referred to as the first relative position and the second relative position, or the measurement position can also be referred to as the relative position. The measured point can be collectively referred to as the first measured point and the second measured point.

[0094] For example, in some embodiments, a laser rangefinder is used to emit at least one laser beam to a first point to be measured, and the coordinates of the first point (for example, the current coordinate position of the laser rangefinder) and the emission angle are recorded, and the reception time of the reflected laser signal is recorded, so that the distance between the emission position and the first point to be measured can be calculated according to the pulse method or the phase method, or in other words, the relative positional relationship between the first point to be measured and the emission position can be calculated.

[0095] For example, in some embodiments, the relative position can be described by the distance between the point to be measured and the site.

[0096] Alternatively, in some embodiments, the relative position may be described using the spatial coordinates of the point to be measured.

[0097] At a second location, the laser rangefinder is used to emit a laser beam to a second point to be measured, and second laser transmission and reception data is collected;

[0098] Calculating a second relative position of the second point to be measured based on the second laser transceiver data;

[0099] Preferably, the second relative position of the second point to be measured can be acquired by adopting the same measurement method as that for the first relative position.

[0100] The target distance (or measurement result) is calculated based on the at least one first relative position and the at least one second relative position, that is, the distance between the first point to be measured and the second point to be measured is calculated.

[0101] In this embodiment, by obtaining the coordinates of the first point and the second point (such as the relative position relationship between the two), the coordinates of the relative positions of the first measured point and the second measured point are obtained at the same time, and then the distance between the two measured points can be indirectly calculated through spatial coordinate conversion.

[0102] In some embodiments, the coordinates or relative positional relationship between the first and second points can be measured using a posture sensor. For example, the posture sensor can be a high-precision inertial measurement unit (IMU), which is a six-axis sensor including a three-axis gyroscope and a three-axis accelerometer. The accelerometer detects acceleration signals, while the gyroscope detects angular velocity signals. The angular velocity and acceleration of the photometric rangefinder in three-dimensional space are measured and used to calculate the posture of the laser rangefinder. This allows the tilt and rotation information of the laser rangefinder to be captured in real time, allowing precise positioning of the spatial position and orientation.

[0103] In some embodiments, the laser rangefinder may adopt the laser rangefinder disclosed in patent application 202411796303.9.

[0104] Furthermore, in some embodiments, the step of calculating the target distance according to the at least one first relative position and the at least one second relative position includes:

[0105] At least three target distances are calculated based on at least three groups of measurement positions, wherein one group of measurement positions includes a first relative position and a second phase position;

[0106] Calculate the difference L2 between any one target distance D1 and at least one other target distance D2; L2 = (D1-D2) / reference distance value; wherein the reference distance value is D1 or D2;

[0107] When the difference falls within the second threshold range, the target distance D1 is identified as a qualified measurement value; otherwise, the target distance D1 can be identified as an unqualified measurement value (i.e., an abnormal point).

[0108] A recommended measurement result is generated based on the qualified measurement value.

[0109] Furthermore, in some embodiments, the step of generating a recommended measurement result according to the qualified measurement value includes:

[0110] Calculate the characteristic values ​​of at least two qualified measurement values ​​and use the characteristic values ​​as the recommended measurement results.

[0111] Preferably, a plurality of qualified measurement values ​​are obtained, and the characteristic value is the average or mode of the plurality of qualified measurement values.

[0112] This embodiment provides an error filtering method. Specifically, during the actual measurement process, multiple groups of lasers can be emitted in a short period of time, multiple target distances can be calculated accordingly, and abnormal points can be filtered out.

[0113] It is understood that the laser ranging method provided by the present invention is capable of two-point distance measurement. That is, a user can stand at a position other than the second measured point to measure the distance between the first and second measured points. For example, the laser ranging method can be used to measure the distance between two walls.

[0114] However, the applicant has noted that in complex environments, environmental changes may interfere with the measurement results. For example, taking the measurement of the distance between two buildings as an example, the user can stand between the two buildings and use a laser rangefinder to emit multiple laser beams back and forth at the two opposite walls of the two buildings, and calculate multiple target distances accordingly. The error filtering method provided by the present invention can avoid or reduce the impact of errors. For example, when the laser beam encounters a fault object, such as a flying object (such as a bird, fallen leaves or drone, etc.), the target distance value measured at that moment will suddenly become smaller (such as the distance between the first point to be measured and the flying object is actually measured at this time). Therefore, the abnormal point can be eliminated by filtering to improve accuracy.

