A device and method for detecting local terrain

Abstract

The present invention discloses a device and method for detecting local terrain. The position information of a sphere in a geodetic coordinate system can be determined by a spherical measurement incremental encoder and a grating ruler of a spherical mechanism. The linear accelerations on three axes collected by an inertial measurement unit are projected to a geodetic coordinate system. The position information of the inertial measurement unit in the geodetic coordinate system is determined by two integral calculations, and the position information of the ground contact point of the sphere is further determined. The position information of three omnidirectional wheels in a geodetic coordinate system can be determined by a walking measurement incremental encoder of a walking mechanism, and the position information of the ground contact point of the sphere is further determined by the rotational transformation relationship between the mechanical structure of the device and the system coordinate system. The discrete position information obtained above is fused through Kalman filtering, and the gradient derivative is performed on the fused data to construct a terrain model. The present invention can effectively and accurately detect unknown terrain.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent robots, and in particular to a device and method for detecting local terrain. Background Art

[0002] At present, the commonly used methods for detecting local terrain are laser radar scanning and graphic image recognition. However, these two methods of detecting local terrain have some shortcomings: the laser radar scanning method is not only affected by terrain and bad weather and cannot be detected, but also the laser radar products used are expensive, which limits the promotion of laser radar scanning in the mass market. The graphic image recognition method is generally applicable to large geographical environments such as mountains and rivers, but it is limited in its ability to detect local terrain, and has problems such as low efficiency, high cost, and complex data processing. Summary of the invention

[0003] The present invention aims to solve the shortcomings of the existing method for detecting local terrain, and provides a device and method for detecting local terrain.

[0004] To solve the above problems, the present invention is achieved through the following technical solutions:

[0005] A device for detecting local terrain is composed of an electric control mechanism, a spherical mechanism and a walking mechanism. The electric control mechanism includes an electric control platform, and an industrial computer module, a liquid crystal display module, a DSP module, a driver module and an inertial measurement unit arranged on the electric control platform; the electric control platform is arranged horizontally; the output ends of the inertial measurement unit, the spherical measurement incremental encoder and the grating ruler of the spherical device, and the walking measurement incremental encoder of the walking mechanism are connected to the input end of the DSP module; the DSP module is connected to the industrial computer module; the output end of the industrial computer module is connected to the input end of the walking drive motor of the walking mechanism via the driver module; the output end of the industrial computer module is connected to the input end of the liquid crystal display module. The spherical mechanism comprises a spherical shell, a sphere, more than three springs, a grating ruler, more than three spherical measuring omnidirectional wheels and more than three spherical measuring incremental encoders; the spherical shell is in a hollow inverted truncated cone shape, and the upper bottom surface and the lower bottom surface of the spherical shell are both arranged horizontally; the upper ends of more than three springs are connected to the electric control platform, and the lower ends of more than three springs are connected to the upper bottom surface of the spherical shell; the grating ruler is arranged vertically, and the two ends of the grating ruler are respectively connected to the lower surface of the electric control platform and the upper surface of the spherical shell; a circular embedded hole is opened on the lower bottom surface of the spherical shell, and ... grating ruler is arranged vertically, and the grating ruler is arranged vertically, and the grating ruler is arranged vertically, and the grating ruler is arranged vertically, and the grating The diameter of the embedded hole is smaller than the diameter of the sphere; the sphere is arranged inside the spherical shell, the upper end of the sphere is tangent to the lower bottom surface of the spherical shell, and the lower end of the sphere extends out of the spherical shell from the embedded hole; more than three spherical measuring omnidirectional wheels are arranged inside the spherical shell, and the U-shaped brackets of more than three spherical measuring omnidirectional wheels are hinged on the side of the spherical shell; the surfaces of more than three spherical measuring omnidirectional wheels are tangent to the surface of the sphere; the number of spherical measuring omnidirectional wheels and spherical measuring incremental encoders is the same, and the spherical measuring incremental encoders are arranged next to the corresponding spherical measuring omnidirectional wheels. The walking mechanism includes more than 3 rigid support rods, more than 3 walking omnidirectional wheels, more than 3 walking measurement incremental encoders and more than 2 walking drive motors; the upper ends of the more than 3 rigid support rods are connected to the electric control platform, and the lower ends of the more than 3 rigid support rods are respectively hinged to the U-shaped brackets of the more than 3 walking omnidirectional wheels; more than 2 walking drive motors are respectively connected to more than 2 walking omnidirectional wheels; the number of walking omnidirectional wheels and walking measurement incremental encoders is the same, and the walking measurement incremental encoders are arranged next to the corresponding walking omnidirectional wheels.

