A dual-servo scanning laser radar and a volume measurement method based on the radar

Abstract

The present disclosure relates to a laser radar, and in particular to a dual-servo scanning laser radar, including a laser radar, a primary servo, a secondary servo, and a controller. The laser radar is used for data acquisition; the primary servo is connected to the secondary servo, and is used to drive the secondary servo to swing step by step, and its swing direction is set to the Y axis; the secondary servo is used to drive the laser radar to step, and its step swing direction is set to the X axis, and the X and Y axes are orthogonal; the controller is used to control the work of the primary and secondary servos, receive the data of the laser radar and process it to obtain the result. The embodiment of the present disclosure adopts dual servos to perform step swing, drive the laser radar to scan the object point by point, obtain the data of the object, and then process the data to obtain the volume of the object. This system not only solves the problem that the single-point laser radar cannot accurately measure in the object volume measurement scheme, but also has the advantage of low cost.

Description

Technical Field

[0001] The present invention discloses a laser radar, and in particular, relates to a dual-servo scanning laser radar and a volume measurement method based on the radar. Background Art

[0002] Existing volume detection technology often obtains the density and weight of the object and uses the formula M = pV to calculate the volume. The density of the object is measured by a special device, a density meter, and the weight of the object is obtained by a weighing sensor. When the size or weight of the object cannot be obtained directly, it is necessary to use a lidar to detect the volume of the object. There are two types of lidar used in existing detection methods: single-point lidar and array lidar. Single-point lidar estimates the volume of the entire object based on the distance measurement of a point. This method is suitable for regular objects, but the error for irregular objects is very large. Array lidar can accurately obtain information such as the appearance and contour of the object, and calculate the volume relatively accurately, but the construction cost is high. The use of array lidar sensors to process noise requires high computing power and consumes a lot of power, which cannot meet the use of lidar under low power consumption conditions. Summary of the invention

[0003] The embodiment of the present disclosure is to propose a laser radar to solve the problem that the existing laser radar cannot simultaneously achieve accurate volume measurement and low cost. To achieve this purpose, the present disclosure adopts the following technical solutions:

[0004] On the one hand, a dual-servo scanning laser radar includes a laser radar, a first-level steering gear, a second-level steering gear, and a controller.

[0005] The laser radar is used for distance measurement and data collection;

[0006] The first-level steering gear is connected to the second-level steering gear, and is used to drive the second-level steering gear to swing step by step, change the position and angle of the second-level steering gear, and then change the position and detection direction of the laser radar connected to the second-level steering gear, and its swing direction is set to the Y axis;

[0007] The secondary servo is connected to the laser radar and the primary servo, and is used to drive the laser radar to step. The secondary servo steps and swings to change the position and scanning angle of the laser radar. The stepping and swinging direction is set to the X axis. The X and Y axes are orthogonal to each other, and the directions orthogonal to the X and Y axes are set to be the Z axis.

[0008] The controller is connected with the laser radar, the first-level steering gear and the second-level steering gear, and is used to control the operation of the first-level and second-level steering gears, receive the data of the laser radar and process and obtain the results.

[0009] In a possible implementation, the maximum swing angle of the first-stage servo is 100-180°, the step swing angle is 0.5-2° each time, the rotation speed is 0.5-2° / s, and the step delay is 500ms-1s.

[0010] In a possible implementation, the first-stage servo has a maximum swing angle of 120-140°, a step swing angle of 0.6-1° each time, a rotation speed of 1-1.5° / s, and a step delay of 600-800ms.

[0011] In a possible implementation, the secondary servo has a maximum swing angle of 100-180°, a step swing angle of 0.5-2° each time, a rotation speed of 100-150° / s, and a step delay of 10-50ms.

[0012] In a possible implementation, the secondary servo has a maximum swing angle of 120-140°, a step swing angle of 0.6-1° each time, a rotation speed of 120-130° / s, and a step delay of 20-40ms.

[0013] In a possible implementation, the laser radar is a single-point laser radar with a collection period of 1-50ms.

[0014] In a possible implementation, the step delay of the first-level servo is greater than the step delay of the second-level servo, and the step delay of the second-level servo is greater than the acquisition period of the laser radar.

[0015] In a possible implementation, the controller includes a data filtering unit and a sliding integration unit. The data filtering unit is used to delete excessively large or small distance values ​​according to a distance threshold; the sliding integration unit is used to integrate the laser radar collected data to form the volume of the entire object.

