Field phenotype acquisition crawler capable of automatic focusing and automatic focusing method

Abstract

The application aims to provide a field phenotype acquisition crawler capable of automatic focusing and an automatic focusing method, and relates to the technical field of crop field phenotype acquisition. The crawler comprises a crawler walking mechanism, a lifting field phenotype acquisition mechanism, a piezoelectric ultrasonic sensor device and a control system. The piezoelectric ultrasonic sensor device is used to acquire the real-time distance between the lifting field phenotype acquisition mechanism and crops. The control system is used to control the operation of the crawler walking mechanism according to a preset route, and adjust the lifting of the lifting field phenotype acquisition mechanism according to the real-time distance and the calibration distance between the lifting field phenotype acquisition mechanism and crops. The lifting field phenotype acquisition mechanism is arranged to keep the distance between the push-scan hyperspectral camera in the lifting field phenotype acquisition mechanism and crops at the calibration distance during the driving of the field phenotype acquisition crawler, so that automatic focusing can be performed during field phenotype acquisition, and the quality of hyperspectral images is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of crop field phenotype acquisition, in particular to a field phenotype acquisition tracked vehicle capable of automatic focusing and an automatic focusing method. BACKGROUND

[0002] In the process of field phenotype research of Chinese cabbage, a hyperspectral camera is needed to collect the phenotype of Chinese cabbage. In order to save the work burden of the staff, a tracked vehicle can be used to carry a push-scan type hyperspectral camera to move along a prescribed route in the field and collect hyperspectral image information of Chinese cabbage during the movement.

[0003] The tracked vehicle has good climbing ability and is suitable for field work. Meanwhile, the tracked vehicle can protect the soil from forming plough pan by means of the track. However, the tracked vehicle is relatively heavy, has poor flexibility and mobility, and runs slowly, which leads to a large position offset and a long offset time of the push-scan type hyperspectral camera carried on the tracked vehicle in the vertical direction of the ground in the uneven field, and thus makes it difficult for the hyperspectral camera to automatically focus during the forward push-scan process of the tracked vehicle, thereby affecting the quality of the acquired hyperspectral images. At present, the automatic focusing method for the hyperspectral camera mainly aims at the hyperspectral camera carried on the unmanned aerial vehicle, and there is little research on the automatic focusing method for the hyperspectral camera of the field tracked vehicle. Therefore, there is an urgent need for a field phenotype acquisition tracked vehicle capable of automatic focusing and an automatic focusing method. SUMMARY

[0004] The purpose of the present application is to provide a field phenotype acquisition tracked vehicle capable of automatic focusing and an automatic focusing method, which can automatically focus during field phenotype acquisition to ensure the quality of hyperspectral images.

[0005] To achieve the above purpose, the present application provides the following solutions.

[0006] A field phenotype acquisition tracked vehicle capable of automatic focusing, comprising:

[0007] a tracked walking mechanism, a lifting field phenotype acquisition mechanism, a piezoelectric ultrasonic sensor device and a control system;

[0008] The control system is connected with the tracked walking mechanism, the lifting field phenotype acquisition mechanism and the piezoelectric ultrasonic sensor device respectively;

[0009] The piezoelectric ultrasonic sensor device is used to acquire the real-time distance between the lifting field phenotype acquisition mechanism and the crops;

[0010] The control system is used to control the tracked walking mechanism to run according to a preset route;

[0011] The control system is further configured to adjust the lifting of the lifting field phenotyping mechanism according to the real-time distance and the calibrated distance between the lifting field phenotyping mechanism and the crops.

[0012] The lifting field phenotyping mechanism is configured to acquire hyperspectral images of the crops.

[0013] Optionally, the lifting field phenotyping mechanism comprises:

[0014] a lifting two-axis mechanical arm and a push-broom hyperspectral camera;

[0015] The lifting two-axis mechanical arm is configured to be lifted simultaneously with the push-broom hyperspectral camera and the piezoelectric ultrasonic sensor device.

[0016] Optionally, the lifting two-axis mechanical arm comprises:

[0017] a base, a column and a cantilever;

[0018] The base is parallel to the tracked walking mechanism; the base is connected to the tracked walking mechanism; the column is rotatably arranged on the base; one end of the cantilever is slidably sleeved on the column; the cantilever is perpendicular to the column;

[0019] The other end of the cantilever is configured to carry the piezoelectric ultrasonic sensor device and the push-broom hyperspectral camera.

