Robotic arm and its operating method

Abstract

The present invention relates to a robot arm and an operating method thereof. The robot arm is used to press and arrange a monitoring instrument at the bottom of a detection well arranged on a planet. The robot arm comprises a base, a support assembly and a pressing assembly. The base is used to be in close contact with the monitoring instrument; the support assembly is arranged on the base, the support assembly comprises a support motor and a support rod, the support motor is connected to the support rod in a transmission manner, the support motor is used to drive the support rod to extend and retract along its own axial direction, the support rod is used to press against the well wall of the detection well to provide supporting force for the robot arm; the pressing assembly is arranged on the base, the pressing assembly comprises a pressing motor and a pressing rod, the pressing motor is connected to the pressing rod in a transmission manner, the pressing motor is used to drive the pressing rod to extend and retract along its own axial direction, the pressing rod is used to press against the monitoring instrument to lift the base from the surface of the monitoring instrument and realize the posture adjustment of the robot arm, and the pressing rod is also used to press and adjust the posture of the monitoring instrument.

Description

Technical Field

[0001] The present invention relates to the technical field of planetary exploration, and particularly to a robotic arm and an operation method thereof. Background Art

[0002] In recent years, China's deep space exploration cause has advanced by leaps and bounds, achieving unprecedented progress in various fields. The exploration of the internal layer structure of terrestrial planets has also been gradually put on the agenda. The exploration of the internal layer structure of planets mainly relies on seismic signals collected by seismographs, and the performance parameters of seismographs are greatly affected by the surface environmental temperature. Considering that China already has the idea of drilling wells on the lunar surface, it is expected to borrow well holes to deploy downhole seismographs when deploying seismographs on the planet surface in the future, so as to utilize the low temperature and constant temperature conditions below the surface, which is conducive to improving the temperature stability of the seismograph's observation environment, obtaining high-quality observation data, and promoting major scientific outputs.

[0003] When deploying a seismograph in a well, since the soil properties and particle sizes on the surface of each planet are not yet clear, and large particles in the soil will block or affect the seismograph from sitting at the bottom of the well, and even affect the coupling between the seismograph and the bottom surface of the well. Therefore, at present, it is necessary to ensure that the instrument can sit at the bottom and remain pressed during the unmanned deployment at the bottom of the well, so as to avoid unstable posture of the instrument and affect the consistency of the observation data. Summary of the Invention

[0004] Based on this, it is necessary to provide a robotic arm and an operation method thereof to solve the problem that the monitoring instrument fails to sit at the bottom of the well due to stone protrusions on the well wall of the exploration well or unevenness at the bottom of the well.

[0005] A robotic arm for tightly arranging a monitoring instrument at the bottom of a detection well provided on a planet, the robotic arm comprising:

[0006] A base for closely adhering to the monitoring instrument;

[0007] A support assembly disposed on the base, the support assembly including a support motor and a support rod, the support motor being in transmission connection with the support rod, the support motor being configured to drive the support rod to axially extend and contract along its own axis, and the support rod being configured to abut against the well wall of the detection well to provide a support force for the robotic arm; and

[0008] A pressing assembly disposed on the base, the pressing assembly including a pressing motor and a pressing rod, the pressing motor being in transmission connection with the pressing rod, the pressing motor being configured to drive the pressing rod to axially extend and contract along its own axis, the pressing rod being configured to abut against the monitoring instrument to lift the base from the surface of the monitoring instrument and achieve the posture adjustment of the robotic arm, and the pressing rod being further configured to tightly press and adjust the posture of the monitoring instrument.

[0009] In one embodiment, the support assembly and the pressing assembly both include a plurality of them. The plurality of support assemblies are spaced apart and arranged on the base, and the plurality of pressing assemblies are spaced apart and arranged on the base.

[0010] In one embodiment, the robotic arm further includes a first sensor and / or a second sensor. The first sensor is disposed on the support rod, and the first sensor is used to detect the abutting force exerted by the support rod on the well wall of the exploration well. The second sensor is disposed on the pressing rod, and the second sensor is used to detect the abutting force exerted by the pressing rod on the monitoring instrument.

[0011] In one embodiment, the robotic arm further includes a control board. The control board is disposed on the base and is electrically connected to the support motor and the pressing motor.

[0012] In one embodiment, the robotic arm further includes a third sensor. The third sensor is disposed on the control board, and the third sensor is used to detect the attitude information of the robotic arm.

[0013] In one embodiment, the base is of a box structure. The cross-section of the base is in a circular ring shape. The base has a central through hole for the power supply and communication cable of the monitoring instrument to pass through. The base includes a base and a box cover disposed opposite to each other. The base and the box cover are coaxially arranged. Both the base and the box cover are provided with the central through hole. The support motor and the pressing motor are both disposed on the base.

[0014] In one embodiment, the support motor is fixed to the base by a coupling cone. The pressing rod can pass through the central through holes of the base and the box cover, and the pressing rod is disposed adjacent to the hole walls of the central through holes of the base and the box cover.

[0015] An operation method of the above-mentioned robotic arm includes the following steps:

[0016] S1. Close the robotic arm and the monitoring instrument, and make the robotic arm follow the monitoring instrument and fall in the exploration well provided on the planet.

[0017] S2. After the falling action of the robotic arm following the monitoring instrument in the exploration well stops, control the pressing motor to drive the pressing rod to axially expand and contract, so that the pressing rod abuts against the monitoring instrument to lift the base from the surface of the monitoring instrument, and adjust the attitude of the robotic arm to be horizontal.

[0018] S3. After the posture of the robotic arm is adjusted to be horizontal, control the support motor to drive the support rod to expand and contract along its own axis, so that the support rod abuts against the well wall of the detection well to provide a support force for the robotic arm;

[0019] S4. After the support rod abuts against the well wall of the detection well, control the pressing motor to drive the pressing rod to expand and contract along its own axis, so that the pressing rod abuts against the monitoring instrument to adjust the posture of the monitoring instrument to be horizontal, and press and arrange the monitoring instrument at the bottom of the detection well.