[0006] In the above scheme, the spherical mechanism is located in the middle of the lower part of the electric control mechanism, and the walking mechanism is located on the lower outer side of the electric control mechanism.

[0007] In the above scheme, both the spherical mechanism and the walking mechanism are symmetrical structures about the longitudinal central axis, and the longitudinal central axes of the spherical mechanism and the walking mechanism coincide with each other and pass through the center of the electric control platform.

[0008] In the above scheme, the tangent points between the surfaces of all spherical measuring omnidirectional wheels and the surface of the sphere are at the same horizontal height.

[0009] In the above scheme, in the initial state, the grounding points of all the omnidirectional wheels and the grounding point of the ball are at the same horizontal height.

[0010] In the above scheme, a plurality of bull's eye wheels are further added at the tangent point between the lower bottom surface of the spherical shell and the upper end of the sphere and / or at the inner side of the embedded hole of the lower bottom surface of the spherical shell to contact the sphere.

[0011] A method for detecting local terrain implemented by the above device includes the following steps:

[0012] Step 1: Set the detection walking track of the road surface to be detected by the device for detecting local terrain through the industrial computer module. After the detection walking track is set, the industrial computer module drives the walking drive motor through the driver module to make the walking omnidirectional wheel move according to the preset detection walking track;

[0013] Step 2, the industrial computer module controls the DSP module to collect the three-axis body acceleration information returned by the inertial measurement unit, the spherical angular rate information returned by the spherical measurement incremental encoder, the displacement information returned by the grating ruler, and the walking angular rate information returned by the walking measurement incremental encoder according to a preset servo cycle;

[0014] Step 3: At each sampling moment, the spherical measurement incremental encoder based on the spherical mechanism calculates the first position of the grounding point of the sphere; that is:

[0015] First, the spherical angular velocity measured by more than three spherical measurement incremental encoders is transformed into a rotating coordinate matrix to obtain the rotation speed of the sphere; then, the linear velocity at the center of the sphere is calculated in combination with the diameter of the sphere and the rotation speed of the sphere; then, the linear velocity at the center of the sphere is projected to the geodetic coordinate system, and then integrated once to obtain the position of the grounding point of the sphere on the x-axis and y-axis in the geodetic coordinate system; then, the displacement measured by the grating ruler is used to obtain the position of the grounding point of the sphere on the z-axis in the geodetic coordinate system; finally, the first position of the grounding point of the sphere is obtained using the position of the grounding point of the sphere on the x-axis, y-axis and z-axis;

[0016] Step 4: At each sampling moment, the second position of the grounding point of the ball is calculated based on the inertial measurement unit of the electronic control mechanism; that is:

[0017] First, the body linear acceleration of the x-axis, y-axis and z-axis measured by the inertial measurement unit is projected into the earth coordinate system, and the position of the calibration point of the inertial measurement unit relative to the earth is obtained after two integrations; then, the second position of the grounding point of the sphere is calculated through the coordinate conversion relationship by combining the displacement measured by the grating ruler and the position of the calibration point of the inertial measurement unit relative to the earth;

[0018] Step 5: At each sampling moment, the third position of the grounding point of the ball is calculated based on the walking measurement incremental encoder of the walking mechanism; that is:

[0019] First, the walking angular rate measured by more than three walking measurement incremental encoders is used to calculate the positions of the contact points of more than three walking omnidirectional wheels; then, the body linear acceleration of the x-axis, y-axis and z-axis measured by the inertial measurement unit is projected to the earth coordinate system, and the position of the calibration point of the inertial measurement unit relative to the earth is obtained after two integrations; finally, the third position of the contact point of the sphere is calculated through the coordinate conversion relationship;

[0020] Step 6: Perform data fusion on the first position, the second position and the third position of the grounding point of the ball at each sampling time obtained in the Kalman filter steps 3-5 to obtain a set of grounding point positions of the ball;

[0021] Step 7: Derivative the gradient of the sphere grounding point position in the sphere grounding point position set, and finally construct a model of the road surface to be detected.

