A pose detection and control device and method for a multi-joint arm
By combining a laser rangefinder and an adjustable deflector with a photoelectric sensor, the problem of accuracy in end-effector pose detection of multi-joint booms was solved, enabling rapid and precise pose control and improving the accuracy of construction operations.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA RAILWAY CONSTR HEAVY IND
- Filing Date
- 2023-05-22
- Publication Date
- 2026-05-12
AI Technical Summary
Existing technologies struggle to accurately determine the actual positional parameters of the end effector of multi-joint flexible booms, especially when flexural deformation accumulates, which affects the accuracy of construction operations.
By using a laser rangefinder and an adjustable deflector, combined with a photoelectric sensor, the actual pose of the boom end is detected by detecting the direction of deflection and making fine adjustments to the deflection angle. The actual pose is then adjusted by the control system to match the theoretical pose.
The system can quickly and accurately detect the actual position and orientation of the end of a multi-joint boom, enabling precise position and orientation control under the cumulative effect of flexible deformation, and improving the accuracy of construction operations.
Smart Images
Figure CN116652942B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of precision monitoring and control technology for the movement of multi-joint flexible booms, and particularly to a device and method for position detection and control of multi-joint booms. Background Technology
[0002] Multi-joint flexible booms are widely used in construction machinery. A multi-joint flexible boom uses multiple articulated booms that rotate and extend relative to each other to move the actuator mounted at the boom end to the working position at a set angle and direction for construction operations. Due to the weight of the actuator and the working reaction force (load), the boom will undergo deflection deformation, resulting in errors between the actual position and the theoretical calculation results, affecting the accuracy of construction operations.
[0003] Currently, the deflection problem is generally solved by detecting the actual tilt angle of each arm and comparing it with theoretical values, then substituting compensation parameters into the control model for correction. However, this method has significant errors. Even with accurate measurements of the tilt angle and extension distance at each arm joint, the accurate pose parameters of the end effector of the multi-joint flexible boom are still difficult to determine due to the accumulation of flexible deformation. (Reference) Figure 1 , Figure 1 The solid line represents the theoretical pose, and the double-dotted line represents the actual pose under load. It can be seen that there is still a deviation between the actual pose and the theoretical pose under load. Summary of the Invention
[0004] (a) Technical problems to be solved
[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a pose detection device, control device and method for a multi-joint boom, which solves the technical problem that, due to the accumulation of flexible deformation, it is still difficult to determine the accurate pose parameters of the end of a multi-joint flexible boom even if the tilt angle and extension distance at each boom joint are accurately measured.
[0006] (II) Technical Solution
[0007] To achieve the above objectives, the main technical solutions adopted by the present invention include:
[0008] In a first aspect, embodiments of the present invention provide a pose detection device for a multi-joint boom, the multi-joint boom including multiple boom arms, each boom arm being rotatable relative to the end of the previous boom arm; including a laser rangefinder and an adjustable deflection mirror;
[0009] The laser rangefinder is installed at the end of the boom arm, and the laser ranging direction is pointed towards the rotation center of the root of the boom arm;
[0010] The adjustable deflector is installed at the center of rotation at the base of the boom arm and is coaxial with the center of rotation.
[0011] The pose detection device for a multi-joint boom proposed in this invention uses an adjustable angle reflector, a photoelectric sensor, and a laser rangefinder to detect the actual pose of the end of the boom arm. It can quickly and accurately detect the actual pose of the end of the boom arm and measure the true effect and precise position of the cumulative flexural deformation on the pose.
[0012] Optionally, the end of the boom arm is equipped with a pin or actuator for rotating the next boom arm section.
[0013] Optionally, the boom can be extended or slid along its length or be fixed in length.
[0014] Optionally, it also includes photoelectric sensors, with at least two photoelectric sensors. The at least two photoelectric sensors are respectively arranged on both radial sides of the laser rangefinder perpendicular to the laser ranging direction and facing the rotation center, and are used to determine the deflection deformation direction of the boom arm.
[0015] Optionally, the two radial sides perpendicular to the laser ranging direction are one side of the load acting direction at the end of the boom arm and the corresponding opposite side.