[0020] In one embodiment, the robotic arm includes three of the pressing assemblies, and the three pressing assemblies are arranged on the base at intervals; the robotic arm further includes a control board, the control board is arranged on the base and is electrically connected to the support motor and the pressing motor; the robotic arm further includes a third sensor, the third sensor is arranged on the control board, the number of the third sensors is two, and the two third sensors are respectively used for detecting the pitch angle and roll angle of the robotic arm;

[0021] The step S2 of adjusting the posture of the robotic arm to be horizontal includes:

[0022] S211. Determine the step angle of the pressing motor, and set the step length of the pressing rod corresponding to the step angle of the selected pressing motor as l step ;

[0023] S212. Set the length of each pressing rod extending synchronously as L, then the number of steps output by the pressing motor is:

[0024] n C = L / l step

[0025] S213. According to the specifications of the pressing motor and the control board, configure the frequency and duty cycle to generate the pulse waveform of the pressing motor;

[0026] S214. Set the pitch angle of the robotic arm output by the third sensor A1 as α1, and the roll angle of the robotic arm output by the third sensor A2 as α2;

[0027] If |α1| > 2°, then the number of steps output by the pressing motor C1 is:

[0028] n C1 = R*sinα1 / l step

[0029] The number of steps output by the pressing motor C2 and the pressing motor C3 are respectively:

[0030] n C2 = -R*cos60°*sinα1 / lstep ,

[0031] n C3 = n C2

[0032] Wherein, R is the distance between the center of the pressing rod and the center of the robot arm;

[0033] If |α2| > 2°, the number of steps output by the pressing motor C1 is 0;

[0034] The number of steps output by the pressing motor C2 and the pressing motor C3 are respectively:

[0035] n C2 = R * cos30° * sinα2 / l step ,

[0036] n C3 = -n C2

[0037] If |α1| ≤ 2° and |α2| ≤ 2°, it is determined that the posture of the robot arm is horizontal.

[0038] In one embodiment, the robot arm includes two of the support components, and the two support components are spaced apart on the base; the robot arm further includes a control board, the control board is disposed on the base, and is electrically connected to the support motor and the pressing motor; the robot arm further includes a first sensor, the first sensor is disposed on the support rod, the first sensor is used to detect the abutting force of the support rod acting on the wall of the exploration well, the number of the first sensors is two, and the two first sensors respectively correspond to the two support rods one by one;

[0039] The step S3 of controlling the support motor to drive the support rod to axially expand and contract along itself so that the support rod abuts against the wall of the exploration well to provide a support force for the robot arm includes:

[0040] S31. Determine the step angle of the support motor, and set the step angle of the selected support motor as l step ;

[0041] S32. Configure the frequency and duty cycle according to the specifications of the support motor and the control board to generate a pulse waveform of the support motor;

[0042] S33. The two support motors S1 and S2 respectively drive the two support rods SR1 and SR2 to extend outwards, and at the same time monitor the abutting force value V of the support rod SR1 output by the first sensor SS1 SS1 , the abutting force value V of the support rod SR2 output by the first sensor SS2 SS2 ;

[0043] S34. Set the maximum value of the outputs of the first sensors SS1 and SS2 to V when the support rod presses tightly against the wellbore according to engineering experience and the selection of pressure sensors. MAX , set |V SS1 - V SS2 | threshold to V SS ;

[0044] If V SS1 - V SS2 ≥ V SS , then stop driving the support rod SR1 to extend outwards, continue to drive the support rod SR2 to extend outwards until -V SS < V SS1 - V SS2 < V SS ;

[0045] If V SS1 - V SS2 ≤ -V SS , then stop driving the support rod SR2 to extend outwards, continue to drive the support rod SR1 to extend outwards until -V SS < V SS1 - V SS2 < V SS ;

[0046] When V SS1 ≥ V MAX and V SS2 ≥ V MAX , stop driving the support rods SR1 and SR2 to extend outwards. At this time, it is determined that both the support rods SR1 and SR2 press tightly against the wellbore.

[0047] In one embodiment, the step S4 of controlling the pressing motor to drive the pressing rod to axially expand and contract along its own axis so that the pressing rod presses against the monitoring instrument to adjust the attitude of the monitoring instrument to horizontal and tightly arrange the monitoring instrument at the bottom of the exploration well includes:

[0048] S41. Adopt a sliding mode control algorithm to control the pressing motors C1, C2, and C3 to drive the corresponding pressing rods CR1, CR2, and CR3 respectively, push the monitoring instrument downward to continue to fall to the bottom of the well bypassing the obstruction of the wellbore bulge, or couple the monitoring instrument with the bottom soil tightly, and adjust the pressing depth of the pressing rod according to the pitch angle, roll angle, and azimuth angle output by the three fourth sensors Y1, Y2, and Y3 of the monitoring instrument to adjust the attitude of the monitoring instrument to horizontal;

[0049] S42. After the pressing process ends, control the pressing motors C1, C2, and C3 to drive the corresponding pressing rods CR1, CR2, and CR3 to retract to realize separation from the monitoring instrument;

[0050] The sliding mode control algorithm is described by the following first-order dynamic equation:

[0051]

[0052] where the design parameter β > 0 and the system state x ∈ R 1 , both q and p are odd numbers, and q < p < 2q. Solving from the above equation:

[0053]

[0054] Set the time from the initial state x(0) ≠ 0 to x = 0 as t s , t s can be determined by the following equation:

[0055]

[0056] where the origin is a terminal attractor, and the system state x will converge to zero within a finite time t s ;

[0057] The Jacobian determinant of the dynamic equation near the equilibrium point x = 0 is:

[0058]

[0059] Regarding J as the eigenvalue λ of the first-order approximation matrix, then we have:

[0060] J → -∞ when x → 0 +

[0061] At the equilibrium point, the eigenvalue λ tends to negative infinity, where |J| < ∞ is not satisfied, that is, the Lipschitz condition ensuring the uniqueness and existence of the solution of the differential equation at the origin is not satisfied, and J is singular at the point x = 0. When the Lipschitz condition is not satisfied, the system state reaches the equilibrium point in finite time.