[0016] On the other hand, a volume measurement method based on dual-servo scanning laser radar, in which the controller controls the second-level servo to step and swing, drives the laser radar to rotate to change the measurement angle for scanning, and obtains a set of X, Y, and Z data of object points, and then controls the first-level servo to rotate, drives the second-level servo and the laser radar to the next position for scanning, and obtains another set of X, Y, and Z data of object points. The controller counts the X, Y, and Z data of all object points and calculates the volume of the detected object.

[0017] In a possible implementation, the volume measurement method based on dual-servo scanning laser radar includes the following steps:

[0018] A. Perform the secondary servo zeroing operation;

[0019] B. The controller controls the secondary servo to swing step by step, driving the laser radar to rotate and change the measurement angle for scanning, performing the first scan and collecting a set of X, Y, and Z data of object points;

[0020] C. Control the first-stage servo to rotate, driving the second-stage servo and laser radar to the next position;

[0021] D. The secondary servo performs scanning to obtain the X, Y, and Z data of another set of object points;

[0022] E. The controller filters the data collected twice adjacently and performs smooth integration on the data;

[0023] F. Continue to run the BE steps, integrate and accumulate the objects and output them.

[0024] The disclosed embodiment adopts dual servos to perform stepping swings, driving the laser radar to scan the object point by point, obtain the data of the object, and then process the data to obtain the volume of the object. This system not only solves the problem that the single-point laser radar cannot accurately measure in the object volume measurement solution, but also has the advantage of low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the connection between the servo and the laser radar disclosed in the present invention.

[0026] Figure 2 It is a schematic diagram of the overall framework of the present invention.

[0027] In the figure: 1. LiDAR; 2. First-stage servo; 3. Second-stage servo; 4. Controller. DETAILED DESCRIPTION

[0028] The technical solution of the present disclosure is further explained below with reference to the accompanying drawings and through specific implementation methods.

[0029] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure may be combined with each other. The present disclosure will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0030] In order to enable those skilled in the art to better understand the scheme of the present disclosure, the technical scheme in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present disclosure.

[0031] It should be noted that the terms "first", "second", etc. in the specification and claims of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so as to describe the embodiments of the present disclosure described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, device, product or equipment that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0032] Embodiments of the present disclosure

[0033] like Figure 1 As shown, a dual-servo scanning laser radar includes a laser radar 1, a first-stage servo 2, a second-stage servo 3, and a controller 4.

[0034] The laser radar 1 is used for distance measurement and data collection;

[0035] The first-level steering gear 2 is connected to the second-level steering gear 3, and is used to drive the second-level steering gear 3 to swing step by step, change the position and angle of the second-level steering gear 3, and then change the position and detection direction of the laser radar 1 connected to the second-level steering gear 3, and its swing direction is set to the Y axis;

[0036] The secondary steering engine 3 is connected to the laser radar 1 and the primary steering engine 2, and is used to drive the laser radar 1 to step. The secondary steering engine 3 swings in steps to change the position and scanning angle of the laser radar 1. The stepping swing direction is set to the X axis. The X and Y axes are orthogonal to each other, and the directions orthogonal to the X and Y axes are set to be the Z axis.

[0037] like Figure 2 As shown, the controller 4 is connected to the laser radar 1, the first-level steering gear 2, and the second-level steering gear 3 for controlling the operation of the first-level and second-level steering gears, receiving data from the laser radar 1 and processing the data to obtain the results.

[0038] The disclosed embodiment adopts dual servos to drive the laser radar 1 to move stepwise on the X and Y axes, scans the object point by point, obtains the data of the object, and then calculates and processes to obtain the volume of the object. This system not only solves the problem that the single-point laser radar cannot measure relatively accurately in the object volume measurement scheme, improves the accuracy of volume measurement, but also has the advantage of low cost.

[0039] The maximum swing angle of the first-level steering engine 2 is 100-180°, the step swing angle is 0.5-2° each time, the rotation speed is 0.5-2° / s, and the step delay is 500ms-1s.

[0040] The maximum swing angle of the first-stage steering engine 2 is 120-140°, the step swing angle is 0.6-1° each time, the rotation speed is 1-1.5° / s, and the step delay is 600-800ms.

[0041] The first-stage servo 2 drives the second-stage servo 3 and the laser radar 1 to swing in steps. The maximum swing angle determines the angle or distance that the second-stage servo 3 and the laser radar 1 can operate. The maximum swing angle of the first-stage servo 2 divided by the swing angle of each step is equal to the number of steps. Generally speaking, the more steps the first-stage servo 2 takes, the more times the laser radar 1 scans, and the more points are scanned. Therefore, the maximum swing angle of the first-stage servo 2 is 100-180°, and the swing angle of each step is 0.5-2°, that is, during the maximum swing of the first-stage servo 2, the number of steps is between 50-360 times. Furthermore, the maximum swing angle of the first-stage servo 2 is 120-140°, and the swing angle of each step is 0.6-1°, which can work more stably.