[0016] Optionally, it also includes a control system, which is electrically connected to the laser rangefinder, the photoelectric sensor, and the adjustable deflection mirror, and is used for:
[0017] Optionally, the boom arm is driven to rotate at a preset angle. Based on the deflection direction of the boom arm obtained by the photoelectric sensor, the adjustable deflection mirror is controlled to make a fine adjustment in the opposite direction of the deflection direction so that the laser rangefinder can receive the measurement beam emitted by itself.
[0018] Optionally, when the laser rangefinder receives the measurement beam it emits, it reads the angle information of the current position of the adjustable deflection mirror and the distance information measured by the laser rangefinder; thus obtaining the actual pose of the end of the boom arm.
[0019] Secondly, embodiments of the present invention provide a pose control device for a multi-joint boom, including the aforementioned pose control device for a multi-joint boom. The control system is further configured to compare the actual pose of the boom arm end with the theoretical pose, and adjust the rotation angle and length of the boom arm according to the difference between the actual pose and the theoretical pose, so that the actual pose of the boom arm coincides with the theoretical pose.
[0020] Optionally, the theoretical pose includes the length of the boom arm and the rotation angle of the boom arm relative to the previous boom arm.
[0021] Thirdly, embodiments of the present invention also provide a control method for the above-mentioned multi-joint boom posture control device, comprising the following steps:
[0022] Reset the adjustable deflector, turn on the laser rangefinder, and adjust the laser rangefinder to receive the measurement beam emitted by itself. Read the angle information of the initial position of the adjustable deflector and the initial distance information measured by the laser rangefinder to obtain the initial pose of the boom arm end.
[0023] The boom arm rotates at a preset angle and / or extends to a preset length based on the initial position. According to the deflection direction of the boom arm obtained by the photoelectric sensor, the adjustable deflection mirror is controlled to make fine-tuning of the deflection angle in the opposite direction of the deflection direction so that the laser rangefinder can receive the measurement beam emitted by itself again.
[0024] When the laser rangefinder receives the measurement beam it emitted again, it reads the angle information of the current position of the adjustable deflector and the distance information measured by the laser rangefinder to obtain the actual pose of the end of the boom arm.
[0025] The actual pose of the boom end is compared with the theoretical pose. Based on the difference between the actual and theoretical poses, the rotation angle and length of the boom are adjusted to make the actual pose of the boom coincide with the theoretical pose.
[0026] Optionally, the steps of obtaining the actual pose of the boom arm end and adjusting the rotation angle and length of the boom arm according to the difference are repeated multiple times until the actual pose of the boom arm coincides with the theoretical pose; wherein, before each iteration, the adjustable deflection mirror is reset.
[0027] (III) Beneficial Effects
[0028] The beneficial effects of this invention are as follows: The pose detection and control device and method for the multi-joint boom of this invention, by employing an adjustable-angle reflector, a photoelectric sensor, and a laser rangefinder to detect the actual pose of the boom arm's end, can quickly and accurately detect the actual pose of the boom arm's end compared to existing technologies. It can also measure the cumulative effect of flexible deformation on the pose and the precise positional difference of the deformation. This control device and method can continuously adjust the actual pose to approach the theoretical pose, thereby controlling the end of the boom arm to reach the predetermined target position, with rapid response and accurate results. Attached Figure Description
[0029] Figure 1 This is a comparative diagram of the theoretical pose and the actual pose under load in the prior art.
[0030] Figure 2 This is a schematic diagram of the structure of the multi-joint boom pose detection device and control device in an embodiment of the present invention (the boom arm is in the initial pose);
[0031] Figure 3 This is a schematic diagram of the actual pose of the multi-joint boom pose detection device and control device in an embodiment of the present invention during the flexible deformation of the boom arm.
[0032] Figure 4 This is a schematic diagram showing the actual pose of the multi-joint boom posture control device in an embodiment of the present invention coinciding with the theoretical pose after adjustment.
[0033] [Explanation of Labels in the Attached Image]
[0034] 1. Laser rangefinder; 2. Photoelectric sensor; 3. Adjustable deflection mirror; 4. Boom outrigger; 5. Control system. Detailed Implementation
[0035] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.
[0036] The pose detection device, control device, and method for multi-joint booms proposed in this invention overcome the technical problem that, due to the accumulation of flexible deformation, even if the tilt angle and telescopic distance at each boom joint are accurately measured, it is still difficult to determine the accurate pose parameters of the end of the multi-joint flexible boom. By using a laser rangefinder and an adjustable deflection mirror, the precise value of the actual pose is determined. The direction of deflection deformation is detected by a photoelectric sensor, and the actual pose of the boom arm is iteratively controlled to approach the theoretical pose and eventually coincide with the theoretical pose based on the compensation in the opposite direction, so as to achieve precise pose control and realize rapid and accurate pose detection and control.
