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CN-121978597-A - Multi-degree-of-freedom automatic obstacle avoidance space magnetic field measurement method and system

CN121978597ACN 121978597 ACN121978597 ACN 121978597ACN-121978597-A

Abstract

The invention discloses a multi-degree-of-freedom automatic obstacle avoidance space magnetic field measurement method and system, wherein the method comprises the steps that an upper computer issues an instruction according to a global coordinate system, a PLC drives a Z-axis and R-axis module to cooperatively move, a rotation detection mechanism is conveyed to a coarse positioning point in a tank, a microcontroller plans an obstacle avoidance path through laser scanning data, and drives the robot to move The internal orthogonal Hall sensor collects magnetic field components, and the microcontroller performs coordinate transformation operation in combination with real-time angles to synthesize accurate three-dimensional magnetic field intensity data of the target point. According to the technical scheme, the multi-degree-of-freedom automatic obstacle avoidance and flexible detection in the complex closed space are realized, the problem that the traditional rigid structure is easy to collide and has a measurement blind area is effectively solved, the automatic acquisition of high-precision three-dimensional magnetic field data can be completed without manual intervention, and the safety, the efficiency and the data accuracy of measurement are improved.

Inventors

  • ZHANG SAI
  • HU LIANG
  • HUANG YANGYANG
  • WANG BOWEN
  • Jin Yuyue

Assignees

  • 长沙理工大学

Dates

Publication Date
20260505
Application Date
20260409

Claims (10)