[0022] Compared with the prior art, the present invention has the following characteristics:

[0023] 1) The present invention provides a method for digitally and rapidly reconstructing the unevenness of local terrain, and provides a hardware architecture solution for a low-cost redundant detection device, which can effectively and accurately detect unknown terrain. At the same time, the present invention can be widely used in a variety of scenarios.

[0024] 2) In the existing radar laser scanning, there is a lack of accuracy and large visual errors. The present invention can accurately collect the model data of the terrain and reconstruct a three-dimensional model of the terrain. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of a device for detecting local terrain.

[0026] Figure 2 for Figure 1 BB section view.

[0027] Figure 3 for Figure 1 A three-dimensional diagram of .

[0028] Figure 4 The present invention is a flow chart of a method for detecting local terrain.

[0029] Figure 5 for Figure 4 Flowchart of the PATH1 part.

[0030] Figure 6 for Figure 4Flowchart of the PATH2 portion.

[0031] Figure 7 for Figure 4 Partial flow chart of PATH3.

[0032] Figure 8 This is a schematic diagram of the location of the spherical grounding point after data fusion.

[0033] Fig. 9 This is a schematic diagram of the location of the sphere's grounding point after gradient derivation.

[0034] Numbers in the figure: 1-1, electronically controlled platform, 1-2, inertial measurement unit; 2-1, spherical shell, 2-2, sphere, 2-3, spring, 2-4, grating ruler, 2-5, spherical measurement omnidirectional wheel, 2-6, spherical measurement incremental encoder, 2-7, bull's eye wheel; 3-1, rigid support rod, 3-2, walking omnidirectional wheel, 3-3, walking measurement incremental encoder, 3-4, walking drive motor. DETAILED DESCRIPTION

[0035] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific examples.

[0036] A device for detecting local terrain, such as Figure 1 and 2 As shown, it is mainly composed of three major mechanisms: an electric control mechanism, a spherical 2-2 mechanism and a walking mechanism.

[0037] The electric control mechanism includes an electric control platform 1-1, and an industrial computer module, a liquid crystal display module, a DSP module, a driver module and an inertial measurement unit 1-2 arranged on the electric control platform 1-1. The electric control platform 1-1 is arranged horizontally. The output end of the inertial measurement unit 1-2, the spherical measurement incremental encoder 2-6 and the grating ruler 2-4 of the sphere 2-2-shaped device, and the walking measurement incremental encoder 3-3 of the walking mechanism are connected to the input end of the DSP module through a wired or wireless manner. The DSP module is connected to the industrial computer module. The output end of the industrial computer module is connected to the input end of the walking drive motor 3-4 of the walking mechanism via the driver module. The output end of the industrial computer module is connected to the input end of the liquid crystal display module.