[0062] When the robotic arm provided by the present invention is in use, first, the robotic arm and the monitoring instrument are closely attached, and the robotic arm is made to follow the monitoring instrument and fall in the exploration well; after the falling action of the robotic arm following the monitoring instrument in the exploration well stops, control the pressing motor to drive the pressing rod to axially expand and contract along its own axis, so that the pressing rod abuts against the monitoring instrument to lift the base from the surface of the monitoring instrument, and adjust the posture of the robotic arm to be horizontal; after the posture of the robotic arm is adjusted to be horizontal, control the supporting motor to drive the supporting rod to axially expand and contract along its own axis, so that the supporting rod abuts tightly against the well wall of the exploration well to provide a supporting force for the robotic arm; after the supporting rod abuts tightly against the well wall of the exploration well, control the pressing motor to drive the pressing rod to axially expand and contract along its own axis, so that the pressing rod abuts against the monitoring instrument to adjust the posture of the monitoring instrument to be horizontal, and press and arrange the monitoring instrument at the bottom of the exploration well;

[0063] Therefore, by pressing and seating the monitoring instrument, the robotic arm of the present invention can solve problems such as the failure of the layout of the monitoring instrument caused by the protrusion (such as a stone) on the well wall of the exploration well blocking the seating of the monitoring instrument, and the overturning of the monitoring instrument. Even if the exploration well is located on a hard rock base, it can ensure the grounding and stability of the monitoring instrument and adapt to various well conditions. At the same time, by pressing and seating the monitoring instrument with the robotic arm, it can effectively avoid any rotation or swing of the monitoring instrument during the monitoring of the planet, improve the stability of the installation posture of the monitoring instrument, and thus ensure the smooth progress of the detection task of the monitoring instrument. Moreover, the robotic arm of the present invention can also adapt to the soil properties of various planetary surfaces and can work normally in soil conditions with different particle sizes and viscosities, ensuring the tight grounding of the monitoring instrument and being beneficial to improving the signal reception ability of the monitoring instrument. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 Schematic diagram of the combination of the robotic arm and the monitoring instrument provided by the embodiment of the present invention;

[0065] Figure 2 Schematic diagram of the structure of the robotic arm provided by the embodiment of the present invention;

[0066] Figure 3 Cross-sectional view of the robotic arm provided by the embodiment of the present invention;

[0067] Figure 4 Partial structure schematic diagram of the robotic arm provided by the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0068] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. The preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0069] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there may also be an intermediate element. When an element is determined to be "connected to" another element, it can be directly connected to the other element or there may be an intermediate element at the same time.

[0070] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0071] ReferenceFigure 1 , this application provides a robotic arm 100, which is used to tightly press and deploy a monitoring instrument 200 at the bottom of a detection well provided on a planet. Specifically, the monitoring instrument 200 can be a seismograph or other similar instruments like a seismograph.

[0072] Reference Figure 2 , the robotic arm 100 includes a base 110, a support assembly 120, and a pressing assembly 130. The base 110 is used to closely adhere to the monitoring instrument 200; the support assembly 120 is arranged on the base 110. The support assembly 120 includes a support motor 121 and a support rod 122. The support motor 121 is in transmission connection with the support rod 122. The support motor 121 is used to drive the support rod 122 to expand and contract along its own axial direction. The support rod 122 is used to abut against the well wall of the detection well to provide a supporting force for the robotic arm 100; the pressing assembly 130 is arranged on the base 110. The pressing assembly 130 includes a pressing motor 131 and a pressing rod 132. The pressing motor 131 is in transmission connection with the pressing rod 132. The pressing motor 131 is used to drive the pressing rod 132 to expand and contract along its own axial direction. The pressing rod 132 is used to abut against the monitoring instrument 200 to lift the base 110 from the surface of the monitoring instrument 200 and realize the attitude adjustment of the robotic arm 100. The pressing rod 132 is also used to press and adjust the attitude of the monitoring instrument 200.

[0073] When the robotic arm 100 provided by the present invention is in use, first, the robotic arm 100 and the monitoring instrument 200 are closely adhered, and the robotic arm 100 follows the monitoring instrument 200 and falls in the detection well; after the falling action of the robotic arm 100 following the monitoring instrument 200 in the detection well stops, control the pressing motor 131 to drive the pressing rod 132 to expand and contract along its own axial direction, so that the pressing rod 132 abuts against the monitoring instrument 200 to lift the base 110 from the surface of the monitoring instrument 200 and adjust the attitude of the robotic arm 100 to horizontal; after the attitude of the robotic arm 100 is adjusted to horizontal, control the support motor 121 to drive the support rod 122 to expand and contract along its own axial direction, so that the support rod 122 abuts tightly against the well wall of the detection well to provide a supporting force for the robotic arm 100; after the support rod 122 abuts tightly against the well wall of the detection well, control the pressing motor 131 to drive the pressing rod 132 to expand and contract along its own axial direction, so that the pressing rod 132 abuts against the monitoring instrument 200 to adjust the attitude of the monitoring instrument 200 to horizontal and tightly press and deploy the monitoring instrument 200 at the bottom of the detection well;

[0074] Therefore, by pressing and seating the monitoring instrument 200, the robotic arm 100 of the present invention can solve problems such as the failure of the layout platform caused by the protrusion (such as a stone) on the well wall of the exploration well blocking the seating of the monitoring instrument 200 and the tipping over of the monitoring instrument 200. Even if the exploration well is located on a hard rock base, it can ensure the grounding and stability of the monitoring instrument 200 and can adapt to various well conditions. At the same time, by pressing and seating the monitoring instrument 200 with the robotic arm 100, it can effectively prevent the monitoring instrument 200 from rotating or swinging arbitrarily during the monitoring of the planet, improve the stability of the installation attitude of the monitoring instrument 200, and thus ensure the smooth progress of the detection task of the monitoring instrument 200. In addition, the robotic arm 100 of the present invention can also adapt to the soil properties of various planetary surfaces and can work normally in soil conditions with different particle sizes and viscosities, ensuring the tight grounding of the monitoring instrument 200 and being beneficial to improving the signal reception ability of the monitoring instrument 200.

