CN111203912B - A five-degree-of-freedom flexible arm driven by a hybrid of fluid and tendon - Google Patents

Abstract

The five-freedom flexible arm driven by fluid and tendon rope mixture includes two-stage mechanism; the first-stage mechanism comprises a small end connecting flange, a large end connecting flange, a closed hollow tower type corrugated pipe-shaped flexible body and at least three bowden cable tendon ropes; the second-stage mechanism comprises a rigid platform and at least three steel wire rope tendons; a small end connecting flange and a large end connecting flange are respectively fixed on the small end and the large end of the closed hollow tower type corrugated pipe shaped flexible body, and at least three bowden cable tendon ropes are uniformly distributed on the outer side of the closed hollow tower type corrugated pipe shaped flexible body along the circumferential direction; the middle part of the rigid platform is connected with the middle part of the small end connecting flange, and the rigid platform swings relative to the small end connecting flange. The invention can realize the active rigidity changing capability, greatly enhances the load bearing capability of the flexible arm, and can quickly adjust the position and the posture of the tail end platform.

Description

Translated fromChinese

流体与腱绳混合驱动的五自由度柔性臂A five-degree-of-freedom flexible arm driven by fluid and tendon

技术领域technical field

本发明涉及一种柔性臂，具体涉及一种流体与腱绳混合驱动的五自由度柔性臂。The invention relates to a flexible arm, in particular to a five-degree-of-freedom flexible arm driven by fluid and tendon mixed.

背景技术Background technique

在机器人领域，随着机械臂技术不断发展成熟，柔性机械臂的研究目前已经成为了机器人研究领域内新的焦点。柔性机械臂是一种具有很多自由度的机器人系统，一般为欠驱动无穷自由度，本体结构通常由柔性材料制作，具有高柔顺性、复杂环境适应性及安全人机交互性等特点，研究涉及材料学、仿生、机械设计和制造、传感器技术等多学科交叉融合，其发展为柔性材料应用、仿生机器人研究等提供参考和技术支持，在工业生产、医疗手术、救灾探测、生活护理等方面具有广阔应用前景。现有柔性连续体机械臂中的驱动方式主要有线驱动，气动人工肌肉驱动以及低熔点合金驱动等。这些驱动方式中大多都对外部环境条件有较高要求，并且柔性臂本体刚度低，承载能力差，不具备承载重载荷作业能力。In the field of robotics, with the continuous development and maturity of robotic arm technology, the research on flexible robotic arms has now become a new focus in the field of robotics research. The flexible manipulator is a robot system with many degrees of freedom, generally underactuated with infinite degrees of freedom. The body structure is usually made of flexible materials, and has the characteristics of high flexibility, complex environment adaptability and safe human-computer interaction. The research involves Materials science, bionics, mechanical design and manufacturing, sensor technology and other multi-disciplinary cross-integration, its development provides reference and technical support for flexible material applications, bionic robot research, etc. Broad application prospects. The driving methods in the existing flexible continuum manipulators are mainly wired driving, pneumatic artificial muscle driving, and low-melting alloy driving. Most of these driving methods have high requirements on external environmental conditions, and the rigidity of the flexible arm body is low, the bearing capacity is poor, and it does not have the ability to carry heavy loads.

发明内容SUMMARY OF THE INVENTION

本发明为克服现有技术不足，提供一种流体与腱绳混合驱动的五自由度柔性臂。该柔性臂依靠流体压力与外部腱绳拉力形成耦合对抗，可实现主动变刚度的能力，大幅增强了柔性臂的载荷负重的能力，可实现快速调整末端平台的位置与姿态。In order to overcome the deficiencies of the prior art, the present invention provides a five-degree-of-freedom flexible arm driven by a fluid and a tendon. The flexible arm relies on the fluid pressure to form a coupling confrontation with the external tendon tension, which can realize the ability to actively change the stiffness, greatly enhance the load-bearing capacity of the flexible arm, and can quickly adjust the position and attitude of the end platform.