[0038] The spherical 2-2-shaped mechanism includes a spherical shell 2-1, a sphere 2-2, more than three springs 2-3, a grating ruler 2-4, more than three spherical measurement omnidirectional wheels 2-5 and more than three spherical measurement incremental encoders 2-6. The spherical shell 2-1 is in the shape of a hollow inverted truncated cone, and the upper bottom surface and the lower bottom surface of the spherical shell 2-1 are both arranged horizontally. The spherical 2-2-shaped mechanism is located in the lower middle part of the electric control mechanism, and the spherical 2-2-shaped mechanism is connected to the electric control mechanism by springs 2-3. The upper ends of more than three springs 2-3 are connected to the electric control platform 1-1, and the lower ends of more than three springs 2-3 are connected to the upper bottom surface of the spherical shell 2-1. The grating ruler 2-4 is arranged vertically, and the two ends of the grating ruler 2-4 are respectively connected to the lower surface of the electric control platform 1-1 and the upper surface of the spherical shell 2-1. The lower bottom surface of the spherical shell 2-1 is provided with a circular embedding hole, the diameter of which is smaller than the diameter of the sphere 2-2. The sphere 2-2 is arranged inside the spherical shell 2-1, the upper end of the sphere 2-2 is tangent to the lower bottom surface of the spherical shell 2-1, and the lower end of the sphere 2-2 extends from the embedding hole to the outside of the spherical shell 2-1. In order to ensure the stability of the installation of the sphere 2-2, at the place where the lower bottom surface of the spherical shell 2-1 is tangent to the upper end of the sphere 2-2, a plurality of bull's eye wheels 2-7 are added to the inner side of the embedding hole of the lower bottom surface of the spherical shell 2-1 to contact the sphere 2-2, so as to ensure that the sphere 2-2 can maintain stable free rotation during walking. More than three spherical measuring omnidirectional wheels 2-5 are arranged inside the spherical shell 2-1, and the U-shaped brackets of more than three spherical measuring omnidirectional wheels 2-5 are hinged on the side of the spherical shell 2-1. The surfaces of more than three spherical measurement omnidirectional wheels 2-5 are tangent to the surface of the sphere 2-2, and the tangent points of the surfaces of all spherical measurement omnidirectional wheels 2-5 and the surfaces of the sphere 2-2 are at the same horizontal height. The number of spherical measurement omnidirectional wheels 2-5 and spherical measurement incremental encoders 2-6 is the same, and the spherical measurement incremental encoders 2-6 are arranged next to the corresponding spherical measurement omnidirectional wheels 2-5.

[0039] The walking mechanism includes more than three rigid support rods 3-1, more than three walking omnidirectional wheels 3-2, more than three walking measurement incremental encoders 3-3 and more than two walking drive motors 3-4. The walking mechanism is located below and outside the electric control mechanism, and the walking mechanism and the electric control mechanism are rigidly connected. The upper ends of the more than three rigid support rods 3-1 are connected to the electric control platform 1-1, and the lower ends of the more than three rigid support rods 3-1 are respectively hinged to the U-shaped brackets of more than three walking omnidirectional wheels 3-2. The lower ends of all the walking omnidirectional wheels 3-2 are at the same horizontal height as the lower end of the ball 2-2. More than two walking drive motors 3-4 are respectively connected to more than two walking omnidirectional wheels 3-2, and the connection relationship between the drive motor and the walking omnidirectional wheel 3-2 can be coaxial, or it can be a connection with a certain meshing relationship, such as a gear meshing connection with a certain reduction ratio. The number of the walking omnidirectional wheels 3 - 2 and the walking measurement incremental encoders 3 - 3 is the same, and the walking measurement incremental encoders 3 - 3 are arranged beside the corresponding walking omnidirectional wheels 3 - 2 .

[0040] In order to simplify the subsequent calculations for detecting local terrain, the device for detecting local terrain is overall longitudinally centrally symmetrical, that is, the spherical 2-2-shaped mechanism and the walking mechanism are both longitudinally central axis symmetrical structures, and the longitudinal central axes of the spherical 2-2-shaped mechanism and the walking mechanism coincide and pass through the center of the electric control platform 1-1; the inertial measurement unit 1-2 is fixed at the center of the electric control platform 1-1; the upper end of the grating scale 2-4 is fixed at the center of the lower surface of the electric control platform 1-1, and the lower end of the grating scale 2-4 is fixed at the center of the upper surface of the spherical shell 2-1. In this embodiment, the number of the springs 2-3, the spherical measuring omnidirectional wheels 2-5 and the spherical measuring incremental encoders 2-6 of the spherical 2-2 shaped mechanism are all 3, and the springs 2-3 and the springs 2-3, the spherical measuring omnidirectional wheels 2-5 and the spherical measuring omnidirectional wheels 2-5, and the spherical measuring incremental encoders 2-6 and the spherical measuring incremental encoders 2-6 are centrally symmetrically distributed with each other; the number of the rigid support rods 3-1, the walking omnidirectional wheels 3-2, the walking measuring incremental encoders 3-3 and the walking drive motors 3-4 of the walking mechanism are all 3, and the rigid support rods 3-1 and the rigid support rods 3-1, the walking omnidirectional wheels 3-2 and the walking omnidirectional wheels 3-2, the walking measuring incremental encoders 3-3 and the walking measuring incremental encoders 3-3, and the walking drive motors 3-4 and the walking drive motors 3-4 are centrally symmetrically distributed with each other.