[0042] At the same time, each operation must take into account the running time of the secondary servo 3. The next operation can only be performed after the secondary servo 3 has finished running. The step delay of the primary servo 2 is set to 500ms-1s, which can meet the running time requirements. To further improve the accuracy, the step delay can be set to 600-800ms.

[0043] The maximum swing angle of the secondary steering gear is 100-180°, the step swing angle is 0.5-2° each time, the rotation speed is 100-150° / s, and the step delay is 10-50ms.

[0044] The maximum swing angle of the secondary steering gear is 120-140°, the step swing angle is 0.6-1° each time, the rotation speed is 120-130° / s, and the step delay is 20-40ms.

[0045] The secondary servo 3 is directly connected to the laser radar 1, so the maximum swing angle of the secondary servo 3 determines the scanning angle or distance of the laser radar 1. The maximum swing angle of the secondary servo 3 divided by the swing angle of each step is equal to the number of steps. Generally speaking, the more steps the secondary servo 3 has, the more times the laser radar 1 scans, and the more points are scanned. Therefore, the maximum swing angle of the secondary servo 3 is 100-180°, and the swing angle of each step is 0.5-2°. During the maximum swing of the secondary servo 3, the number of steps is between 50-360 times. Furthermore, the maximum swing angle of the first-stage servo 2 is 120-140°, and the swing angle of each step is 0.6-1°, which can work more stably.

[0046] Check whether the laser radar 1 data has been collected. If not, many points will be repeated. Only when the collection is completed can the next step be performed. Therefore, the step delay of the secondary servo 3 here should be greater than the laser radar 1 data collection cycle.

[0047] The laser radar 1 is a single-point laser radar with a collection period of 1-50ms.

[0048] The step delay of the first-level steering gear 2 is greater than the step delay of the second-level steering gear 3 , and the step delay of the second-level steering gear 3 is greater than the acquisition period of the laser radar 1 .

[0049] The controller 4 includes a data filtering unit and a sliding integration unit. The data filtering unit is used to delete excessively large or small distance values ​​according to a distance threshold; the sliding integration unit is used to integrate the laser radar collected data to form the volume of the entire object.

[0050] The distance value that is too large or too small is defined according to the maximum range of the laser radar 1 and the installation method. The default setting is that the maximum detection range of the laser radar 1 is 40 meters. Points exceeding 40 meters are invalid points (outliers) and are removed; the maximum height is set to 8 meters, and the calculated height is greater than 8 meters. Points are invalid points (outliers) and are removed.

[0051] On the other hand, the controller 4 controls the stepping swing of the secondary servo 3, drives the laser radar 1 to rotate to change the measuring angle for scanning, and obtains a set of X, Y, and Z data of object points. Then the controller 4 controls the rotation of the primary servo 2, drives the secondary servo 3 and the laser radar 1 to the next position for scanning, and obtains another set of X, Y, and Z data of object points. The controller 4 counts the X, Y, and Z data of all object points and calculates the volume of the detected object.

[0052] The method for calculating the volume of an object based on a dual-servo scanning laser radar comprises the following steps:

[0053] A. Return the secondary servo 3 to zero position;

[0054] B. The controller 4 controls the secondary servo 3 to swing in steps, driving the laser radar to rotate and change the measurement angle to scan, perform the first scan, and collect a set of X, Y, and Z data of the object point;

[0055] C. Control the first-level servo 2 to rotate, driving the second-level servo 3 and laser radar 1 to the next position;

[0056] D. The secondary servo 3 scans and obtains the X, Y, and Z data of another set of object points;

[0057] E. The controller 4 filters the data collected twice adjacently and performs smoothing integration on the data;

[0058] F. Continue to run the BE steps, integrate and accumulate the objects and output them.