[0075] Reference Figure 2 and Figure 3 , the base 110 can be a box structure. The cross-section of the base 110 is in an annular shape. The base 110 has a central through-hole 113 for passing the power supply and communication cable of the monitoring instrument 200. Specifically, the base 110 includes a base 111 and a box cover 112 that are oppositely arranged. The base 111 and the box cover 112 are coaxially arranged. Both the base 111 and the box cover 112 are provided with a central through-hole 113. The support motor 121 and the pressing motor 131 are both arranged on the base 111. The support motor 121 is fixed on the base 111 through a coupling cone 123. The pressing rod 132 can pass through the central through-holes 113 of the base 111 and the box cover 112, and the pressing rod 132 is arranged adjacent to the hole walls of the central through-holes 113 of the base 111 and the box cover 112.

[0076] To improve the seating and pressing performance of the robotic arm 100, both the support assembly 120 and the pressing assembly 130 include multiple components. The multiple support assemblies 120 are spaced apart on the base 110, and the multiple pressing assemblies 130 are spaced apart on the base 110.

[0077] Reference Figure 4 , preferably, the support assembly 120 includes two components, and the pressing assembly 130 includes three components. The two support assemblies 120 are spaced apart on the base 110, and the three pressing assemblies 130 are spaced apart on the base 110. Specifically, the two support assemblies 120 are symmetrically arranged on both sides of the base 110 along the radial direction of the base 110, and the three pressing assemblies 130 are evenly spaced around the center of the base 110.

[0078] Further, the robotic arm 100 further includes a first sensor disposed on the support rod 122. Specifically, the first sensor is embedded in one end of the support rod 122 (specifically, the end of the support rod 122 that abuts against the well wall of the exploration well). The first sensor is used to detect the abutting force exerted by the support rod 122 on the well wall of the exploration well, so that the operator can reasonably adjust the telescopic amount of the support rod 122 according to the detection result of the first sensor, avoiding the problem of the support rod 122 extending too long or too short.

[0079] Further, the robotic arm 100 further includes a second sensor disposed on the pressing rod 132. Specifically, the second sensor is embedded in one end of the pressing rod 132 (specifically, the end of the pressing rod 132 that abuts against the monitoring instrument 200). The second sensor is used to detect the abutting force exerted by the pressing rod 132 on the monitoring instrument 200, so that the operator can reasonably adjust the telescopic amount of the pressing rod 132 according to the detection result of the second sensor, avoiding the problem of the pressing rod 132 extending too long or too short.

[0080] Reference Figure 2 , further, the robotic arm 100 further includes a control board 140. The control board 140 is disposed on the base 110 and electrically connected to the support motor 121 and the pressing motor 131. The control board 140 is used to control the support motor 121 and the pressing motor 131 to drive the telescopic movements of the support rod 122 and the pressing rod 132 respectively. Specifically, the control board 140 is the core processor of the robotic arm 100, and it is also used to read the attitude information of the robotic arm 100 and the attitude information of the monitoring instrument 200, and complete the function of bottom-seating and pressing of the monitoring instrument 200 by controlling the support motor 121 and the pressing motor 131 to drive the telescopic movements of the support rod 122 and the pressing rod 132 respectively.

[0081] Specifically, the control board 140 is disposed on the base 111 through the first support column 150. The control board 140 is located between the base 111 and the box cover 112. The box cover 112 is connected to the control board 140 through the second support column 160. Specifically, the control board 140, the base 111, and the box cover 112 are arranged in parallel. The first support column 150 and the second support column 160 are coaxially arranged. The length of the first support column 150 is greater than the length of the second support column 160, that is, the distance between the base 111 and the control board 140 is greater than the distance between the box cover 112 and the control board 140.

[0082] The support motor 121 controls the rotation of its power output shaft through the pulse waveform fed back by the control board 140. The power output shaft is connected to the support rod 122, thereby controlling the telescopic amount of the support rod 122 and completing the support function of the robotic arm 100 on the well wall.

[0083] The support assembly 120 further includes a first driver, which is electrically connected to the support motor 121 and the control board 140. Specifically, the pulse waveform generated by the control board 140 is demodulated by the first driver and then output to the support motor 121 through the connection interface. Further, the support assembly 120 further includes a first encoder, which is electrically connected to the support motor 121. The first encoder is used to monitor the accurate position of the support motor 121, provide feedback on the actual position of the support motor 121, and thus adjust the control signal to ensure that the support motor 121 operates as expected.

[0084] Further, the pressing motor 131 controls the rotation of its power output shaft through the pulse waveform fed back by the control board 140. The power output shaft is connected to the pressing rod 132 to control the telescopic amount of the pressing rod 132 and complete the function of sitting and pressing the monitoring instrument 200.

[0085] The pressing assembly 130 further includes a second driver, which is electrically connected to the pressing motor 131 and the control board 140. Specifically, the pulse waveform generated by the control board 140 is demodulated by the second driver and then output to the pressing motor 131 through the connection interface. Further, the pressing assembly 130 further includes a second encoder, which is electrically connected to the pressing motor 131. The second encoder is used to monitor the accurate position of the pressing motor 131, provide feedback on the actual position of the pressing motor 131, and thus adjust the control signal to ensure that the pressing motor 131 operates as expected.

[0086] The robotic arm 100 further includes a third sensor, which is disposed on the control board 140. The third sensor is used to detect the attitude information of the robotic arm 100. Specifically, there are two third sensors, and the two third sensors are respectively used to detect the pitch angle and roll angle of the robotic arm 100.