[0041] Figure 3This is a three-dimensional schematic diagram of the device for detecting local terrain. Given the position information of the contact point between the ball 2-2 and the ground, the position information of the ball 2-2 in the geodetic coordinate system can be determined through the spherical measurement incremental encoder 2-6 and the grating ruler 2-4 of the spherical mechanism. The linear acceleration on the three axes collected by the inertial measurement unit 1-2 is projected to the geodetic coordinate system, and the position information of the inertial measurement unit 1-2 in the geodetic coordinate system is determined through two integral calculations, and the position information of the grounding point of the ball 2-2 is further determined. The position information of the three omnidirectional wheels on the x-axis and y-axis in the geodetic coordinate system can be determined through the walking measurement incremental encoder 3-3 of the walking mechanism, and the position information of the grounding point of the ball 2-2 is further determined through the rotational transformation relationship between the mechanical structure of the device and the system coordinate system. The discrete position information obtained above is fused through Kalman filtering, and the gradient derivative of the fused data is performed to construct a terrain model.

[0042] Specifically, the above device implements a method for detecting local terrain, such as Figure 4 As shown, it mainly includes the following steps:

[0043] Step 1: Analyze the terrain to be tested, and reasonably set the walking track of the terrain detection device on the road to be tested to ensure that the device can traverse the terrain to be tested. The detection walking track of the device for detecting local terrain on the road to be tested is set through the industrial computer module. After the detection walking track is set, the industrial computer module drives the walking drive motor 3-4 through the driver module to make the walking omnidirectional wheel 3-2 move according to the preset detection walking track.

[0044] Step 2: Set the sampling servo cycle to collect information from each sensor at every moment during the movement of the device.

[0045] The industrial computer module controls the DSP module to collect the three-axis body acceleration information returned by the inertial measurement unit 1-2, the spherical angular rate information returned by the spherical measurement incremental encoder 2-6, the displacement information returned by the grating ruler 2-4, and the walking angular rate information returned by the walking measurement incremental encoder 3-3 according to the preset servo cycle.

[0046] Step 3: At each sampling moment, the spherical measurement incremental encoder 2-6 based on the spherical mechanism calculates the first position (x1, y1, z1) of the grounding point D' of the sphere 2-2, see Figure 5 .

[0047] When the device is moving on the road surface to be detected, the omnidirectional wheels 3-2 are used to drive the device to control its movement direction and path. The ball 2-2 in the ball 2-2 shaped mechanism will directly contact the ground and rotate as the device moves.

[0048] Step 3.1: The spherical angular velocity measured by more than three spherical measurement incremental encoders 2-6 is transformed into the rotational coordinate matrix of robotics to obtain the rotational speed ω of the sphere 2-2. M ;

[0049] ω M =(ω Mx ω My ω Mz )

[0050] Step 3.2: Calculate the linear velocity V at the center M of the sphere 2-2 by combining the constraint relationship between the center M of the sphere 2-2 and the grounding point D' (i.e., the diameter of the sphere 2-2) and the rotation speed of the sphere 2-2. M , where V M =ω M ·l MD′ Next, the linear velocity at the center M of the sphere 2-2 is projected to the geodetic coordinate system, and then integrated once to obtain the x-axis and y-axis positions x1 and y1 of the grounding point D' of the sphere 2-2 in the geodetic coordinate system;

[0051]

[0052]

[0053] in is the rotation transformation matrix of the M system relative to the geodetic coordinate system, (*)[1] is the first term of the * vector, and (*)[2] is the second term of the * vector;

[0054] Step 3.3, since the electric control mechanism and the spherical mechanism have relative motion only in the vertical direction, the displacement of the grating ruler 2-4 installed between the spherical mechanism and the electric control mechanism is obtained, and the relative displacement between the spherical mechanism and the electric control mechanism can be obtained. In this way, the displacement measured by the grating ruler 2-4 is used to obtain the point position z1 of the grounding point D' of the sphere 2-2 on the z-axis in the geodetic coordinate system;

[0055] Step 3.4, using the x-axis, y-axis and z-axis positions of the grounding point D' of the sphere 2-2, obtain the first position (x1, y1, z1) of the grounding point D' of the sphere 2-2.