本发明的技术方案为：The technical scheme of the present invention is:

流体与腱绳混合驱动的五自由度柔性臂，它包括二级机构；第一级机构包括小端连接法兰、大端连接法兰、密闭中空塔式波纹管状柔性体和至少三根鲍登线腱绳；第二级机构包括刚性平台和至少三根钢丝绳腱绳；A five-degree-of-freedom flexible arm driven by a mixture of fluid and tendon, it includes a secondary mechanism; the first-level mechanism includes a small-end connecting flange, a large-end connecting flange, a closed hollow tower-type bellows-shaped flexible body and at least three Bowden wires tendons; the secondary mechanism includes a rigid platform and at least three wire rope tendons;

密闭中空塔式波纹管状柔性体的小端和大端分别上固定有小端连接法兰和大端连接法兰，密闭中空塔式波纹管状柔性体的大端面开有控制内部流体压力的驱动接口，至少三根鲍登线腱绳沿周向均布设置在密闭中空塔式波纹管状柔性体的外侧，并穿过密闭中空塔式波纹管状柔性体外侧上的侧耳通道，一端固定在小端连接法兰上，另一端穿过大端连接法兰由外部的驱动装置驱动；至少三根钢丝绳腱绳一一对应滑设于鲍登线腱绳内，一端伸出小端连接法兰并与刚性平台固接，另一端伸出鲍登线腱绳由外部驱动装置驱动，所述刚性平台中部与小端连接法兰中部连接，且刚性平台相对小端连接法兰作摆动。The small end and the large end of the closed hollow tower bellows-shaped flexible body are respectively fixed with a small end connecting flange and a large end connecting flange, and the large end face of the closed hollow tower bellows-shaped flexible body is provided with a drive interface for controlling the internal fluid pressure , at least three Bowden wire tendons are uniformly distributed on the outer side of the closed hollow tower bellows-shaped flexible body along the circumferential direction, and pass through the side ear channel on the outer side of the closed hollow tower bellows-shaped flexible body, and one end is fixed on the small end connecting flange , the other end is driven by the external driving device through the big end connecting flange; at least three steel wire rope tendons are slid in the Bowden wire rope one by one correspondingly, and one end extends out of the small end connecting flange and is fixed with the rigid platform, The other end protrudes from the Bowden wire and the tendon is driven by an external driving device. The middle part of the rigid platform is connected with the middle part of the small end connecting flange, and the rigid platform swings relative to the small end connecting flange.

进一步地，所述密闭中空塔式波纹管状柔性体的材质为聚氨酯热塑性弹性体。Further, the material of the closed hollow tower bellows-shaped flexible body is polyurethane thermoplastic elastomer.

本发明相比现有技术的有益效果是：Compared with the prior art, the present invention has the following beneficial effects:

1、本发明柔性臂在结构上采用了两级并联五自由度塔式结构设计，第一级机构为塔式的波纹管状结构，即可实现伸缩运动，也可实现各方向弯曲运动，变形幅度大，运动具有三自由度；第二级机构为绕轴心摆动的刚性平台结构，可进行二自由度摆动。1. The flexible arm of the present invention adopts a two-stage parallel five-degree-of-freedom tower structure design in structure, and the first-stage mechanism is a tower-type bellows structure, which can realize telescopic movement and bending movement in all directions. Large, the movement has three degrees of freedom; the second-level mechanism is a rigid platform structure swinging around the axis, which can swing with two degrees of freedom.

2、本发明柔性臂的驱动载体采用了流体与腱绳混合驱动，第一级结构塔式的波纹管状结构内部注入流体，流体压力与外部腱绳拉力形成耦合对抗，实现主动变刚度的能力，大幅增强了柔性臂的载荷负重的能力。2. The drive carrier of the flexible arm of the present invention adopts the mixed drive of fluid and tendon, and the bellows-shaped structure of the first-level structure tower is injected with fluid inside, and the fluid pressure forms a coupling confrontation with the external tendon tension, so as to realize the ability to actively change the stiffness, The load bearing capacity of the flexible arm is greatly enhanced.

3、柔性臂的第一级机构的塔式波纹管状柔性体采用3D打印方式制造的高强度聚氨酯弹性体橡胶(TPU)材料，邵氏硬度92A，该材料使第一级结构不仅实现了大幅度变形能力，又充分发挥出流体与腱绳作用力耦合，大幅提升了第一级结构的主动变刚度性能。3. The tower-type bellows-shaped flexible body of the first-level mechanism of the flexible arm is made of high-strength polyurethane elastomer rubber (TPU) material manufactured by 3D printing, with a Shore hardness of 92A. This material enables the first-level structure not only to achieve a large Deformation ability, and give full play to the force coupling between fluid and tendon, greatly improving the active variable stiffness performance of the first-level structure.