[0037] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention can be understood more clearly and thoroughly, and that the scope of the present invention can be fully conveyed to those skilled in the art.
[0038] Example 1:
[0039] See Figure 1The multi-joint boom includes multiple boom arms 4, each of which can rotate relative to the end of the previous boom arm 4. In this embodiment, the multi-joint boom is a multi-joint flexible boom. The end of the boom arm 4 is equipped with a pin or actuator for driving the rotation of the next boom arm 4. The boom arm 4 can be extended, slid, or fixed in length in the longitudinal direction.
[0040] See Figure 2 The pose detection device for a multi-joint boom according to an embodiment of the present invention includes a laser rangefinder 1, two photoelectric sensors 2, and an adjustable deflection mirror 3. The laser rangefinder 1 is located at the end of the boom arm 4, and the laser ranging direction points towards the rotation center at the root of the boom arm 4. The adjustable deflection mirror 3 is installed at the rotation center at the root of the boom arm 4 and is coaxial with the rotation center. At least two photoelectric sensors 2 are provided, respectively arranged on both radial sides of the laser rangefinder 1 perpendicular to the laser ranging direction, facing the boom arm 4, and used to determine the deflection deformation direction of the boom arm 4. The radial sides perpendicular to the laser ranging direction are one side of the load acting direction at the end of the boom arm 4 and the corresponding opposite side, such as the upper and lower sides.
[0041] In implementation, the pose detection device for the multi-joint boom of this invention further includes a control system 5. The control system 5 is electrically connected to the laser rangefinder 1, the photoelectric sensor 2, and the adjustable deflection mirror 3, and is used to: drive the boom arm 4 to rotate at a preset angle; control the adjustable deflection mirror 3 to make fine-tuning angles in the opposite direction of the deflection deformation direction according to the deflection deformation direction collected by the photoelectric sensor 2, so that the laser rangefinder 1 receives the measurement beam emitted by itself; when the laser rangefinder 1 receives the measurement beam emitted by itself, read the angle information of the current position of the adjustable deflection mirror 3 and the distance information measured by the laser rangefinder 1; and obtain the actual pose of the end of the boom arm 4. Thus, the accurate pose of the end of the boom arm 4 is measured.
[0042] See Figure 2 In the initial pose, the adjustable angle reflector 3 is aligned with the initial rotation angle of the boom arm 4 (resetting the adjustable angle reflector 3). The laser rangefinder 1 can then receive the measurement beam reflected from its own emission through the adjustable angle reflector 3. See also... Figure 3When the boom arm 4 performs an action, its position changes; and under the load, the boom arm undergoes deflection deformation. The combination of these two factors prevents the measurement beam reflected by the adjustable angle reflector 3 from reaching the laser rangefinder 1, and the laser rangefinder 1 cannot receive its own measurement beam. At this time, any photoelectric sensor 2 can detect the direction and position of the reflected measurement beam, thereby detecting the direction of the deflection deformation of the boom arm 4. It controls the adjustable angle reflector 3 to make a fine-tuning angle in the opposite direction of the deflection deformation, so that the laser rangefinder 1 can receive its own measurement beam again. The angle information of the current position of the adjustable angle reflector 3 and the distance information measured by the laser rangefinder 1 are read to obtain the actual position of the end of the boom arm 4.
[0043] Example 2:
[0044] The pose control device for a multi-joint boom according to this invention includes the pose control device for a multi-joint boom as described in Embodiment 1, and further includes a control system 5. The control system 5 is used to compare the actual pose of the end of the boom arm 4 with the theoretical pose, and adjust the rotation angle and length of the boom arm 4 according to the difference between the actual pose and the theoretical pose, so that the actual pose of the boom arm 4 coincides with the theoretical pose. The theoretical pose includes the length of the boom arm 4 and the rotation angle of the boom arm 4 relative to the previous boom arm 4.