[0056] Step 4: At each sampling moment, the inertial measurement unit 1-2 of the electronic control mechanism calculates the second position (x2, y2, z2) of the grounding point D' of the ball 2-2, see Figure 6 .

[0057] Step 4.1: The linear acceleration a of the x-axis, y-axis and z-axis measured by the inertial measurement unit 1-2 is x 、a y 、a zProject it to the earth coordinate system and perform two integrations to obtain the position X of the calibration point D of the inertial measurement unit 1-2 relative to the earth. D , which can be calculated where a=(a x a y a z );

[0058] Step 4.2, since there is only relative movement in the vertical direction between the electric control mechanism and the spherical mechanism, the displacement of the grating ruler 2-4 installed between the spherical mechanism and the electric control mechanism is obtained, and the relative displacement between the spherical mechanism and the electric control mechanism can be obtained. In this way, the displacement measured by the grating ruler 2-4 and the position of the calibration point D of the inertial measurement unit 1-2 relative to the earth are combined, and the second position (x2, y2, z2) of the grounding point D' of the sphere 2-2 is calculated through the coordinate transformation relationship.

[0059] Step 5: At each sampling moment, the third position (x3, y3, z3) of the grounding point D' of the ball 2-2 is calculated based on the walking measurement incremental encoder 3-3 of the walking mechanism, see Figure 7 .

[0060] When the device is traveling on the road surface to be detected, the omnidirectional wheels 3-2 in the traveling mechanism are in contact with the ground.

[0061] Step 5.1: Use more than three walking measurement incremental encoders 3-3 to measure the walking angular rate ω A′ ,ω B′ ,ω C′ ,……;

[0062] Step 5.2: Project the body linear acceleration of the x-axis, y-axis and z-axis measured by the inertial measurement unit 1-2 to the earth coordinate system, and perform two integrations to obtain the position of the calibration point of the inertial measurement unit 1-2 relative to the earth. Combined with the angular rates of the three or more running wheels obtained in step 5.1, the positions X of the three or more running wheels are calculated. A′ , X B′ , X C′ ,……;

[0063] Step 5.3, the electric control platform 1-1 and the spherical device platform have relative motion only in the vertical direction, and the position of the ball grounding point can be determined by coordinate transformation, that is, the third position (x3, y3, z3) of the grounding point of the sphere 2-2;

[0064] Step 6: The first position, the second position and the third position of the grounding point of the ball 2-2 at each sampling time obtained in the Kalman filter step 3-5 are used to fuse data to obtain a position set of the grounding point of the ball 2-2. Figure 8As shown, the point information shown in the figure is the data information after data fusion.

[0065] Step 7: Derivative the gradient of the grounding point position of the ball 2-2 in the grounding point position set of the ball 2-2, and finally construct a model of the road surface to be detected. Fig. 9 As shown, the point information shown in the figure is the data information after gradient derivation.

[0066] Select any terrain data with a boundary range for processing. The point information (x i ,y i , z i , i = 1 ~ n), find the partial derivatives of two adjacent points, which is defined as:

[0067]

[0068] in, and They are the gradients along the x, y and z directions respectively, and the magnitude of the gradient is:

[0069]

[0070] Using differences instead of differential terrain gradients And the modulus N of the gradient can be expressed as:

[0071]

[0072] From this we can get the gradient direction Expressed as

[0073]

[0074] In the above manner, the collected ground information is divided into boundaries and the directional derivatives in each boundary area are calculated respectively, and finally the data is fitted to construct the detected terrain model.

[0075] The method of the present invention can effectively and accurately obtain terrain data information, greatly improving the accuracy of unknown terrain models.