4、柔性臂的第二级机构采用轻质球轴承作为基座，三根腱绳施加作用力时，可使第二级结构实现快速摆动，调整刚性平台的位置与姿态。4. The second-level mechanism of the flexible arm uses a light-weight ball bearing as the base. When the three tendons exert force, the second-level structure can swing quickly and adjust the position and posture of the rigid platform.

下面结合附图和实施方式对本发明作进一步地说明：The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

附图说明Description of drawings

图1为本发明的流体与腱绳混合驱动的五自由度柔性臂的立体图；1 is a perspective view of a five-degree-of-freedom flexible arm driven by a fluid and a tendon hybrid according to the present invention;

图2为本发明的流体与腱绳混合驱动的五自由度柔性臂的主视图；Fig. 2 is the front view of the five-degree-of-freedom flexible arm driven by the hybrid of fluid and tendon of the present invention;

图3是沿图2的B-B线的剖视图；Fig. 3 is a cross-sectional view along line B-B of Fig. 2;

图4为图2的侧视图。FIG. 4 is a side view of FIG. 2 .

具体实施方式Detailed ways

下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然以下所描述的实施例是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the embodiments described below are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

参见图1-图4所示，本实施方式的流体与腱绳混合驱动的五自由度柔性臂，它包括二级结构；Referring to Figures 1-4, the five-degree-of-freedom flexible arm driven by the fluid and tendon in this embodiment includes a secondary structure;

第一级结构包括小端连接法兰1、大端连接法兰2、密闭中空塔式波纹管状柔性体3和至少三根鲍登线腱绳4；第二级结构包括刚性平台5和至少三根钢丝绳腱绳6；The first-level structure includes a small-end connecting flange 1, a large-end connecting flange 2, a closed hollow tower bellows-shapedflexible body 3 and at least three Bowdenwire tendons 4; the second-level structure includes arigid platform 5 and at least three steel wireropes tendon rope 6;

密闭中空塔式波纹管状柔性体3的小端和大端分别上固定有小端连接法兰1和大端连接法兰2，密闭中空塔式波纹管状柔性体3的大端面开有控制内部流体压力的驱动接口3-1，至少三根鲍登线腱绳4 沿周向均布设置在密闭中空塔式波纹管状柔性体3的外侧，并穿过密闭中空塔式波纹管状柔性体3外侧上的侧耳通道3-2，一端固定在小端连接法兰1上，另一端穿过大端连接法兰2由外部的驱动装置驱动；A small end connecting flange 1 and a largeend connecting flange 2 are respectively fixed on the small end and the large end of the closed hollow tower type bellows-shapedflexible body 3, and the large end face of the closed hollow tower type bellows-shapedflexible body 3 is opened with a control internal fluid. The drive interface 3-1 of the pressure, at least three Bowdenwire tendons 4 are uniformly arranged on the outer side of the closed hollow tower type bellows-shapedflexible body 3 along the circumferential direction, and pass through the side ear channel on the outer side of the closed hollow tower type bellows-shapedflexible body 3 3-2, one end is fixed on the small end connecting flange 1, and the other end is driven by the external driving device through the bigend connecting flange 2;

至少三根钢丝绳腱绳6一一对应滑设于鲍登线腱绳4内，一端伸出小端连接法兰1并与刚性平台5固接，另一端伸出鲍登线腱绳4由外部驱动装置驱动，所述刚性平台5中部与小端连接法兰1中部连接，且刚性平台5相对小端连接法兰1作摆动。At least three steelwire rope tendons 6 are slid in the Bowdenwire tendons 4 in one-to-one correspondence, one end extends out of the small end connecting flange 1 and is fixed with therigid platform 5, and the other end extends the Bowdenwire tendon 4 to be driven by the outside. When the device is driven, the middle part of therigid platform 5 is connected with the middle part of the small end connecting flange 1 , and therigid platform 5 swings relative to the small end connecting flange 1 .