[0087] Further, a fourth sensor is further disposed on the monitoring instrument 200. The fourth sensor is used to detect the attitude information of the monitoring instrument 200. Specifically, there are three fourth sensors, and the three fourth sensors are respectively used to detect the inclination angles (i.e., pitch angle, roll angle, azimuth angle) of the monitoring instrument 200 in the vertical direction, horizontal east-west direction, and horizontal north-south direction.

[0088] Reference Figure 2 , the robotic arm 100 further includes a wire duct 170, which is disposed on the lid 112. The wire duct 170 is used for the power supply and communication cables of the robotic arm 100 to pass through. To prevent the power supply and communication cables from being entangled with other parts of the robotic arm 100 when they droop, the wire duct 170 is in a bent shape, and the interface of the wire duct 170 faces the outside of the base 110.

[0089] This application also provides an operation method for a robotic arm, including the following steps:

[0090] S1. Press the robotic arm and the monitoring instrument closely, and make the robotic arm follow the monitoring instrument and drop in the exploration well set on the planet.

[0091] S2. After the robotic arm follows the monitoring instrument and stops dropping in the exploration well, control the pressing motor to drive the pressing rod to expand and contract along its own axis, so that the pressing rod abuts against the monitoring instrument to lift the base from the surface of the monitoring instrument, and adjust the posture of the robotic arm to horizontal.

[0092] S3. After the posture of the robotic arm is adjusted to horizontal, control the support motor to drive the support rod to expand and contract along its own axis, so that the support rod abuts tightly against the well wall of the exploration well to provide a support force for the robotic arm.

[0093] S4. After the support rod abuts tightly against the well wall of the exploration well, control the pressing motor to drive the pressing rod to expand and contract along its own axis, so that the pressing rod abuts against the monitoring instrument to adjust the posture of the monitoring instrument to horizontal, and press and arrange the monitoring instrument at the bottom of the exploration well.

[0094] Further, the step S2 of controlling the pressing motor to drive the pressing rod to expand and contract along its own axis, so that the pressing rod abuts against the monitoring instrument to lift the base from the surface of the monitoring instrument, and adjust the posture of the robotic arm to horizontal includes:

[0095] Step S21. After the robotic arm follows the monitoring instrument and stops dropping in the exploration well, the control board 140 controls the three pressing motors C1, C2, and C3 to synchronously drive the corresponding pressing rods CR1, CR2, and CR3 to expand and contract along their own axes, so that each pressing rod synchronously abuts against the monitoring instrument to lift the base from the surface of the monitoring instrument, leaving an operating space for subsequent actions. At the same time, the control board 140 adjusts the height of the pressing rod to lift the robotic arm according to the pitch angle and roll angle of the robotic arm detected by the two third sensors A1 and A2 of the robotic arm, so as to adjust the posture of the robotic arm to horizontal (that is, adjust the inclination angle of the robotic arm to the minimum within the movable range).

[0096] In this embodiment, the robotic arm includes three pressing components, and the three pressing components are arranged on the base at intervals; the robotic arm further includes a control board, the control board is arranged on the base and is electrically connected to the support motor and the pressing motor; the robotic arm further includes a third sensor, the third sensor is arranged on the control board, the number of the third sensors is two, and the two third sensors are respectively used to detect the pitch angle and roll angle of the robotic arm.

[0097] The step S2 of adjusting the posture of the robotic arm to horizontal includes:

[0098] S211. Determine the step angle of the pressing motor, and set the step length of the pressing rod corresponding to the step angle of the selected pressing motor as l step ;

[0099] S212. Set the length of synchronous extension of each pressing rod as L, then the number of steps output by the pressing motor is:

[0100] n C = L / l step

[0101] S213. Configure the frequency and duty cycle according to the specifications of the pressing motor and the control board, and generate the pulse waveform of the pressing motor; Optionally, the pulse waveform can be a PWM waveform.

[0102] S214. Set the pitch angle of the robotic arm output by the third sensor A1 as α1, and the roll angle of the robotic arm output by the third sensor A2 as α2;

[0103] If |α1| > 2°, then the number of steps output by the pressing motor C1 is:

[0104] n C1 = R * sinα1 / l step

[0105] The number of steps output by the pressing motor C2 and the pressing motor C3 are respectively:

[0106] n C2 = -R * cos60° * sinα1 / l step ,

[0107] n C3 = n C2

[0108] wherein, R is the distance between the pressing rod and the center of the robotic arm;

[0109] If |α2| > 2°, then the number of steps output by the pressing motor C1 is 0;

[0110] The number of steps output by the pressing motor C2 and the pressing motor C3 are respectively:

[0111] n C2 = R * cos30° * sinα2 / l step ,

[0112] n C3 = -n C2

[0113] If |α1| ≤ 2° and |α2| ≤ 2°, then it is determined that the posture of the robotic arm is horizontal.

[0114] In an embodiment, the step length l of the pressing rod step = 0.5 mm, the length L of synchronous extension of each pressing rod = 50 mm; the number of steps output by the pressing motor is:

[0115]

[0116] According to the specifications of the pressing motor and the control board, configure a frequency of 5 Hz and a duty cycle of 50% to generate the pulse waveform PWM of the pressing motor;

[0117] Set the pitch angle α1 of the robotic arm output by the third sensor A1 to 5°, the roll angle α2 of the robotic arm output by the third sensor A2 to 1°, and R = 300;

[0118] At this time, if |α1| > 2°, the number of steps output by the pressing motor C1 is:

[0119]

[0120] The number of steps output by the pressing motor C2 and the pressing motor C3 are respectively:

[0121]

[0122] n C3 = n C2 = 26

[0123] At this time, if |α2| ≤ 2°, it is determined that the Y-axis direction of the robotic arm is horizontal.

[0124] Furthermore, the robotic arm includes two support components, which are spaced apart on the base; the robotic arm further includes a control board, which is arranged on the base and is electrically connected to the support motor and the pressing motor; the robotic arm further includes a first sensor, which is arranged on the support rod, and the first sensor is used to detect the abutting force of the support rod acting on the well wall of the exploration well. The number of the first sensors is two, and the two first sensors respectively correspond to the two support rods one by one;

[0125] The step S3 of controlling the support motor to drive the support rod to axially extend and retract along itself so that the support rod abuts against the well wall of the exploration well to provide a support force for the robotic arm includes:

[0126] S31. Determine the step angle of the support motor, and set the step angle of the selected support motor to l step ;

[0127] S32. According to the specifications of the support motor and the control board, configure the frequency and duty cycle to generate the pulse waveform of the support motor; optionally, the pulse waveform can be a PWM waveform.