[0076] It should be noted that although the embodiments of the present invention described above are illustrative, they are not intended to limit the present invention, and therefore the present invention is not limited to the above specific embodiments. Without departing from the principles of the present invention, any other embodiments obtained by those skilled in the art under the guidance of the present invention are deemed to be within the protection of the present invention.

Claims

1. A device for detecting local terrain, characterized in that: It is composed of an electric control mechanism, a spherical mechanism and a walking mechanism; The electric control mechanism comprises an electric control platform (1-1), and an industrial computer module, a liquid crystal display module, a DSP module, a driver module and an inertial measurement unit (1-2) arranged on the electric control platform (1-1); the electric control platform (1-1) is arranged horizontally; the output ends of the inertial measurement unit (1-2), the spherical surface measurement incremental encoder (2-6) and the grating ruler (2-4) of the spherical device, and the walking measurement incremental encoder (3-3) of the walking mechanism are connected to the input end of the DSP module; The DSP module is connected to the industrial computer module; the output end of the industrial computer module is connected to the input end of the travel drive motor (3-4) of the travel mechanism via the driver module; the output end of the industrial computer module is connected to the input end of the liquid crystal display module; The spherical mechanism comprises a spherical shell, a sphere (2-2), more than three springs (2-3), a grating ruler (2-4), more than three spherical surface measurement omnidirectional wheels (2-5) and more than three spherical surface measurement incremental encoders (2-6); the spherical shell is in the shape of a hollow inverted truncated cone, and the upper bottom surface and the lower bottom surface of the spherical shell are both arranged horizontally; the upper ends of the more than three springs (2-3) are connected to an electric control platform (1-1), and the lower ends of the more than three springs (2-3) are connected to the upper bottom surface of the spherical shell; the grating ruler (2-4) is arranged vertically, and the two ends of the grating ruler (2-4) are respectively connected to the lower surface of the electric control platform (1-1) and the upper surface of the spherical shell; a circular embedded hole is opened on the lower bottom surface of the spherical shell, and the embedded hole The diameter of the spherical shell is smaller than the diameter of the sphere (2-2); the sphere (2-2) is arranged inside the spherical shell, the upper end of the sphere (2-2) is tangent to the lower bottom surface of the spherical shell, and the lower end of the sphere (2-2) extends out of the spherical shell from the embedding hole; more than three spherical surface measurement omnidirectional wheels (2-5) are arranged inside the spherical shell, and the U-shaped brackets of more than three spherical surface measurement omnidirectional wheels (2-5) are hinged on the side of the spherical shell; the surfaces of more than three spherical surface measurement omnidirectional wheels (2-5) are tangent to the surface of the sphere (2-2); the number of the spherical surface measurement omnidirectional wheels (2-5) and the spherical surface measurement incremental encoder (2-6) is the same, and the spherical surface measurement incremental encoder (2-6) is arranged beside the corresponding spherical surface measurement omnidirectional wheels (2-5); The walking mechanism comprises more than three rigid support rods (3-1), more than three walking omnidirectional wheels (3-2), more than three walking measurement incremental encoders (3-3) and more than two walking drive motors (3-4); the upper ends of the more than three rigid support rods (3-1) are connected to the electric control platform (1-1), and the lower ends of the more than three rigid support rods (3-1) are respectively hinged to the U-shaped brackets of the more than three walking omnidirectional wheels (3-2); more than two walking drive motors (3-4) are respectively connected to the more than two walking omnidirectional wheels (3-2); the number of the walking omnidirectional wheels (3-2) and the walking measurement incremental encoders (3-3) is the same, and the walking measurement incremental encoders (3-3) are arranged beside the corresponding walking omnidirectional wheels (3-2).

2. The device for detecting local terrain according to claim 1, characterized in that: The spherical mechanism is located in the middle of the lower part of the electric control mechanism, and the walking mechanism is located on the outer side of the lower part of the electric control mechanism.

3. The device for detecting local terrain according to claim 1, characterized in that the spherical The mechanism and the walking mechanism are both longitudinal central axis symmetrical structures, and the longitudinal central axes of the spherical mechanism and the walking mechanism coincide with each other and pass through the center of the electric control platform (1-1).