  1. 1. The method for measuring the magnetic field of the multi-degree-of-freedom automatic obstacle avoidance space is characterized by comprising the following steps of: S1, an upper computer issues a measurement task instruction containing the three-dimensional coordinates of a target point to a PLC control unit according to a preset space global coordinate system to be measured, the PLC control unit analyzes the measurement task instruction and drives a Z-axis lifting module and an R-axis stretching module to execute cooperative motion, a rotation detection mechanism arranged at the tail end of an R-axis is conveyed to a preset coarse positioning coordinate point in a tank to be measured, and therefore the height reference and the radial reference position of the rotation detection mechanism under a cylindrical coordinate system are established; s2, based on the height reference and the radial reference position, a microcontroller activates a laser ranging module integrated on the rotation detection mechanism to scan and range the front sector area, and generates a circumferential rotation control instruction containing obstacle avoidance path planning according to distance data obtained by scanning to drive The shaft rotating mechanism drives the rotation detecting mechanism to rotate around the central line of the R shaft, and adjusts the gesture until the gesture reaches the barrier-free target measurement gesture; And S3, under the condition that the rotation detection mechanism is maintained in the target measurement attitude, three linear Hall sensors which are orthogonally arranged in the rotation detection mechanism sense a space magnetic field vector at the current position and output corresponding three paths of analog voltage signals, and a microcontroller acquires the three paths of analog voltage signals and combines the real-time angle value of the target measurement attitude to perform coordinate transformation operation to synthesize and obtain accurate three-dimensional magnetic field intensity data at the target point.
  2. 2. The method for measuring the magnetic field of the multi-degree-of-freedom automatic obstacle avoidance space according to claim 1, wherein in S2, generating a circumferential rotation control command including obstacle avoidance path planning according to the distance data obtained by scanning includes: s21, the laser ranging module continuously performs multi-point ranging on the sector section in the advancing direction of the rotary detection mechanism according to preset angle resolution, and environment depth matrix data containing a plurality of partition distance values is generated; s22, the microcontroller reads the environmental depth matrix data, compares the distance value of each partition in the matrix with a preset safety distance threshold value one by one, screens out an abnormal partition set with the distance value smaller than the safety distance threshold value, and fits the geometric outline and the central position coordinate of the potential obstacle based on the space topological relation of the abnormal partition set; S23, planning a obstacle avoidance track which can bypass the geometric outline and has the minimum path cost function in a preset motion space grid map through an A-path search algorithm aiming at the fitted geometric outline and central position coordinates of the obstacle, and discretizing and converting the obstacle avoidance track into a time-pulse sequence corresponding to a motor to serve as the circumferential rotation control instruction.
  3. 3. The method for measuring the magnetic field of the multi-degree-of-freedom automatic obstacle avoidance space according to claim 2, wherein the step S23 of discretizing the obstacle avoidance trajectory into a time-pulse sequence corresponding to the motor comprises the steps of: S231, if the fitted geometric outline of the obstacle is positioned right in front of the current motion track of the rotation detection mechanism and the nearest distance is smaller than a preset dangerous distance threshold, the PLC control unit analyzes a backspacing sub-instruction in the obstacle avoidance track, and preferentially drives the R-axis telescoping module to reversely rotate so that the rotation detection mechanism rolls back a preset safe buffering distance along a radial axis; S232, at a safe position after the rotation detection mechanism finishes the radial shaft retraction, the PLC control unit drives the rotation detection mechanism according to the detour angle parameters in the obstacle avoidance track The shaft rotating mechanism deflects to a preset avoiding angle, and then the R-shaft telescopic module is driven to resume radial feeding action until the rotating detection mechanism bypasses the obstacle and resets to the target measuring posture.
  4. 4. The method for measuring the magnetic field of the multi-degree-of-freedom automatic obstacle avoidance space according to claim 1, wherein in the S1, driving the Z-axis lifting module and the R-axis stretching module to perform cooperative movement comprises: S11, the PLC control unit calculates the target pulse number of the Z-axis stepping motor according to the height coordinate parameter in the measurement task instruction, and sends the target pulse number to the Z-axis driver through the pulse output port to drive the ball screw to rotate so as to drive the bearing platform to vertically lift to a target height surface aligned with the central axis of the tank body along the linear guide rail; And S12, after the bearing platform is stably stopped on the target height surface, the PLC control unit controls a friction wheel driving motor arranged on the outer wall of the R shaft to start according to the radial depth parameter in the measurement task instruction, and drives the R shaft hollow pipe to axially extend or retract through static friction force between the friction wheel and the R shaft hollow pipe wall until the tail end of the R shaft reaches the target radial depth, so that the physical positioning of the preset coarse positioning coordinate point is completed.
  5. 5. The method for measuring the magnetic field of the multi-degree-of-freedom automatic obstacle avoidance space according to claim 1, wherein in S3, collecting the three analog voltage signals comprises: s31, the three linear Hall sensors induce magnetic fields under the excitation of a constant voltage source power supply loop, and respectively output single-ended analog voltage signals containing magnetic field induction components and common mode interference noise, wherein the single-ended analog voltage signals are transmitted to a front-end signal conditioning circuit through a shielded twisted pair; S32, the front-end signal conditioning circuit receives the single-end analog voltage signal, converts the single-end analog voltage signal into a differential signal through an instrument amplifier with high common mode rejection ratio, performs primary gain amplification, and outputs a differential analog signal with high signal to noise ratio after filtering power frequency interference in a transmission process based on a low-pass filter; S33, the analog-to-digital conversion module carries out high-frequency trigger sampling on the differential analog signals for a plurality of times, calculates the arithmetic mean of the residual effective sampling values after removing the coarse error values in the sampling sequence through the 3 sigma criterion, and provides the arithmetic mean as effective voltage sampling data for the microcontroller.
  6. 6. The method for measuring the magnetic field in the multi-degree-of-freedom automatic obstacle avoidance space according to claim 1, wherein in S3, the coordinate transformation operation is performed in combination with the real-time angle value of the target measurement attitude, comprising: s34, in the whole process of executing the rotation action by the rotation detection mechanism, the rotation detection mechanism is connected with An absolute value encoder coaxially and rigidly connected with the shaft rotating mechanism monitors the angular displacement of the rotating shaft in real time, and locks the current actual physical angle value and feeds the current actual physical angle value back to the microcontroller when the rotating action stops; s35, the microcontroller receives the actual physical angle value, calculates the angle deviation between the actual physical angle value and the theoretical target angle, and constructs a rotation compensation matrix for correcting the magnetic field vector direction according to the angle deviation; S36, carrying out reverse rotation correction on an original magnetic field component vector obtained by converting three paths of analog voltage signals output by the linear Hall sensor according to the rotation compensation matrix, so as to eliminate magnetic field measurement component offset caused by mechanical positioning errors of the rotation detection mechanism.
  7. 7. The utility model provides a multi freedom is automatic keeps away barrier space magnetic field measurement system which characterized in that includes: The driving module is used for transmitting a measurement task instruction containing the three-dimensional coordinates of the target point to the PLC control unit by the upper computer according to a preset space global coordinate system to be measured, the PLC control unit analyzes the measurement task instruction and drives the Z-axis lifting module and the R-axis stretching module to execute cooperative motion, and a rotation detection mechanism arranged at the tail end of the R-axis is conveyed to a preset coarse positioning coordinate point in the tank to be measured, so that the height reference and the radial reference position of the rotation detection mechanism under the cylindrical coordinate system are established; the adjusting module is used for activating the laser ranging module integrated on the rotation detection mechanism to scan and range the front sector area based on the height reference and the radial reference position, generating a circumferential rotation control instruction containing obstacle avoidance path planning according to the distance data obtained by scanning, and driving The shaft rotating mechanism drives the rotation detecting mechanism to rotate around the central line of the R shaft, and adjusts the gesture until the gesture reaches the barrier-free target measurement gesture; And the synthesis module is used for sensing space magnetic field vectors of the current position and outputting corresponding three paths of analog voltage signals by three linear Hall sensors which are orthogonally arranged in the rotation detection mechanism under the condition that the rotation detection mechanism is maintained in the target measurement attitude, and the microcontroller acquires the three paths of analog voltage signals and combines real-time angle values of the target measurement attitude to perform coordinate transformation operation to synthesize and obtain accurate three-dimensional magnetic field intensity data at the target point.
  8. 8. The system of claim 7 wherein the drive module, the adjustment module, and the synthesis module are controlled to perform the method of any one of claims 2 to 6.
  9. 9. A computer readable storage medium, characterized in that the computer readable storage medium has stored therein a computer program which, when executed by a processor, implements the steps of the multiple degree of freedom automatic obstacle avoidance space magnetic field measurement method of any of claims 1 to 6.
  10. 10. A computer program product comprising a computer program which, when executed by a processor, implements the steps of the multiple degree of freedom automatic obstacle avoidance spatial magnetic field measurement method of any one of claims 1 to 6.