[0115] In some embodiments, the method includes measuring the relative positions using a reduced error method. Specifically, the reduced error method is used to obtain at least one first relative position of the first point to be measured and at least one second relative position of the second point to be measured using a laser rangefinder (i.e., obtaining the measured positions using the reduced error method).

[0116] Specifically, see Figure 2 As shown, the steps of measuring the relative position using the error reduction method include:

[0117] S1011, using the laser rangefinder to emit a visible light beam to the corresponding point to be measured;

[0118] For example, in some embodiments, the visible light beam may be a red light. The visible light beam serves as an auxiliary positioning means, and the user can determine the position of the selected point to be measured by the incident position of the visible light beam.

[0119] S1012, obtaining a first motion acceleration (for example, an angular rotation acceleration) of the laser rangefinder in a first time period;

[0120] For example, in some embodiments, the jitter of the laser rangefinder can be measured based on a three-axis gyroscope and a three-axis accelerometer.

[0121] S1013, determining first jitter data according to the first motion acceleration;

[0122] For example, in some embodiments, the first motion acceleration is an angular rotational acceleration, or the first motion acceleration is a velocity of position change. Accordingly, the first jitter data can be directly represented by the first motion acceleration. Alternatively, in some embodiments, the first jitter data can be an average value of the first motion acceleration.

[0123] S1014: When the first jitter data is less than a first jitter threshold, the corresponding first time period is marked as a first-class time period. Typically, when the laser rangefinder is relatively stationary, the time period is marked as a first-class time period.

[0124] S1015: Determine whether the total duration of the currently continuously generated time period of the type is greater than a first duration threshold. If so, proceed to S1016. Alternatively, in some other embodiments, if S1015 is negative, it may be considered that the laser rangefinder may be experiencing jitter, resulting in significant errors in the collection of laser emission and reception data. Therefore, in some embodiments, laser emission is not performed or the collection of laser emission and reception data is not performed in this case.

[0125] S1016, using the laser rangefinder to emit a laser beam to the first point to be measured or the second point to be measured during a second time period, and recording corresponding laser emission and reception data;

[0126] For example, in some embodiments, the laser beam can be arranged parallel to the visible light beam to facilitate the user's naked eye observation of the positioning. Alternatively, the laser beam can be approximately parallel to the visible light beam.

[0127] That is to say, preferably, data recording of the laser beam is started only when the laser rangefinder is in a state close to being relatively stationary, so as to filter out or avoid adverse effects of jitter on the measurement results.

[0128] S1017: Calculate at least one of the measurement positions of the first point to be measured or the second point to be measured in the second time period according to the laser emission and reception data, and mark the measurement position with a time tag.

[0129] For example, in some embodiments, the laser rangefinder is provided with a laser beam emission switch (e.g., a push-button switch or a touch-sensitive key on the laser rangefinder's display screen). When a user presses or clicks the switch, the laser beam can be activated in response to the switch signal. However, the pressing force may cause the laser rangefinder to experience a certain degree of jitter, thereby resulting in errors in the measurement and collection of laser beam data (e.g., emission angle).

[0130] In this regard, the error reduction measurement technology proposed in this embodiment can select the data collection moment to reduce error interference caused by manual operation of the user.

[0131] For another example, in some embodiments, the user may select different points to be measured for testing in the early stage. In this case, the laser rangefinder will often move with the user's manual operation, thereby generating a certain degree of jitter.

[0132] In some embodiments, the step of calculating the target distance includes:

[0133] Screening out at least one first target point from the plurality of first relative positions, and screening out at least one second target point from the plurality of second relative positions;

[0134] At least one target distance is calculated based on the at least one first target point and the at least one second target point.