4. The device for detecting local terrain according to claim 1, characterized in that: The tangent points of the surfaces of all spherical measuring omnidirectional wheels (2-5) and the surface of the sphere (2-2) are at the same horizontal height.

5. The device for detecting local terrain according to claim 1, characterized in that: In the initial state, the grounding points of all the walking omnidirectional wheels (3-2) and the grounding point of the ball (2-2) are at the same level.

6. The device for detecting local terrain according to claim 1, characterized in that: A plurality of bull's eye wheels (2-7) are added at the tangent point between the lower bottom surface of the spherical shell and the upper end of the sphere (2-2) and / or at the inner side of the embedded hole of the lower bottom surface of the spherical shell to contact the sphere (2-2).

7. A method for detecting local terrain implemented by the device of claim 1, characterized in that: The steps include: Step 1: Setting the detection walking track of the road surface to be detected by the device for detecting local terrain through the industrial computer module; after the detection walking track is set, the industrial computer module drives the walking drive motor (3-4) through the driver module to make the walking omnidirectional wheel (3-2) move according to the preset detection walking track; Step 2, the industrial computer module controls the DSP module to collect the three-axis body acceleration information returned by the inertial measurement unit (1-2), the spherical angular velocity information returned by the spherical measurement incremental encoder (2-6), the displacement information returned by the grating ruler (2-4), and the walking angular velocity information returned by the walking measurement incremental encoder (3-3) according to a preset servo cycle; Step 3: At each sampling moment, the spherical measurement incremental encoder (2-6) based on the spherical mechanism calculates the first position of the grounding point of the sphere (2-2); that is: First, the spherical angular velocity measured by more than three spherical measurement incremental encoders (2-6) is transformed into a rotational coordinate matrix to obtain the rotation speed of the sphere (2-2); then, the linear velocity at the center of the sphere (2-2) is calculated in combination with the diameter of the sphere (2-2) and the rotation speed of the sphere (2-2); then, the linear velocity at the center of the sphere (2-2) is projected into the geodetic coordinate system, and after an integration, the position of the grounding point of the sphere (2-2) on the x-axis and y-axis in the geodetic coordinate system is obtained; then, the displacement measured by the grating ruler (2-4) is used to obtain the position of the grounding point of the sphere (2-2) on the z-axis in the geodetic coordinate system; finally, the first position of the grounding point of the sphere (2-2) is obtained using the position of the grounding point of the sphere (2-2) on the x-axis, y-axis and z-axis; Step 4: At each sampling moment, the second position of the grounding point of the sphere (2-2) is calculated based on the inertial measurement unit (1-2) of the electronic control mechanism; that is: First, the body linear accelerations of the x-axis, y-axis and z-axis measured by the inertial measurement unit (1-2) are projected into the earth coordinate system, and the position of the calibration point of the inertial measurement unit (1-2) relative to the earth is obtained after two integrations; then, the second position of the grounding point of the sphere (2-2) is calculated through a coordinate conversion relationship by combining the displacement measured by the grating ruler (2-4) and the position of the calibration point of the inertial measurement unit (1-2) relative to the earth; Step 5: At each sampling moment, the third position of the grounding point of the ball (2-2) is calculated based on the walking measurement incremental encoder (3-3) of the walking mechanism; that is: First, the walking angular velocity measured by more than three walking measurement incremental encoders (3-3) is used to calculate the positions of the contact points of more than three walking omnidirectional wheels (3-2); then, the body linear accelerations of the x-axis, y-axis and z-axis measured by the inertial measurement unit (1-2) are projected into the earth coordinate system, and the position of the calibration point of the inertial measurement unit (1-2) relative to the earth is obtained after two integrations; finally, the third position of the contact point of the sphere (2-2) is calculated through the coordinate conversion relationship; Step 6: Perform data fusion on the first position, the second position and the third position of the grounding point of the sphere (2-2) at each sampling time obtained in the Kalman filter step 3-5 to obtain a set of grounding point positions of the sphere (2-2); Step 7, derive the gradient of the grounding point position of the sphere (2-2) in the grounding point position set, and finally construct a model of the road surface to be detected.

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