[0128] S33. The two support motors S1 and S2 respectively drive the two support rods SR1 and SR2 to extend outwards, and at the same time monitor the abutting force value V of the support rod SR1 output by the first sensor SS1 SS1 and the abutting force value V of the support rod SR2 output by the first sensor SS2SS2 ;

[0129] S34. Set the maximum value of the outputs of the first sensors SS1 and SS2 to V when the support rod presses tightly against the wellbore according to engineering experience and the selection of the pressure sensor. MAX , set |V SS1 - V SS2 | threshold to V SS ;

[0130] If V SS1 - V SS2 ≥ V SS , then stop driving the support rod SR1 to extend outwards, continue to drive the support rod SR2 to extend outwards until -V SS < V SS1 - V SS2 < V SS ;

[0131] If V SS1 - V SS2 ≤ -V SS , then stop driving the support rod SR2 to extend outwards, continue to drive the support rod SR1 to extend outwards until -V SS < V SS1 - V SS2 < V SS ;

[0132] When V SS1 ≥ V MAX and V SS2 ≥ V MAX , stop driving the support rods SR1 and SR2 to extend outwards. At this time, it is determined that both the support rods SR1 and SR2 press tightly against the wellbore.

[0133] In an embodiment, set the maximum value V MAX = 5V of the outputs of the first sensors SS1 and SS2, and set the threshold V SS1 - V SS2 | of |V SS = 0.5V;

[0134] If V SS1 - V SS2 ≥ 0.5, then stop driving the support rod SR1 to extend outwards, continue to drive the support rod SR2 to extend outwards until -0.5 < V SS1 - V SS2 < 0.5;

[0135] When V SS1 ≥ 5V and V SS2 ≥ 5V, stop driving the support rods SR1 and SR2 to extend outwards. At this time, it is determined that both the support rods SR1 and SR2 press tightly against the wellbore.

[0136] Further, the step S4 of controlling the pressing motor to drive the pressing rod to axially extend and retract along its own axis, so that the pressing rod abuts against the monitoring instrument to adjust the attitude of the monitoring instrument to horizontal and tightly arrange the monitoring instrument at the bottom of the exploration well includes:

[0137] S41. Adopt a sliding mode control algorithm to control the pressing motors C1, C2, and C3 to drive the corresponding pressing rods CR1, CR2, and CR3 respectively, and push the monitoring instrument downward to continue falling to the bottom of the well bypassing the obstruction of the well wall bulge, or tightly couple the monitoring instrument with the bottom soil, and adjust the pressing depth of the pressing rod according to the pitch angle, roll angle, and azimuth angle output by the three fourth sensors Y1, Y2, and Y3 of the monitoring instrument, so as to adjust the attitude of the monitoring instrument to horizontal (that is, adjust the tilt angle of the monitoring instrument to the minimum within the movable range);

[0138] The sliding mode control algorithm is described by the following first-order dynamic equation:

[0139]

[0140] In the formula, the design parameter β>0, the system state x∈R 1 , both q and p are odd numbers, and q<p<2q. Solved from the above formula:

[0141]

[0142] Set the time from the initial state x(0)≠0 to x = 0 as t s , t s Can be determined by the following formula:

[0143]

[0144] Among them, the origin is a terminal attractor, and the system state x will converge to zero within a finite time t s ;

[0145] The Jacobian determinant of the dynamic equation near the equilibrium point x = 0 is:

[0146]

[0147] Regard J as the eigenvalue λ of the first-order approximation matrix, then there is:

[0148] J→-∞ when x→0 +

[0149] At the equilibrium point, the eigenvalue λ tends to negative infinity, where |J| < ∞ is not satisfied, that is, the Lipschitz condition for ensuring the uniqueness and existence of the solution of the differential equation at the origin is not satisfied, and J is singular at x = 0. When the Lipschitz condition is not satisfied, the system state reaches the equilibrium point in finite time;

[0150] S42. After the pressing process ends, control the pressing motors C1, C2, and C3 to drive the corresponding pressing rods CR1, CR2, and CR3 to retract respectively, so as to achieve separation from the monitoring instrument.

[0151] Optionally, step S4 includes:

[0152] S411. Set the target pitch angle and roll angle of the monitoring instrument to zero, that is, set the attitude of the monitoring instrument to horizontal;

[0153] TARGET_PITCH_ANGLE 0.0,

[0154] TARGET_ROLL_ANGLE 0.0

[0155] S412. Set the proportional parameter of the sliding mode control algorithm to control the response speed and stability of the sliding mode controller;

[0156] #define K1 0.1

[0157] #define K2 0.1

[0158] #define K3 0.2

[0159] S413. Define the sliding mode function to convert the error into the direction of the control input;

[0160] double s_function(double error){

[0161] return error >= 0? 1 : -1;

[0162] }

[0163] This sliding mode function returns 1 or -1 according to the positive or negative of the input parameter (i.e., the error);

[0164] S414. Define the control function of the pressing motor;

[0165] void stepper_control(double length1,double length2,double length3){

[0166] set_stepper1_position(length1);

[0167] set_stepper2_position(length2);

[0168] set_stepper3_position(length3);

[0169] }

[0170] S415. Define the monitoring of three second sensors CS1, CS2, and CS3;

[0171]

[0172] S416. In the main function of the sliding mode control algorithm, read the pitch angle and roll angle output by two fourth sensors Y1 and Y2 of the monitoring instrument;

[0173] int main(){

[0174] pitch_angle = Y1;

[0175] roll_angle = Y2;

[0176] S417. Calculate the error between the actual attitude angle and the target attitude angle of the monitoring instrument;