本实施方式的五自由度柔性连续体机械臂由两级结构以并联方式连接构成，第一级机构为流体及腱绳混合驱动的三自由度塔式波纹管状柔性体结构；第二级机构为腱绳驱动的二自由度快速调整刚性平台结构。较优地，鲍登线腱绳4和钢丝绳腱绳6数量均为3根。三根就可实现密闭中空塔式波纹管状柔性体3的弯曲运动，与内部流体压力的改变产生耦合作用力，从而使柔性体产生任意方向的大幅度弯曲变形。三根鲍登线腱绳的通过以120°对称方式设置在密闭中空塔式波纹管状柔性体3外侧面上。如图1所示，通过驱动接口3-1可注入或抽取在结构内部的气体或液体等介质，随内部流体压力改变，密闭中空塔式波纹管状柔性体3也会产生伸长或缩短等变形。The five-degree-of-freedom flexible continuum manipulator in this embodiment is composed of two-level structures connected in parallel. The first-level mechanism is a three-degree-of-freedom tower-type bellows-shaped flexible body structure driven by a mixture of fluid and tendon; the second-level mechanism is Two degrees of freedom actuated by tendon cables to quickly adjust the rigid platform structure. Preferably, the number of Bowdenwire tendons 4 andwire rope tendons 6 is three. Only three pieces can realize the bending motion of the closed hollow tower bellows-shapedflexible body 3, and the change of the internal fluid pressure generates a coupling force, so that the flexible body can produce large bending deformation in any direction. The passages of the three Bowden wire tendons are arranged on the outer side of the closed hollow tower-type bellows-shapedflexible body 3 in a symmetrical manner of 120°. As shown in Figure 1, the medium such as gas or liquid inside the structure can be injected or extracted through the drive interface 3-1. With the change of the internal fluid pressure, the closed hollow tower-type bellows-shapedflexible body 3 will also be deformed by elongation or shortening. .

进一步地，所述密闭中空塔式波纹管状柔性体3的材质为聚氨酯热塑性弹性体。该材质耐磨性优异、耐臭氧性极好、硬度大、强度高、弹性好、耐低温，有良好的性能。所述密闭中空塔式波纹管状柔性体由3D打印制成。3D打印有利于快速成型。Further, the material of the closed hollow tower bellows-shapedflexible body 3 is polyurethane thermoplastic elastomer. The material has excellent wear resistance, excellent ozone resistance, high hardness, high strength, good elasticity, low temperature resistance and good performance. The closed hollow tower bellows-shaped flexible body is made of 3D printing. 3D printing facilitates rapid prototyping.

如图3所示，所述刚性平台5的中部通过球铰链7与小端连接法兰1的中部连接。通过驱动给三根钢丝绳腱绳施加对应的拉力，三根钢丝绳腱绳通过改变长度带动刚性平台5围绕球铰链7进行二自由度转动。As shown in FIG. 3 , the middle part of therigid platform 5 is connected with the middle part of the small end connecting flange 1 through the ball hinge 7 . By driving the three steel wire rope tendons to exert corresponding tensile force, the three steel wire rope tendons drive therigid platform 5 to rotate around the ball hinge 7 with two degrees of freedom by changing the length.

通常，所述密闭中空塔式波纹管状柔性体3的内外面上分别覆盖有密封剂层。中空塔式波纹管状柔性体气密性处理方法是这样的：消泡处理：将密封剂倒入烧杯，将烧杯放置于真空桶中，并对真空桶抽真空，去除密封剂中的气泡；灌涂处理：将中空塔式波纹管状柔性体(聚氨酯热塑性弹性体)完全浸入经消泡处理后的含有密封剂的烧杯中，静置10秒，将静置后的柔性体从烧杯中取出，使多余的密封剂从驱动接口自然流出，保证柔性体内外两面均被密封剂覆盖；干燥处理：将经灌涂处理的柔性体置于真空桶中静置12小时，使密封剂自然干燥，得到密封性良好的塔式波纹管状柔性体。优选地，密封剂采用TPU密封剂，它是以合成特殊分子结构的聚氨酯树脂为主，含酯，酮，苯类溶剂的试剂。应用于微孔密封，解决气密性问题。优选地，如图1-图3所示，密闭中空塔式波纹管状柔性体3的截面呈圆锥形。圆锥形结构为周向为圆环形，无死角，内部压力控制均匀稳定。Usually, the inner and outer surfaces of the closed hollow tower bellows-shapedflexible body 3 are respectively covered with a sealant layer. The air-tightness treatment method of the hollow tower bellows-shaped flexible body is as follows: defoaming treatment: pour the sealant into a beaker, place the beaker in a vacuum barrel, and vacuum the vacuum barrel to remove the air bubbles in the sealant; Coating treatment: Fully immerse the hollow tower bellows-shaped flexible body (polyurethane thermoplastic elastomer) into the defoamed beaker containing the sealant, let it stand for 10 seconds, and take out the static flexible body from the beaker to make the coating process. The excess sealant flows out naturally from the drive interface to ensure that both sides of the flexible body are covered by the sealant; drying treatment: put the filled flexible body in a vacuum bucket for 12 hours to allow the sealant to dry naturally and seal A tower-type bellows-shaped flexible body with good performance. Preferably, the sealant is a TPU sealant, which is mainly composed of polyurethane resin with special molecular structure and contains ester, ketone, and benzene solvents. Used in micropore sealing to solve air tightness problems. Preferably, as shown in FIG. 1 to FIG. 3 , the section of the closed hollow tower bellows-shapedflexible body 3 is conical. The conical structure is circular in the circumferential direction, without dead angle, and the internal pressure control is uniform and stable.