[0020] Optionally, the lifting two-axis mechanical arm further comprises:

[0021] a first servo motor;

[0022] The first servo motor is mechanically connected to the column;

[0023] The first servo motor is electrically connected to the control system; the control system is configured to control the first servo motor to adjust the angle of the column, so that the cantilever is parallel to the ground.

[0024] Optionally, the lifting two-axis mechanical arm further comprises:

[0025] a second servo motor;

[0026] The second servo motor is mechanically connected to the cantilever;

[0027] The second servo motor is electrically connected to the control system; the control system is further configured to control the second servo motor to adjust the height of the cantilever.

[0028] An automatic focusing method applied to the above-mentioned field phenotyping tracked vehicle with automatic focusing function, the automatic focusing method comprising:

[0029] The piezoelectric ultrasonic sensor device obtains the real-time distance between the lifting field phenotyping mechanism and the crops;

[0030] The control system adjusts the lifting of the lifting field phenotyping mechanism according to the real-time distance and the calibrated distance between the lifting field phenotyping mechanism and the crops.

[0031] The lifting field phenotyping mechanism obtains the hyperspectral image of the crops.

[0032] Optionally, before the piezoelectric ultrasonic sensor device obtains the real-time distance between the lifting field phenotyping mechanism and the crops, the method further comprises:

[0033] The control system controls the operation of the crawler walking mechanism according to the preset route.

[0034] Optionally, the control system adjusts the lifting of the lifting field phenotyping mechanism according to the real-time distance and the calibrated distance between the lifting field phenotyping mechanism and the crops, and the method comprises:

[0035] Determining the difference between the real-time distance and the calibrated distance between the lifting field phenotyping mechanism and the crops.

[0036] Determining the lifting direction of the cantilever according to the positive or negative of the difference.

[0037] Controlling the second servo motor to move the cantilever in the lifting direction with the difference as the moving distance.

[0038] Optionally, before the control system adjusts the lifting of the lifting field phenotyping mechanism according to the real-time distance and the calibrated distance between the lifting field phenotyping mechanism and the crops, the method further comprises:

[0039] The control system controls the first servo motor to adjust the angle of the stand to make the cantilever parallel to the ground.

[0040] According to the specific embodiments of the present application, the following technical effects are provided:

[0041] The application aims to provide an automatic focusing field phenotype acquisition tracked vehicle and an automatic focusing method. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and all other drawings obtained by those skilled in the art without creative labor based on the embodiments in the present application are within the protection scope of the present application.

[0043] Figure 1 FIG. 1 is a structure schematic diagram of the automatic focusing field phenotype acquisition tracked vehicle in the embodiment 1 of the present application.

[0044] Figure 2 FIG. 2 is a flow chart of the automatic focusing method in the embodiment 2 of the present application.

[0045] Brief description of drawings: 1-pushbroom hyperspectral camera; 2-piezoelectric ultrasonic sensor device; 3-lifting two-axis mechanical arm; 301-cantilever; 302-stand; 303-rotary support mechanism; 304-base; 4-servo motor; 5-control system; 6-caterpillar walking mechanism. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0047] The present application aims to provide an automatic focusing field phenotyping tracked vehicle and an automatic focusing method, which can automatically focus when field phenotyping to ensure high spectral image quality.

[0048] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below in combination with the drawings and specific embodiments.

[0049] Embodiment 1

[0050] The present embodiment provides an automatic focusing field phenotyping tracked vehicle, comprising:

[0051] The tracked walking mechanism 6, the lifting field phenotyping mechanism 3, the piezoelectric ultrasonic sensor device 2 and the control system 5;

[0052] The control system is connected with the tracked walking mechanism, the lifting field phenotyping mechanism and the piezoelectric ultrasonic sensor device respectively;

[0053] The piezoelectric ultrasonic sensor device is used to obtain the real-time distance between the lifting field phenotyping mechanism and the crops;

[0054] The control system is used to control the tracked walking mechanism to run according to the preset route;

[0055] The control system is also used to adjust the lifting of the lifting field phenotyping mechanism according to the real-time distance and the calibration distance between the lifting field phenotyping mechanism and the crops;

[0056] The lifting field phenotyping mechanism is used to obtain the hyperspectral image of the crops. The lifting field phenotyping mechanism comprises a lifting two-axis mechanical arm and a push-broom hyperspectral camera 1. The lifting two-axis mechanical arm is used to lift together with the push-broom hyperspectral camera and the piezoelectric ultrasonic sensor device.