[0177] while(1){

[0178] double pitch_error = TARGET_PITCH_ANGLE - pitch_angle;

[0179] double roll_error = TARGET_ROLL_ANGLE - roll_angle;

[0180] S418. Apply the sliding mode control algorithm to calculate the control quantity according to the attitude angle error and control parameters, where the negative sign represents the control direction;

[0181] double u1 = -K1 * s_function(pitch_error);

[0182] double u2 = -K2 * s_function(roll_error);

[0183] double u3 = -K3 * s_function(pitch_error);

[0184] S419. Send the calculated control quantity to the pressing motors C1, C2, and C3 to control the telescopic lengths of the corresponding pressing rods CR1, CR2, and CR3;

[0185] stepper_control(u1,u2,u3);

[0186] S420. Check whether the pressure values output by the three second sensors CS1, CS2, and CS3 exceed the threshold;

[0187] if(check_pressure_sensors()){

[0188] break;

[0189] }

[0190] S421. If the pressure value output by one of the second sensors exceeds the threshold, update the pitch angle and roll angle of the robotic arm, and re - execute step S412;

[0191] pitch_angle+=u1;

[0192] roll_angle+=u2;

[0193] S422. When the error of the attitude angle of the monitoring instrument is less than the preset threshold, the process ends and exits the loop. At this time, it is determined that the attitude of the monitoring instrument is horizontal;

[0194] if(fabs(pitch_error)<0.01&&fabs(roll_error)<0.01){

[0195] break;

[0196] }

[0197] S423. Control the three pressing rods CR1, CR2, and CR3 to extend outward synchronously, and at the same time monitor the pressure output values pressure_sensor1, pressure_sensor2, pressure_sensor3 of the three second sensors CS1, CS2, and CS3;

[0198] S424. When the pressure output values of the three second sensors CS1, CS2, and CS3 are all greater than or equal to the pressure threshold, the three pressing motors C1, C2, and C3 stop operating, and the robotic arm presses and arranges the monitoring instrument at the bottom of the exploration well;

[0199] pressure_sensor1>=PRESSURE_THRESHOLD||

[0200] pressure_sensor2 >= PRESSURE_THRESHOLD ||

[0201] pressure_sensor3 >= PRESSURE_THRESHOLD;

[0202] After the pressing process ends, control the pressing motors C1, C2, and C3 to drive the corresponding pressing rods CR1, CR2, and CR3 to retract respectively, so as to realize the separation from the monitoring instrument, and the bottom landing and pressing operations of the monitoring instrument are completed.

[0203] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be determined that it is within the scope described in this specification.

[0204] The above embodiments only represent the preferred implementation modes of the present invention. The description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A robotic arm for tightly arranging a monitoring instrument at the bottom of a detection well provided on a planet, characterized in that, The robotic arm includes: A base for closely adhering to the monitoring instrument; A support assembly disposed on the base. The support assembly includes a support motor and a support rod. The support motor is in transmission connection with the support rod. The support motor is used to drive the support rod to axially extend and retract along its own axis. The support rod is used to press against the wellbore wall of the exploration well to provide a supporting force for the robotic arm; and A pressing assembly disposed on the base. The pressing assembly includes a pressing motor and a pressing rod. The pressing motor is in transmission connection with the pressing rod. The pressing motor is used to drive the pressing rod to axially extend and retract along its own axis. The pressing rod is used to press against the monitoring instrument to lift the base from the surface of the monitoring instrument and realize the attitude adjustment of the robotic arm. The pressing rod is also used to press and adjust the attitude of the monitoring instrument.

2. The robotic arm according to claim 1, characterized in that, Both the support assembly and the pressing assembly include a plurality of them. The plurality of support assemblies are spaced apart and disposed on the base. The plurality of pressing assemblies are spaced apart and disposed on the base.

3. The robotic arm according to claim 1, wherein The robotic arm further includes a first sensor and / or a second sensor. The first sensor is disposed on the support rod. The first sensor is used to detect the abutting force of the support rod acting on the wellbore wall of the exploration well. The second sensor is disposed on the pressing rod. The second sensor is used to detect the abutting force of the pressing rod acting on the monitoring instrument.

4. The robotic arm according to claim 1, characterized in that, The robotic arm further includes a control board. The control board is disposed on the base and is electrically connected to the support motor and the pressing motor.

5. The robotic arm according to claim 4, wherein, The robotic arm further includes a third sensor. The third sensor is disposed on the control board. The third sensor is used to detect the attitude information of the robotic arm.

6. The robotic arm according to claim 1, characterized in that, The base is of a box structure. The cross-section of the base is in a circular ring shape. The base has a central through hole for the power supply and communication cable of the monitoring instrument to pass through. The base includes a base and a box cover disposed opposite to each other. The base and the box cover are coaxially arranged. Both the base and the box cover are provided with the central through hole. The support motor and the pressing motor are both disposed on the base.

7. The robotic arm according to claim 6, characterized in that, The support motor is fixed to the base through a coupling cone. The pressing rod can pass through the central through holes of the base and the box cover, and the pressing rod is disposed adjacent to the hole walls of the central through holes of the base and the box cover.

8. An operating method of the robotic arm according to any one of claims 1 to 7, characterized in that, Including the following steps: S1. Close the robotic arm and the monitoring instrument, and make the robotic arm follow the monitoring instrument and fall in the exploration well provided on the planet; S2. After the falling action of the robotic arm following the monitoring instrument in the exploration well stops, control the pressing motor to drive the pressing rod to axially extend and retract along its own axis, so that the pressing rod presses against the monitoring instrument to lift the base from the surface of the monitoring instrument and adjust the attitude of the robotic arm to be horizontal; S3. After the attitude of the robotic arm is adjusted to be horizontal, control the support motor to drive the support rod to axially extend and retract along its own axis, so that the support rod presses against the wellbore wall of the exploration well to provide a supporting force for the robotic arm. S4. After the support rod abuts against the well wall of the detection well, control the pressing motor to drive the pressing rod to axially expand and contract along its own axis, so that the pressing rod abuts against the monitoring instrument to adjust the attitude of the monitoring instrument to horizontal, and press and arrange the monitoring instrument at the bottom of the detection well.