[0135] Preferably, in some embodiments, when a user performs a relative position measurement of a first point to be measured, the laser beam can be repeatedly emitted multiple times within a short period of time to obtain multiple relative positions, and a suitable point can be selected from the multiple relative positions as the target point. In particular, due to the speed characteristics of the laser, hundreds or even thousands of relative positions can be measured in just 1 second. The filtering operation proposed in this application can comprehensively process these hundreds or thousands of relative positions to obtain a reliable measurement result.

[0136] For example, when a laser beam starts from a laser rangefinder, passes through a point to be measured, and returns to the laser rangefinder again, if it is affected by obstacles in the middle, such as interference from fallen leaves or flying birds, the first relative position obtained at that moment may be different from the first relative position under normal circumstances. In this regard, the present invention provides a dual-type filtering operation to eliminate or mitigate the error.

[0137] In some embodiments, see Figure 3 As shown, before calculating the first relative position or calculating the second relative position (that is, before calculating the measured position), the method further includes the steps of performing a second type of filtering operation on the measured position; which includes the steps of:

[0138] Obtaining second motion accelerations recorded by the laser rangefinder at multiple moments in the second time period;

[0139] generating second jitter data according to the second motion acceleration;

[0140] When the second jitter data is greater than a second jitter threshold, the measurement position corresponding to the moment is identified as a second-type abnormal point;

[0141] Calculate the second adjacent time interval of at least two adjacent second-category abnormal points;

[0142] When the second adjacent time intervals between the plurality of the second-category abnormal points are all less than the preset second time interval, the corresponding plurality of the second-category abnormal points are identified as a second filtering point set;

[0143] Obtain the first moment of the head abnormal point and the second moment of the tail abnormal point in the second filter point set; for example, in some embodiments, there may be normal points between multiple second-category abnormal points, then the abnormal points and normal points in the time interval can be locally eliminated, that is, the measurement points in the local time interval are filtered.

[0144] A measurement position outside the interval from the first time to the second time is identified as a target point.

[0145] In other words, in this embodiment, the measurement results (or measurement points) within the time interval may be filtered and not included in the final target distance calculation process.

[0146] For example, in this embodiment, when abnormal jitter is detected during a second time period (e.g., a measurement period) (e.g., when the second jitter data is greater than a second jitter threshold), the measurement data (e.g., relative position) generated at the corresponding time is identified as a Class II abnormal point. Furthermore, if multiple Class II abnormal points occur at similar times within a certain time period, all measurement data within the time interval covered by these multiple Class II abnormal points can be filtered out (or, in other words, eliminated in a fragmented manner).

[0147] Therefore, in this embodiment, errors caused by human factors are actually eliminated from the user's manual operation level.

[0148] In some embodiments, before calculating the measured position, the method further includes the steps of performing a filtering operation on the relative position; the filtering operation includes the steps of:

[0149] calculating a difference between at least two adjacent measurement positions;

[0150] Identifying at least one of the measurement locations where the difference is greater than a preset first threshold as a type of abnormal point;

[0151] For example, in some embodiments, when two data points with large differences (ie, relative positions) are identified, both data points may be considered as outliers.

[0152] Obtaining the first adjacent time interval of at least two adjacent abnormal points of the same type;

[0153] When the first adjacent time intervals between the plurality of abnormal points of the first type are all less than a preset first time interval, the corresponding plurality of abnormal points of the first type are identified as a first filtering point set;

[0154] Obtaining the third moment of the first abnormal point and the fourth moment of the last abnormal point in the first filter point set;

[0155] The measured positions outside the interval from the third time to the fourth time are identified as target points.

[0156] That is, in this embodiment, when multiple abnormal points of the first type are generated relatively densely within a period of time, the data in the local time period can be filtered as a whole (or, in other words, segmented filtering).

[0157] In this embodiment, both human and environmental causes are eliminated comprehensively from the perspective of environmental interference.

[0158] Of course, this type of filtering operation can also eliminate erroneous data points caused by environmental obstacles.

[0159] In some embodiments, before calculating the first relative position or calculating the second relative position (that is, before calculating the measured position), the method further includes the following steps:

[0160] Obtaining a target curve generated by the target point and the corresponding time;

[0161] Smoothing the target curve to obtain a new target curve;

[0162] Calculate position feature values ​​of multiple points in the new target curve, and use the position feature values ​​as the first relative position or the second relative position, wherein the position feature value is an average value, a mode, or a median of the positions of the multiple points.