[0045] See Figure 2 In the initial pose, the adjustable angle reflector 3 is aligned with the initial rotation angle of the boom arm 4 (resetting the adjustable angle reflector 3). The laser rangefinder 1 can then receive the measurement beam reflected from its own emission through the adjustable angle reflector 3. See also... Figure 3 When the boom arm 4 performs its action, its position changes; and under the load, the boom arm undergoes deflection deformation. The combination of these two factors causes the measurement beam reflected by the adjustable angle reflector 3 to fail to reach the laser rangefinder 1, and the laser rangefinder 1 to fail to receive its own measurement beam (the reflection point of the measurement beam of the laser rangefinder 1 shifts, and the signal of the laser rangefinder 1 disappears). At this time, any photoelectric sensor 2 can detect the direction of the reflected measurement beam (the upper photoelectric sensor 2 emits a signal after detecting the light spot), thereby detecting the direction of the deflection deformation of the boom arm 4. The adjustable deflector 3 is finely adjusted to face the opposite direction of the deflection deformation, so that the laser rangefinder 1 can receive its own emitted measurement beam again; the angle information of the current position of the adjustable deflector 3 and the distance information measured by the laser rangefinder 1 are read to obtain the actual pose of the end of the boom arm 4; the difference between the actual pose and the theoretical pose is calculated, and the rotation angle and length of the boom arm 4 are adjusted according to the difference to make the actual pose of the boom arm 4 coincide with the theoretical pose (see...). Figure 4 ).
[0046] Example 3:
[0047] The control method of the pose control device for the multi-joint boom according to an embodiment of the present invention includes the following steps:
[0048] S1: Reset the adjustable deflector 3, turn on the laser rangefinder 1, and adjust the laser rangefinder 1 to receive the measurement beam emitted by itself. Read the angle information of the initial position of the adjustable deflector 3 and the initial distance information measured by the laser rangefinder 1 to obtain the initial pose of the end of the boom arm 4; see Figure 2 .
[0049] S2: Drive the boom arm 4 to rotate at a preset angle and / or extend to a preset length based on the initial pose, according to the deflection deformation direction of the boom arm 4 obtained by the photoelectric sensor 2 (see...). Figure 3 When the boom arm undergoes flexural deformation under load, the reflection point of the measuring beam of the laser rangefinder 1 shifts, and the signal of the laser rangefinder 1 disappears. At this time, the laser beam (measuring beam) emitted by the laser rangefinder 1 is deflected after being reflected by the adjustable deflection mirror 3, and sweeps across the photoelectric sensor 2 on one side (for example, the photoelectric sensor 2 above detects the light spot and emits a signal). This controls the adjustable deflection mirror 3 to make a fine adjustment of the deflection angle in the opposite direction of the deflection deformation, so that the laser rangefinder 1 can receive the measuring beam it emits again.
[0050] S3: When the laser rangefinder 1 receives the measurement beam it emitted again, it reads the angle information of the current position of the adjustable deflector 3 and the distance information measured by the laser rangefinder 1 to obtain the actual pose of the end of the boom arm 4; see Figure 4 .
[0051] S4: Compare the actual pose of the end of the boom arm 4 with the theoretical pose. Based on the difference between the actual pose and the theoretical pose, adjust the rotation angle and length of the boom arm 4 to make the actual pose of the boom arm 4 coincide with the theoretical pose.
[0052] In step S4, the process of obtaining the actual pose of the end of the boom arm 4 and adjusting the rotation angle and length of the boom arm 4 based on the difference is repeated multiple times until the actual pose of the boom arm 4 coincides with the theoretical pose. Before each iteration, the adjustable deflection mirror 3 is reset.
[0053] The adjustable deflector 3 rotates in the opposite direction to the detected light signal, causing the reflection point of the laser rangefinder 1's measuring beam to shift towards the actual center of the boom arm 4's end. The laser rangefinder 1 stops after re-detecting the signal (its own measuring beam). At this point, the angle of the adjustable deflector 3 is the true deflection angle of the actual center of the boom arm 4's end. The distance detected by the laser rangefinder 1, plus the distance between the adjustable deflector 3 and the rotation axis, represents the true distance between the actual center of the boom arm 4's end and the rotation axis.
[0054] In summary, the pose detection device, control device, and method for the multi-joint boom of the present invention can detect the actual pose of the end of the boom arm 4. It features a simple structure, rapid response, and intuitive data. The measurement results can be directly used as motion control target values, providing accurate results and guiding the boom motion drive mechanism.
[0055] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.
[0056] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0057] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," or "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "beneath" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0058] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0059] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.