Description

Multi-degree-of-freedom automatic obstacle avoidance space magnetic field measurement method and system Technical Field The invention relates to the technical field of automatic detection, in particular to a multi-degree-of-freedom automatic obstacle avoidance space magnetic field measurement method and system. Background The Hall sensor is used as a magnetic field detection device based on the Hall effect, and is widely applied to precision fields such as motor magnetic field detection, space magnetic field mapping and the like because an output voltage signal and magnetic field intensity of the Hall sensor are in linear relation. In the existing spatial magnetic field measurement technical system, the main flow scheme is mainly divided into two types of orthogonal arrangement of multiple sensors and manual rotation of a single sensor. The multi-sensor orthogonal scheme realizes synchronous acquisition of X, Y, Z triaxial components by arranging three orthogonal sensors at the same measuring point, but has the defects of large quantity of sensors, large volume, high cost, difficulty in adapting to narrow measuring space, low angle adjustment precision, incapability of automatic operation and the like in the single-sensor manual rotation scheme, while the cost is reduced. The mechanical carrying structure in the prior art is generally based on a standard X, Y, Z three-dimensional module design, namely, a sensor is installed on a sliding block, and horizontal transverse displacement, lifting and advancing are realized by means of three-axis motor driving. When a rigid structure based on a rectangular coordinate system is used for long-distance detection, a cantilever of a forward shaft can bear huge mechanical load, so that the risk of structural deformation is increased. Meanwhile, the sensor module can only move along a linear track, and the single degree of freedom of movement determines that the attitude of the sensor module cannot be flexibly adjusted when facing complex geometric environments, so that the sensor module is difficult to reach a non-direct-view detection target position, and the flexibility and coverage range of magnetic field mapping are greatly limited. In specific industrial application scenes such as space plasma experiment equipment, the inside of a closed tank body of the equipment is not open environment, but complex barriers such as coils for generating a magnetic field, rigid support brackets and the like are distributed. After a traditional rotary sensor or a linear telescopic probe based on a three-dimensional module stretches into a tank, mechanical collision is very easy to occur once shielding exists on a motion path due to lack of a flexible obstacle avoidance mechanism. A slight crash can lead to a probe position shift, introducing a non-negligible measurement error, and a severe crash can cause a stuck rotating rod, an overload of the transmission mechanism and even permanent damage of the sensor core. In addition, in the closed space, the back of the obstacle often forms a measured shadow area, and a traditional linear motion mechanism cannot bypass the obstacle to send the sensor to the areas, so that the magnetic field data acquisition is incomplete. At present, no mature system is available in the industry, and the high-precision rotation angle adjustment and the intelligent obstacle detouring function can be simultaneously considered. To obtain complete data, existing solutions often rely on manual advance cleaning of obstacles in the tank or extremely inefficient manual adjustments, which not only greatly increase the time costs of the operation, but also involve extremely high safety risks for manual operations in experimental environments involving high pressures or special gases. Although the existing partial technical schemes attempt to solve the problems through the thought of low cost multi-sensor, for example, an integral rigid rotating rod made of ABS engineering plastic is matched with STM32 series microcontrollers and liquid crystal display modules, so that basic 0.5V-4.5V analog voltage signal acquisition and processing are realized, but the problem of mechanical movement of the core is not reached. The similar technical scheme adopts an anti-interference shielding design in the signal transmission module and realizes a certain degree of positioning by utilizing the telescopic bracket, but the signal transmission module is basically primary equipment only suitable for static and barrier-free ideal environments of a laboratory. When facing complex scenes such as an industrial closed tank body, the technology has three fundamental defects that firstly, the equipment cannot safely run in an unstructured environment due to complete lack of an obstacle avoidance function, secondly, the automation degree is low, path planning and self-adaptive adjustment cannot be realized, and thirdly, the signal acquisition blind area and the positioning accuracy are insuffic