[0163] In this embodiment, with respect to a large amount of relative position measurement results, it is preferred to identify them as curves, and further screen and filter the data using smoothing processing.

[0164] It's worth noting that the present invention employs dual or multi-layer filtering techniques (or smoothing techniques) to comprehensively screen massive amounts of relative position data points. One or two types of filtering can eliminate significant outliers before smoothing the curve, reducing the difficulty of the smoothing process. Alternatively, employing one or two types of filtering for pre-processing can prevent large errors from misleading the smoothing process, thereby improving the reliability of the smoothing process.

[0165] In some embodiments, the smoothing process includes one or more of the following:

[0166] Moving average method, Gaussian filter, median filter, Kalman filter.

[0167] In some embodiments, further comprising:

[0168] Acquire a first distance value and a second distance value generated by the laser emission and reception data, wherein the first distance value is the distance between the first point to be measured and the first location, and the second distance value is the distance between the second point to be measured and the second location;

[0169] Calculate the difference L1 between the first distance value and the second distance value. The calculation rule of the difference L1 is:

[0170] L1=(first distance value-second distance value) / reference distance value; wherein the reference distance value is the first distance value or the second distance value;

[0171] When the difference level L1 falls within a first threshold range, a first prompt signal is issued, where the first prompt signal is used to remind the user to pay attention to whether the laser emission path of the laser rangefinder is blocked.

[0172] For example, since the laser may be invisible or difficult to observe with the naked eye, when the user wears long-sleeved clothing with large cuffs and the user's operation angle is improper, the laser beam may be directly blocked by the sleeves. In this regard, the differential comparison of distance values ​​can avoid or reduce the erroneous interference caused by improper operation.

[0173] Preferably, in order to solve the sleeve occlusion problem, the present invention can also provide intelligent prompts to the user in the early stage of measurement.

[0174] For example, users typically stand between a first and second measurement point to measure, meaning the distance deviation between the first and second measurement points is often significant. Therefore, if a significant distance deviation is detected between the user's current location and both the first and second measurement points—for example, if the user is ten meters from the first measurement point but only eight centimeters from the second—then it's suspected that occlusion interference may have occurred during the laser transmission between the two measurement points.

[0175] For example, in some embodiments, the prompt signal may be in the form of a signal light, or it may be in the form of a voice notification.

[0176] For another example, in some embodiments, the laser rangefinder is provided with a display screen, which can electronically display relevant data, for example, it can output the final measurement result. For another example, when there is an improper operation, the display screen can give an error signal prompt.

[0177] Furthermore, in some embodiments, the display screen may also have interactive functions, whereby a user can provide corresponding operation signals by touching the display screen. For example, electronic selection buttons are provided on the display screen, such as selection boxes for turning on the visible beam, turning on the laser beam, and calculating the distance. The user can use the electronic display screen to perform two-point distance measurement operations with one hand.

[0178] Example 2

[0179] See also Figure 4 As shown, the present invention also provides a laser ranging system, comprising:

[0180] A measurement module is used to obtain a measurement position, where the measurement position is a first relative position or a second relative position; the measurement module includes:

[0181] The measurement submodule is configured to use a laser rangefinder to emit a laser beam to a first point to be measured at a first location and collect first laser transceiver data; and use the laser rangefinder to emit a laser beam to a second point to be measured at a second location and collect second laser transceiver data;

[0182] a first calculation submodule, configured to calculate a first relative position of the first point to be measured based on the first laser transceiver data; and to calculate a second relative position of the second point to be measured based on the second laser transceiver data;

[0183] a second calculation submodule, configured to calculate at least three target distances according to at least three groups of measurement positions, wherein one group of measurement positions includes a first relative position and a second phase position;

[0184] A difference evaluation submodule is configured to calculate a difference L2 between any one target distance D1 and at least one other target distance D2; L2 = (D1-D2) / reference distance value; wherein the reference distance value is D1 or D2;

[0185] a qualified identification module, configured to identify the target distance D1 as a qualified measurement value when the difference degree falls within a second threshold range;

[0186] A recommendation output module is used to generate a recommended measurement result according to the qualified measurement value.