Claims
1. A pose detection device for a multi-joint boom, the multi-joint boom comprising multiple boom arms (4), each boom arm (4) being rotatable relative to the end of the previous boom arm (4); characterized in that, Includes a laser rangefinder (1) and an adjustable deflector (3); The laser rangefinder (1) is located at the end of the boom arm (4), and the laser ranging direction is directed towards the rotation center of the root of the boom arm (4). The adjustable angle reflector (3) is installed at the rotation center of the root of the boom arm (4) and is coaxial with the rotation center; It also includes photoelectric sensors (2) and a control system (5). The number of photoelectric sensors (2) is at least two. The at least two photoelectric sensors (2) are respectively arranged on both radial sides of the laser rangefinder (1) perpendicular to the laser ranging direction and facing the rotation center, and are used to determine the deflection deformation direction of the boom arm (4). The control system (5) is electrically connected to the laser rangefinder (1), the photoelectric sensor (2), and the adjustable deflection mirror (3), and is used for: Drive the boom arm (4) to rotate at a preset angle. Based on the deflection deformation direction of the boom arm (4) collected by the photoelectric sensor (2), control the adjustable deflection mirror (3) to make a fine adjustment of the deflection angle in the opposite direction of the deflection deformation direction so that the laser rangefinder (1) receives the measurement beam emitted by itself. When the laser rangefinder (1) receives the measurement beam it emits, it reads the angle information of the current position of the adjustable deflection mirror (3) and the distance information measured by the laser rangefinder (1); and obtains the actual pose of the end of the boom arm (4).
2. The pose detection device for a multi-joint boom as described in claim 1, characterized in that: The end of the boom arm (4) is equipped with a pin or actuator for rotating the next boom arm (4).
3. The pose detection device for a multi-joint boom as described in claim 2, characterized in that: The boom arm (4) can be extended or fixed in length.
4. The pose detection device for a multi-joint boom as described in claim 1, characterized in that: The two radial sides perpendicular to the laser ranging direction are one side of the load action direction at the end of the boom arm (4) and the corresponding opposite side.
5. A posture control device for a multi-joint boom, characterized in that: The system includes a pose detection device for a multi-joint boom as described in any one of claims 1 to 4. The control system (5) is further configured to compare the actual pose of the end of the boom arm (4) with the theoretical pose, and adjust the rotation angle and length of the boom arm (4) according to the difference between the actual pose and the theoretical pose, so that the actual pose of the boom arm (4) coincides with the theoretical pose.
6. The pose control device for a multi-joint boom as described in claim 5, characterized in that: The theoretical pose includes the length of the boom arm (4) and the rotation angle of the boom arm (4) relative to the previous boom arm (4).
7. A control method for a pose control device for a multi-joint boom as described in any one of claims 5 to 6, characterized in that, Includes the following steps: Reset the adjustable angle reflector (3), turn on the laser rangefinder (1), and adjust the laser rangefinder (1) to receive the measurement beam emitted by itself. Read the angle information of the initial position of the adjustable angle reflector (3) and the initial distance information measured by the laser rangefinder (1) to obtain the initial pose of the end of the boom arm (4). The boom arm (4) is rotated at a preset angle and / or extended at a preset length based on the initial position. According to the deflection deformation direction of the boom arm (4) collected by the photoelectric sensor (2), the adjustable deflection mirror (3) is controlled to make a fine adjustment of the deflection angle in the opposite direction of the deflection deformation direction so that the laser rangefinder (1) can receive the measurement beam emitted by itself again. When the laser rangefinder (1) receives the measurement beam emitted by itself again, it reads the angle information of the current position of the adjustable deflection mirror (3) and the distance information measured by the laser rangefinder (1) to obtain the actual pose of the end of the boom arm (4); The actual pose of the end of the boom arm (4) is compared with the theoretical pose. Based on the difference between the actual pose and the theoretical pose, the rotation angle and length of the boom arm (4) are adjusted so that the actual pose of the boom arm (4) coincides with the theoretical pose.
8. The control method as described in claim 7, characterized in that, The steps of obtaining the actual pose of the end of the boom arm (4) and adjusting the rotation angle and length of the boom arm (4) according to the difference are repeated multiple times until the actual pose of the boom arm (4) coincides with the theoretical pose; wherein, before each iteration, the adjustable deflection mirror (3) is reset.