9. The operating method of the robotic arm according to claim 8, wherein, The robotic arm includes three of the pressing assemblies, and the three pressing assemblies are spaced apart on the base; the robotic arm further includes a control board, which is arranged on the base and electrically connected to the support motor and the pressing motor; the robotic arm further includes a third sensor, which is arranged on the control board, and the number of the third sensors is two, and the two third sensors are respectively used for detecting the pitch angle and roll angle of the robotic arm; The step S2 of adjusting the attitude of the robotic arm to horizontal includes: S211. Determine the step angle of the pressing motor, and set the step length of the pressing rod corresponding to the step angle of the selected pressing motor as l step ; S212. Set the length of the synchronous extension of each pressing rod to be L, then the number of steps output by the pressing motor is: n C = L / l step S213. According to the specifications of the pressing motor and the control board, configure the frequency and duty cycle to generate the pulse waveform of the pressing motor; S214. Set the pitch angle of the robotic arm output by the third sensor A1 to be α1, and the roll angle of the robotic arm output by the third sensor A2 to be α2; If |α1| > 2°, then the number of steps output by the pressing motor C1 is: n c1 = R * sinα1 / l step The number of steps output by the pressing motors C2 and C3 are respectively: n C2 = -R * cos60° * sinα1 / l step , n C3 = n C2 where R is the distance between the pressing rod and the center of the robotic arm; If |α2| > 2°, then the number of steps output by the pressing motor C1 is 0; The number of steps output by the pressing motors C2 and C3 are respectively: n C2 = R * L cos 30° * sin α2 / l step , n C3 = -n C2 If |α1| ≤ 2° and |α2| ≤ 2°, then it is determined that the attitude of the robotic arm is horizontal.

10. The operating method of the robotic arm according to claim 8, characterized in that, The robotic arm includes two of the support assemblies, and the two support assemblies are spaced apart on the base; the robotic arm further includes a control board, which is arranged on the base and electrically connected to the support motor and the pressing motor; the robotic arm further includes a first sensor, which is arranged on the support rod, and the first sensor is used for detecting the abutting force of the support rod on the well wall of the detection well, and the number of the first sensors is two, and the two first sensors respectively correspond to the two support rods one by one; The step S3 of controlling the support motor to drive the support rod to axially expand and contract along its own axis, so that the support rod abuts against the well wall of the detection well to provide a supporting force for the robotic arm includes: S31. Determine the step angle of the support motor, and set the step angle of the selected support motor to l step2 ; S32. According to the specifications of the support motor and the control board, configure the frequency and duty cycle to generate the pulse waveform of the support motor; S33. The two support motors S1 and S2 drive the two support rods SR1 and SR2 to extend outwards respectively, and at the same time monitor the abutting force value V of the support rod SR1 output by the first sensor SS1 SS1 and the abutting force value V of the support rod SR2 output by the first sensor SS2 SS2 ; S34. According to engineering experience and the selection of pressure sensors, when the support rod is tightened against the wellbore wall, the maximum values output by the first sensors SS1 and SS2 are set to V MAX , set |V SS1 -V SS2 | threshold is V SS ; If V SS1 -V SS2 ≥V SS , stop driving the support rod SR1 to extend outwards, and continue to drive the support rod SR2 to extend outwards until -V SS <V SS1 -V SS2 <V SS ; If V SS1 -V SS2 ≤ -V SS , stop driving the support rod SR2 to extend outwards, and continue to drive the support rod SR1 to extend outwards until -V SS < V SS1 -V SS2 < V SS ; When V SS1 ≥ V MAX and V SS2 ≥ V MAX , stop driving the support rods SR1 and SR2 to extend outwards. At this time, it is determined that both the support rods SR1 and SR2 are tightly pressed against the wellbore wall.

11. The operating method of the robotic arm according to claim 8, characterized in that, The step S4 of controlling the pressing motor to drive the pressing rod to axially expand and contract along its own axis, so that the pressing rod abuts against the monitoring instrument to adjust the attitude of the monitoring instrument to horizontal, and press and arrange the monitoring instrument at the bottom of the detection well includes: S41. Adopt the sliding mode control algorithm to control the pressing motors C1, C2, and C3 to drive the corresponding pressing rods CR1, CR2, and CR3 respectively, push the monitoring instrument downward to bypass the obstruction of the wellbore bulge and continue to fall to the bottom of the well, or press and couple the monitoring instrument with the bottom soil of the well, and adjust the pressing depth of the pressing rod according to the pitch angle, roll angle, and azimuth angle output by the three fourth sensors Y1, Y2, and Y3 of the monitoring instrument, so as to adjust the attitude of the monitoring instrument to horizontal; The sliding mode control algorithm is described by the following first-order dynamic equation: where the design parameter β > 0 and the system state x ∈ R 1 , both q and p are odd numbers, and q < p < 2q. Solving from the above equation gives: Set the time from the initial state x(0)≠0 to x = 0 as t s ,t s which can be determined by the following formula: Among them, the origin is an attractor of a terminal, and the system state x will converge to zero within a finite time t s ; The Jacobian determinant of the dynamic equation near the equilibrium point x = 0 is: Regard J as the eigenvalue λ of the first-order approximation matrix, so there is: J → -∞ when x → 0 + At the equilibrium point, the eigenvalue λ tends to negative infinity, and here |J| < ∞ is not satisfied, that is, the Lipschitz condition for ensuring the uniqueness and existence of the solution of the differential equation at the origin is not satisfied, and J is singular at the point x = 0. When the Lipschitz condition is not satisfied, the system state reaches the equilibrium point in a finite time. S42. After the pressing process is completed, control the pressing motors C1, C2, and C3 to drive the corresponding pressing rods CR1, CR2, and CR3 to retract respectively to realize the separation from the monitoring instrument.

Images