[0187] It is understandable that the present invention can implement the methods or steps described in any one of the above embodiments, which will not be described in detail here.

[0188] In some embodiments, the system further comprises:

[0189] The rotation speed measurement module is used to emit a light source to the surface of the object to be measured. When the object to be measured rotates, the reflective sheet of the object to be measured will reflect the corresponding reflected light, and the rotation speed of the object to be measured is calculated based on the received reflected light.

[0190] That is to say, based on the rotation speed measurement module, the rangefinder can also measure the motion condition of the moving object, such as the rotation speed.

[0191] For example, in some embodiments, the further working process of the rotation speed measurement module is as follows:

[0192] The laser beam is emitted at set intervals. When the laser beam encounters the reflective sheet of the object to be measured, a reflected beam is generated. The reflected beam is then received by the speed measurement module, which also records the incident angle of the reflected beam.

[0193] Among them, since the object to be measured is in the process of rotation, the incident angle of the reflected light beam reflected at different times when it enters the receiving end of the speed measurement module is different. The change in the angle is related to the rotation speed of the object to be measured. Therefore, the rotation speed of the object to be measured can be indirectly calculated based on the angle change at different times.

[0194] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0195] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is a better embodiment. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), including a number of instructions for enabling a computer terminal (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in each embodiment of the present invention.

[0196] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are protected by the present invention.

Claims

1. A laser ranging method, characterized in that: Including steps: Obtaining a measurement position, where the measurement position is a first relative position or a second relative position; wherein the step of obtaining the measurement position includes: At a first location, a laser rangefinder is used to emit a laser beam to a first point to be measured, and first laser transceiver data is collected; Calculating a first relative position of the first point to be measured based on the first laser transceiver data; At a second location, the laser rangefinder is used to emit a laser beam to a second point to be measured, and second laser transmission and reception data is collected; Calculating a second relative position of the second point to be measured based on the second laser transceiver data; At least three target distances are calculated based on at least three groups of measurement positions, wherein one group of measurement positions includes a first relative position and a second phase position; the target distance is the distance between the first point to be measured and the second point to be measured; Calculate the difference L2 between any one target distance D1 and at least one other target distance D2; L2 = (D1-D2) / reference distance value; wherein the reference distance value is D1 or D2; When the degree of difference falls within a second threshold range, the target distance D1 is identified as a qualified measurement value; generating a recommended measurement result based on the qualified measurement value; The method adopts the error reduction method to obtain the measurement position, which includes the steps of: S1011, using the laser rangefinder to emit a visible light beam toward the first point to be measured or the second point to be measured; S1012, obtaining a first motion acceleration of the laser rangefinder in a first time period; S1013, generating first jitter data according to the first motion acceleration; S1014: When the first jitter data is less than a first jitter threshold, marking the corresponding first time period as a first-class time period; S1015, determining whether the total duration of the currently continuously generated time period of the type is greater than a first duration threshold, if so, proceeding to S1016; S1016, using the laser rangefinder to transmit a laser beam to the first or second point to be measured during a second time period, and recording corresponding laser emission and reception data; S1017: Calculate at least one of the measurement positions of the first point to be measured or the second point to be measured in the second time period according to the laser emission and reception data, and mark the measurement position with a time tag.

2. A laser ranging method according to claim 1, characterized in that: The steps to calculate target spacing include: Screening out at least one first target point from the plurality of first relative positions, and screening out at least one second target point from the plurality of second relative positions; At least one target distance is calculated based on the at least one first target point and the at least one second target point.

3. A laser ranging method according to claim 2, characterized in that: Before calculating the target distance, the method further includes the steps of: performing a second type of filtering operation on the measurement position; It includes the steps of: Obtaining second motion accelerations recorded by the laser rangefinder at multiple moments in a second time period; generating second jitter data according to the second motion acceleration; When the second jitter data is greater than a second jitter threshold, the measurement position at the corresponding moment is identified as a second-type abnormal point; Calculate the second adjacent time interval of at least two adjacent second-category abnormal points; When the second adjacent time intervals between the plurality of the second-category abnormal points are all less than the preset second time interval, the corresponding plurality of the second-category abnormal points are identified as a second filtering point set; Obtaining a first moment of a leading abnormal point and a second moment of a trailing abnormal point in the second filter point set; A measurement position outside the interval from the first time to the second time is identified as a target point.