[0057] The lifting two-axis mechanical arm comprises a base 304, a rotary support mechanism 303 (including a column 302 and a cantilever 301), and a servo motor 4 (including a first servo motor and a second servo motor). The base is parallel to the tracked walking mechanism. The base is connected with the tracked walking mechanism. The column is rotatably arranged on the base. One end of the cantilever is slidably sleeved on the column. The cantilever is perpendicular to the column. The other end of the cantilever is used to carry the piezoelectric ultrasonic sensor device and the push-broom hyperspectral camera.

[0058] The first servo motor is mechanically connected with the column, and the first servo motor is electrically connected with the control system; the control system is used for controlling the first servo motor to adjust the angle of the column, so that the cantilever is parallel to the ground, and the piezoelectric ultrasonic sensor device is used to obtain the vertical distance between the lifting field phenotype acquisition mechanism and the crops. The second servo motor is mechanically connected with the cantilever, and the second servo motor is electrically connected with the control system; the control system is also used for controlling the second servo motor to adjust the height of the cantilever.

[0059] In the following, the present embodiment is specifically described by taking the field phenotype acquisition of Chinese cabbage as an example:

[0060] As Figure 1 , the field phenotype acquisition crawler of Chinese cabbage comprises a crawler-type walking mechanism, a lifting two-axis mechanical arm, a piezoelectric ultrasonic sensor device, a push-broom hyperspectral camera, a control system and servo motors. The lifting two-axis mechanical arm is installed on the crawler-type walking mechanism, and the mechanical arm is composed of a base, a column part and a cantilever part, wherein the base and the column part are a rotary support mechanism, and the servo motors can drive the column to rotate and the cantilever to rise and fall; the push-broom hyperspectral camera is connected with the terminal end of the cantilever of the lifting two-axis mechanical arm, and the camera is in an upright state with the lens facing the ground; a mounting hole is arranged near the terminal end of the cantilever of the lifting two-axis mechanical arm, and the piezoelectric ultrasonic sensor device is mounted thereon, so that the ultrasonic sensor faces the ground, and the wire harness thereof is connected with the control system. Figure 1 F is the focal point of the focusing lens of the hyperspectral camera.

[0061] As Figure 2 , before the field phenotype acquisition crawler of Chinese cabbage starts to work, it is placed at the starting point of the planned path of the crawler, and the hyperspectral camera is aligned with the midpoint of the first row of Chinese cabbage. The operator manually focuses the hyperspectral camera and acquires a hyperspectral image to ensure clear imaging.

[0062] Subsequently, the crawler is started to work along the planned path in the field. At the same time when the crawler starts to work, the control system applies a pulse signal to the two poles of the piezoelectric ultrasonic sensor, so that the piezoelectric wafer resonates to generate ultrasonic waves perpendicular to the ground. When the ultrasonic waves encounter Chinese cabbage, they are reflected, the piezoelectric wafer receives the ultrasonic waves again and converts them into electrical signals to be transmitted to the control system, and the initial distance h0 between Chinese cabbage and the piezoelectric ultrasonic sensor when the manually focused hyperspectral camera is acquired is calibrated. According to the distance measuring principle of the piezoelectric ultrasonic sensor, the distance between Chinese cabbage and the sensor is determined by the propagation speed of ultrasonic waves in air and the time used for the ultrasonic waves emitted by the sensor to encounter Chinese cabbage and return to be received. Therefore, it can be known that the initial distance h0 between Chinese cabbage and the piezoelectric ultrasonic sensor and the initial distance u0 between Chinese cabbage and the focusing lens of the hyperspectral camera are as shown in equations (1) and (2). And according to the Gaussian imaging distribution formula, the theoretical value of u0 is u as shown in equation (3).

[0063] With the continuous advance of the tracked vehicle, the piezoelectric ultrasonic sensor continuously obtains the real-time distance h1 between the Chinese cabbage and the piezoelectric ultrasonic sensor and transmits an electrical signal to the control system, and the control system makes the cantilever part of the lifting two-axis mechanical arm move upward or downward by a distance h2 according to the difference between the real-time distance and the initial distance, as shown in formula (4), so that the distance between the Chinese cabbage and the ultrasonic sensor is always kept at the initial distance h0, thereby realizing automatic focusing of the hyperspectral camera and ensuring the imaging quality of the hyperspectral image during the operation of the tracked vehicle.