[0059] Here, an example of smooth integration is given. In the case where the first-level servo 2 scans 120° and the second-level servo 3 also scans 120°, after the first-level servo 2 steps 1°, the second-level servo 3 scans 120°, and the X, Y, and Z values ​​of 120 points are obtained, namely points 1-120. After that, the first-level servo 2 scans 1° again, and the second-level servo 3 scans 120°, and the X, Y, and Z values ​​of 120 points are obtained, namely points 121-240. Smooth integration means that the four points 1, 2, 239, and 240 form a quadrilateral in the XY plane. According to the X, Y, and Z values, the volume of the cube can be calculated; similarly, the next quadrilateral is smoothed to be composed of points 2, 3, 238, and 239. The volume of this cube can be calculated based on the average value of the heights of these four points. All points are calculated in turn to obtain the volume of 119 cubes, and all are added up to get the volume of the scanned 2 rows (degrees). After performing the 120° scan in sequence, the entire volume covering the entire area of ​​120°*120° is obtained.

[0060] The technical principles of the present disclosure are described above in conjunction with specific embodiments. These descriptions are only for explaining the principles of the present disclosure and cannot be interpreted as limiting the protection scope of the present disclosure in any way. Based on the explanations herein, those skilled in the art can think of other specific implementation methods of the present disclosure without creative work, and these methods will fall within the protection scope of the present disclosure.

Claims

1. A dual-servo scanning laser radar, characterized in that: Including laser radar, first-level servo, second-level servo, controller, The laser radar is used for distance measurement and data collection, and the laser radar is a single-point laser radar; The first-level steering gear is connected to the second-level steering gear, and is used to drive the second-level steering gear to swing step by step, change the position and angle of the second-level steering gear, and then change the position and detection direction of the laser radar connected to the second-level steering gear, and its swing direction is set to the Y axis; The secondary servo is connected to the laser radar and the primary servo, and is used to drive the laser radar to step. The secondary servo steps and swings to change the position and scanning angle of the laser radar. The stepping and swinging direction is set to the X axis. The X and Y axes are orthogonal to each other, and the directions orthogonal to the X and Y axes are set to be the Z axis. The controller is connected to the laser radar, the first-level steering gear, and the second-level steering gear, and is used to control the operation of the first-level and second-level steering gears, receive the data of the laser radar, and process and obtain the results; The controller includes a data filtering unit and a sliding integration unit, wherein the data filtering unit is used to delete excessively large or small distance values ​​according to a distance threshold; The associated sliding integration unit is used to integrate the lidar acquisition data to form the volume of the entire object.

2. The dual-servo scanning laser radar according to claim 1, characterized in that: The maximum swing angle of the first-level steering gear is 100-180°, the step swing angle is 0.5-2° each time, the rotation speed is 0.5-2° / s, and the step delay is 500ms-1s.

3. The dual-servo scanning laser radar according to claim 2, characterized in that: The maximum swing angle of the first-stage servo is 120-140°, the step swing angle is 0.6-1° each time, the rotation speed is 1-1.5° / s, and the step delay is 600-800ms.

4. The dual-servo scanning laser radar according to claim 3, characterized in that: The maximum swing angle of the secondary steering gear is 100-180°, the step swing angle is 0.5-2° each time, the rotation speed is 100-150° / s, and the step delay is 10-50ms.

5. The dual-servo scanning laser radar according to claim 4, characterized in that: The maximum swing angle of the secondary steering gear is 120-140°, the step swing angle is 0.6-1° each time, the rotation speed is 120-130° / s, and the step delay is 20-40ms.

6. The dual-servo scanning laser radar according to claim 5, characterized in that: The acquisition period of the laser radar is 1-50ms.

7. The dual-servo scanning laser radar according to claim 6, characterized in that: The step delay of the first-level steering gear is greater than the step delay of the second-level steering gear, and the step delay of the second-level steering gear is greater than the acquisition period of the laser radar.

8. A volume measurement method based on dual-servo scanning laser radar, characterized in that: The controller controls the second-level servo to step and swing, driving the single-point laser radar to rotate and change the measurement angle for scanning, and obtains a set of X, Y, and Z data of the object point. Then the controller controls the first-level servo to rotate, driving the second-level servo and laser radar to the next position for scanning, and obtains another set of X, Y, and Z data of the object point. The controller counts the X, Y, and Z data of all object points and calculates the volume of the detected object. A. Perform the secondary servo zeroing operation; B. The controller controls the secondary servo to swing step by step, driving the laser radar to rotate and change the measurement angle for scanning, performing the first scan and collecting a set of X, Y, and Z data of object points; C. Control the first-stage servo to rotate, driving the second-stage servo and laser radar to the next position; D. The secondary servo performs scanning to obtain the X, Y, and Z data of another set of object points; E. The controller filters the data collected twice adjacently and performs smooth integration on the data; F. Continue to run the BE steps, accumulate the integral of the object and output it.

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