本发明已以较佳实施案例揭示如上，然而并非用以限定本发明，任何熟悉本专业的技术人员，在不脱离本发明技术方案范围内，当可以利用上述揭示的结构及技术内容做出些许的更动或修饰为等同变化的等效实施案例。The present invention has been disclosed above with preferred embodiments, but it is not intended to limit the present invention. Any person skilled in the art, without departing from the scope of the technical solution of the present invention, can make use of the structure and technical content disclosed above to make some Changes or modifications are equivalent implementations of equivalent changes.

Claims (6)

1. The five-freedom-degree flexible arm driven by fluid and tendon rope is characterized in that: it comprises a two-stage mechanism;

the first-stage mechanism comprises a small end connecting flange (1), a large end connecting flange (2), a closed hollow tower type corrugated pipe-shaped flexible body (3) and at least three Bowden wire tendon ropes (4);

the second-stage mechanism comprises a rigid platform (5) and at least three steel wire rope tendons (6);

a small end connecting flange (1) and a large end connecting flange (2) are respectively fixed on the small end and the large end of the closed hollow tower type corrugated pipe shaped flexible body (3), a driving interface (3-1) for controlling the internal fluid pressure is arranged on the large end surface of the closed hollow tower type corrugated pipe shaped flexible body (3), at least three bowden cable tendon ropes (4) are uniformly distributed on the outer side of the closed hollow tower type corrugated pipe shaped flexible body (3) along the circumferential direction and penetrate through a side ear channel (3-2) on the outer side of the closed hollow tower type corrugated pipe shaped flexible body (3), one end of each bowden cable tendon rope is fixed on the small end connecting flange (1), and the other end of each bowden cable rope penetrates through the large end connecting flange (2) and is driven by an external driving device;

at least three steel wire rope tendon ropes (6) are arranged in the Bowden wire tendon rope (4) in a sliding mode in a one-to-one correspondence mode, one end of each steel wire rope tendon rope stretches out of the small end connecting flange (1) and is fixedly connected with the rigid platform (5), the other end of each steel wire rope tendon rope stretches out of the Bowden wire tendon rope (4) and is driven by an external driving device, the middle of the rigid platform (5) is connected with the middle of the small end connecting flange (1), and the rigid platform (5) swings relative to the small end connecting flange (1).

2. The fluid and tendon rope hybrid driven five degree of freedom flexible arm of claim 1, wherein: the closed hollow tower type corrugated pipe shaped flexible body (3) is made of a polyurethane thermoplastic elastomer.

3. The fluid and tendon rope hybrid driven five degree of freedom flexible arm according to claim 1 or 2, wherein: the closed hollow tower type corrugated pipe shaped flexible body (3) is manufactured by 3D printing.

4. The fluid and tendon rope hybrid driven five degree of freedom flexible arm of claim 3, wherein: the middle part of the rigid platform (5) is connected with the middle part of the small end connecting flange (1) through a ball hinge (7).

5. The fluid and tendon rope hybrid driven five degree of freedom flexible arm of claim 4, wherein: sealant layers are respectively covered on the inner surface and the outer surface of the closed hollow tower type corrugated pipe shaped flexible body (3).

6. The fluid and tendon rope hybrid driven five degree of freedom flexible arm of claim 5, wherein: the section of the closed hollow tower type corrugated pipe shaped flexible body (3) is conical.

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