[0064] h0=C×T0 (1)

[0065] u0=h0-a=C×T0-a (2)

[0066] In the formula, h0 is the initial distance between the Chinese cabbage and the piezoelectric ultrasonic sensor, in mm; T0 is the time used for the initial ultrasonic wave to encounter the Chinese cabbage and return to the ultrasonic sensor, in m / s; u0 is the initial distance between the Chinese cabbage and the focusing lens of the hyperspectral camera, in mm; a is the distance between the piezoelectric ultrasonic sensor and the focusing lens of the hyperspectral camera, in mm; and C is the propagation speed of ultrasonic waves in air, in m / s.

[0067]

[0068] In the formula, u is the theoretical distance between the Chinese cabbage and the focusing lens of the hyperspectral camera, in mm; v is the theoretical distance between the focusing lens of the hyperspectral camera and the hyperspectral imaging, in mm; and f is the focal length, in mm.

[0069] h2=h1-h0 (4)

[0070] In the formula, h2 is the distance by which the cantilever part of the lifting two-axis mechanical arm moves upward or downward, in mm; and h1 is the real-time distance between the Chinese cabbage and the piezoelectric ultrasonic sensor, in mm.

[0071] Embodiment 2

[0072] The embodiment provides an automatic focusing method, and the automatic focusing method is applied to the tracked vehicle for field phenotyping with automatic focusing in embodiment 1.

[0073] The piezoelectric ultrasonic sensor device obtains the real-time distance between the lifting field phenotyping mechanism and the crop;

[0074] The control system adjusts the lifting of the lifting field phenotyping mechanism according to the real-time distance and the calibration distance between the lifting field phenotyping mechanism and the crop.

[0075] The lifting field phenotyping mechanism obtains the hyperspectral image of the crop.

[0076] Before the piezoelectric ultrasonic sensor device obtains the real-time distance between the lifting field phenotyping acquisition mechanism and the crops, the method further comprises:

[0077] The control system controls the caterpillar walking mechanism to run according to the preset route.

[0078] The control system adjusts the lifting of the lifting field phenotyping acquisition mechanism according to the real-time distance and the calibration distance, and the method comprises:

[0079] Determining the difference between the real-time distance and the calibration distance of the lifting field phenotyping acquisition mechanism and the crops;

[0080] Determining the lifting direction of the cantilever according to the positive and negative of the difference;

[0081] Controlling the second servo motor to move the cantilever in the lifting direction with the difference as the moving distance.

[0082] The automatic focusing method provided in the embodiment further comprises:

[0083] The control system controls the first servo motor to adjust the angle of the stand to make the cantilever parallel to the ground.

[0084] The embodiments in the specification are described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts of each embodiment can be referred to each other. For the system disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple, and the related parts can be referred to the method part.

[0085] The principles and implementation manners of the present application are described by using specific examples in the present application. The above embodiment is only used to help understand the method of the present application and its core idea. For those skilled in the art, according to the idea of the present application, the specific implementation manner and application range can be changed. In conclusion, the content of the specification should not be understood as a limitation of the present application.

Claims

1. An auto-focusable field phenotyping tracked vehicle, characterized in that, The application relates to a track-type walking mechanism, a lifting field phenotype acquisition mechanism, a piezoelectric ultrasonic sensor device and a control system. The control system is connected with the track-type walking mechanism, the lifting field phenotype acquisition mechanism and the piezoelectric ultrasonic sensor device respectively. The lifting two-axis mechanical arm in the lifting field phenotype acquisition mechanism comprises a base, a stand and a cantilever; the base is parallel to the track-type walking mechanism; the base is connected with the track-type walking mechanism; the stand is rotatably arranged on the base; one end of the cantilever is slidably sleeved on the stand; the cantilever is perpendicular to the stand; the lifting two-axis mechanical arm further comprises a first servo motor; the first servo motor is mechanically connected with the stand; the first servo motor is electrically connected with the control system; the control system is used for controlling the first servo motor to adjust the angle of the stand, so that the cantilever is parallel to the ground. The piezoelectric ultrasonic sensor device is used for acquiring the real-time distance between the lifting field phenotype acquisition mechanism and crops. The control system is used for controlling the track-type walking mechanism to run according to a preset route. The control system is further used for adjusting the lifting of the lifting field phenotype acquisition mechanism according to the real-time distance and the calibration distance between the lifting field phenotype acquisition mechanism and crops; and the lifting of the lifting field phenotype acquisition mechanism is controlled according to the following formula: The lifting field phenotype acquisition mechanism is used for acquiring the hyperspectral image of crops. ； ； ； ； wherein, is the initial distance of the cabbage from the piezoelectric ultrasonic sensor, is the speed of ultrasonic wave in air; is the time used between the initial ultrasonic wave emission and the return of the ultrasonic wave from the cabbage; is the initial distance of the cabbage from the hyperspectral camera focusing lens; is the distance of the piezoelectric ultrasonic sensor from the hyperspectral camera focusing lens; is the theoretical distance of the cabbage from the hyperspectral camera focusing lens; is the theoretical distance of the hyperspectral camera focusing lens from the hyperspectral imaging; is the focal length, is the distance of the upward or downward movement of the cantilevered portion of the lifting two-axis mechanical arm; is the real-time distance of the cabbage from the piezoelectric ultrasonic sensor; The lifting field phenotype acquisition mechanism comprises:

2. The self-focusing field phenotyping tracked vehicle of claim 1, wherein, A lifting two-axis mechanical arm and a push-broom hyperspectral camera. The lifting two-axis mechanical arm is used for lifting together with the push-broom hyperspectral camera and the piezoelectric ultrasonic sensor device. The other end of the cantilever is used for carrying the piezoelectric ultrasonic sensor device and the push-broom hyperspectral camera.

3. The self-focusing field phenotyping tracked vehicle of claim 2, wherein, The lifting two-axis mechanical arm further comprises:

4. The self-focusing field phenotyping tracked vehicle of claim 1, wherein, A second servo motor; The second servo motor is mechanically connected with the cantilever; The second servo motor is electrically connected with the control system; and the control system is further used for controlling the second servo motor to adjust the height of the cantilever. The automatic focusing method is applied to the field phenotype acquisition track vehicle with automatic focusing as claimed in any one of claims 1-4, and the automatic focusing method comprises:

5. An autofocusing method characterized by, The piezoelectric ultrasonic sensor device acquires the real-time distance between the lifting field phenotype acquisition mechanism and crops; The control system adjusts the lifting of the lifting field phenotype acquisition mechanism according to the real-time distance and the calibration distance between the lifting field phenotype acquisition mechanism and crops; and the lifting of the lifting field phenotype acquisition mechanism is controlled according to the following formula: The lifting field phenotype acquisition mechanism acquires the hyperspectral image of crops; ； ； ； ； wherein, is the initial distance between the cabbage and the piezoelectric ultrasonic sensor, is the propagation speed of the ultrasonic wave in the air; is the time used between the initial ultrasonic wave emission and the return of the ultrasonic wave after encountering the cabbage; is the initial distance between the cabbage and the focusing lens of the hyperspectral camera; is the distance between the piezoelectric ultrasonic sensor and the focusing lens of the hyperspectral camera; is the theoretical distance between the cabbage and the focusing lens of the hyperspectral camera; is the theoretical distance between the focusing lens of the hyperspectral camera and the hyperspectral imaging; is the focal length, is the distance of the upward or downward movement of the cantilevered portion of the lifting two-axis mechanical arm; is the real-time distance between the cabbage and the piezoelectric ultrasonic sensor; Before the control system adjusts the lifting of the lifting field phenotype acquisition mechanism according to the real-time distance and the calibration distance between the lifting field phenotype acquisition mechanism and crops, the control system controls the first servo motor to adjust the angle of the stand, so that the cantilever is parallel to the ground. Before the piezoelectric ultrasonic sensor device acquires the real-time distance between the lifting field phenotype acquisition mechanism and crops, the following steps are further included:

6. The method of claim 5, wherein, ​ The control system controls the operation of the crawler walking mechanism according to a preset route.

7. The method of claim 5, wherein, The control system adjusts the lifting of the lifting field phenotyping mechanism according to the real-time distance and the calibrated distance between the lifting field phenotyping mechanism and the crops, and the control system comprises: determining the difference between the real-time distance and the calibrated distance between the lifting field phenotyping mechanism and the crops; determining the lifting direction of the cantilever according to the positive and negative of the difference; controlling the second servo motor to move the cantilever in the lifting direction with the difference as the moving distance.

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