4. A laser ranging method according to claim 2, characterized in that: Before calculating the target distance, the method further includes the following steps: calculating a difference between at least two adjacent measurement positions; Identifying at least one of the measurement locations where the difference is greater than a preset first threshold as a type of abnormal point; Obtaining the first adjacent time interval of at least two adjacent abnormal points of the same type; When the first adjacent time intervals between the plurality of abnormal points of the first type are all less than a preset first time interval, the corresponding plurality of abnormal points of the first type are identified as a first filtering point set; Obtaining the third moment of the first abnormal point and the fourth moment of the last abnormal point in the first filter point set; The measured positions outside the interval from the third time to the fourth time are identified as target points.

5. A laser ranging method according to claim 3 or 4, characterized in that: Before calculating the target distance, the method further includes the following steps: Obtaining a target curve generated by the target point and the corresponding time; Smoothing the target curve to obtain a new target curve; Calculate position feature values ​​of multiple points in the new target curve, and use the position feature values ​​as the first relative position or the second relative position, wherein the position feature value is an average value, a mode, or a median of the positions of the multiple points.

6. A laser ranging method according to claim 5, characterized in that: The smoothing process includes one or more of the following: Moving average method, Gaussian filter, median filter, Kalman filter.

7. A laser ranging method according to claim 1, characterized in that: Also includes: Acquire a first distance value and a second distance value generated by laser emission and reception data, wherein the first distance value is the distance between the first point to be measured and the first location, and the second distance value is the distance between the second point to be measured and the second location; Calculate the difference L1 between the first distance value and the second distance value. The calculation rule of the difference L1 is: L1=(first distance value-second distance value) / reference distance value; wherein the reference distance value is the first distance value or the second distance value; When the difference level L1 falls within a first threshold range, a first prompt signal is issued, where the first prompt signal is used to remind the user to pay attention to whether the laser emission path of the laser rangefinder is blocked.

8. A laser ranging system, characterized in that: include: A measuring module, configured to obtain a measurement position, where the measurement position is a first relative position or a second relative position; The measurement module includes: The measurement submodule is configured to use a laser rangefinder to emit a laser beam to a first point to be measured at a first location and collect first laser transceiver data; and use the laser rangefinder to emit a laser beam to a second point to be measured at a second location and collect second laser transceiver data; a first calculation submodule, configured to calculate a first relative position of the first point to be measured based on the first laser transceiver data; and to calculate a second relative position of the second point to be measured based on the second laser transceiver data; A second calculation submodule is configured to calculate at least three target distances based on at least three groups of measurement positions, wherein one group of measurement positions includes a first relative position and a second phase position; the target distance is the distance between the first point to be measured and the second point to be measured; A difference evaluation submodule is configured to calculate a difference L2 between any one target distance D1 and at least one other target distance D2; L2 = (D1-D2) / reference distance value; wherein the reference distance value is D1 or D2; a qualified identification module, configured to identify the target distance D1 as a qualified measurement value when the difference degree falls within a second threshold range; A recommendation output module is used to generate a recommended measurement result based on the qualified measurement value; wherein the measurement module is used to use the laser rangefinder to emit a visible light beam to the first point to be measured or the second point to be measured; obtain a first motion acceleration of the laser rangefinder in a first time period; generate first jitter data based on the first motion acceleration; when the first jitter data is less than a first jitter threshold, mark the corresponding first time period as a type of time period; determine whether the total duration of the type of time period currently generated continuously is greater than a first duration threshold, and if so, use the laser rangefinder to emit a laser beam to the first point to be measured or the second point to be measured in a second time period, and record the corresponding laser emission and reception data; calculate at least one measurement position of the first point to be measured or the second point to be measured in the second time period based on the laser emission and reception data, and the measurement position is marked with a time label.

9. A laser ranging system according to claim 8, characterized in that: Also includes: The rotation speed measurement module is used to emit a light source to the surface of the object to be measured. When the object to be measured rotates, the reflective sheet of the object to be measured will reflect the corresponding reflected light, and the rotation speed of the object to be measured is calculated based on the received reflected light.

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