Inflatable structures, especially for robotic arms.
The inflatable structure with a guide member and return system addresses stability and reusability issues, achieving stable deployment and deflation with reduced weight and volume, enhancing space efficiency and cost-effectiveness.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- POLITECNICO DI TORINO
- Filing Date
- 2024-06-07
- Publication Date
- 2026-07-24
AI Technical Summary
Existing inflatable structures lack stability and controllability during deployment and deflation phases, are not reusable, and are heavy, leading to high transportation costs and inefficient use of space resources.
An inflatable structure with a guide member and return system, including a telescopic rod and electrically controlled valves, allows for controlled expansion and contraction, using a compact design with low inertia and lightweight materials like Kevlar and elastomers, enabling multiple cycles of deployment and retraction.
Ensures stable and repeatable deployment and deflation phases with reduced weight and volume, lowering transportation costs and providing equivalent functionality to rigid manipulator arms while reducing power consumption and overall system weight.
Smart Images
Figure 2026524785000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an inflatable type of structure as specified in the preamble of claim 1, and more particularly to an inflatable type of robotic arm for space applications (i.e., use in a low-gravity or zero-gravity environment), which can be used to create an inflatable type of structure that can replace a conventional rigid structure and has a low volume, low weight, and is more easily transportable. As an example, a robotic arm fabricated from an inflatable type of structure according to the present invention can be used for operations outside a spacecraft, such as maintenance, docking, or debris capture operations, or for operations inside a spacecraft, such as the work or experiments of astronauts.
[0002] However, it is also clear that the inflatable type of structure of the present invention can be used in any place where it is useful that it can be used for terrestrial applications, particularly for structures that can be easily transported (due to their low weight and low volume when contracted or packed), can be easily deployed and operated, and then repacked for transport again.
[0003] Currently in the art, several techniques are known that enable an inflatable type of structure to expand in outer space after being transported in a contracted or packed shape.
[0004] Inflatable types of structures known in the art can be folded using various techniques, which will result in various stabilities during inflation for each technique. Generally, a stage that would enable such a structure to return to its packed shape during inflation is not envisioned. For this reason, such structures, once deployed, are cured by various methods, for example, using thermosetting resins or curable foams. Thus, it is clear that after using such methods, the structure cannot be returned to its contracted or packed shape.
[0005] Applications using inflatable structures are typically designed to consist of dedicated, very slender booms supporting solar panels, satellite return modules, or inflatable antennas; in this regard, for example, inflatable environments capable of accommodating astronauts on a space station can also be created.
[0006] For example, recent tests have been conducted on the BEAM (Bigelow Expandable Activity Module) system, the International Space Station, and the LIFE (Large Integrated Flexible Environment) system.
[0007] In this framework, the main objective of the present invention is to provide an inflatable structure designed to overcome the shortcomings of prior art inflatable structures.
[0008] Therefore, one of the objectives of the present invention is to provide an inflatable structure that ensures control and stability in both the deployment or inflation phase and the deflating, packing, or contraction phase.
[0009] Another object of the present invention is to provide an inflatable structure that can guarantee that the deployment and deflating phases can be repeated multiple times with the same high quality.
[0010] Another object of the present invention is to provide an inflatable structure for creating a low-inertia robotic arm, particularly an inflatable type, which is designed to enable the use of small, lightweight motors and reduce the overall weight of the structure.
[0011] A further object of the present invention is to provide an inflatable structure for creating an inflatable robotic arm for space applications or use in outer space, which can significantly reduce the transportation costs incurred in transporting the structure to the intended location of use.
[0012] A further object of the present invention is to provide an inflatable structure for creating an inflatable robotic arm that is relatively lightweight and compact when transported in a deflated state, and when inflated, provides substantially the same functionality as a conventional rigid manipulator arm.
[0013] Another object of the present invention is to provide an inflatable structure that can provide a payload-to-weight ratio that enables significant cost savings, particularly for space applications. [Brief explanation of the drawing]
[0014] Further objects, features, and advantages of the present invention will become apparent in light of the following detailed description and accompanying drawings, which are provided herein merely as non-limiting illustrative examples.
[0015] [Figure 1] This is a perspective view of an inflatable structure according to the present invention. [Figure 2] This is a perspective view of the components of an inflatable structure according to the present invention. [Figure 3] This is a perspective view of an inflatable robotic arm, particularly for space applications, comprising at least one inflatable structure according to the present invention. [Modes for carrying out the invention]
[0016] Referring here to the attached drawings, in Figure 1, reference numeral 10 represents the entire inflatable structure according to the present invention; note that in Figure 1, structure 10 is shown in an inflated (or "deployed") state.
[0017] The structure 10 is, in particular, substantially cylindrical and comprises an external housing 10I that forms or encloses at least one liquid-tight chamber, the chamber being expanded with a fluid, such as a gas or liquid, by a generator or accumulator 10G.
[0018] In particular, the external housing 10I is made of a thin film material including a coating layer or additional layer made of a multilayer, high-strength, low-weight material such as Kevlar®, carbon fiber, or nylon, and an elastomer such as rubber to make the material liquid-tight. It should be noted that, in order to give the thin film material the ability to repair small punch holes, a self-healing material, such as that used in automatic leak-proof fuel tanks, may be used together with the fluid.
[0019] As far as the above-mentioned generator or accumulator 10G is concerned, in the embodiment shown in Figure 1, it consists of a tank or cylinder, in particular a high-pressure one (e.g., about 300 bar (about 30,000 kilopascals)), and is therefore very small; however, it is clear that the generator or accumulator 10G may be of a different type.
[0020] The structure 10 has a first end 10A with a first cap 11 and a second end 10B with a second cap 12. Preferably, the first cap 11 and the second cap 12 are made of a rigid material such as plastic, aluminum, carbon fiber, or the like; furthermore, they may be positioned inside the outer housing 10I, or each of them may be constructed to form a part of the outer housing 10I.
[0021] According to the present invention, the structure 10 comprises a guide member 13 constrained by the first cap 11 and the second cap 12, the guide member 13 being configured to extend and retract along the longitudinal axis A of the guide member 13 (shown as a dashed line in Figure 1), which substantially coincides with the longitudinal axis of the structure 10 (the longitudinal axis is not shown in Figure 1), so as to allow the second cap 12 and / or the first cap 11 to move along a direction substantially parallel to the longitudinal axis A during both the stage of deploying (or expanding) the structure 10 and the stage of retracting (or contracting) the structure 10.
[0022] In this regard, it should be noted that the guide member 13 is restrained by the first cap 11 and the second cap 12 either by fastening means (known in the art and not shown in the attached drawings) or by forming the end portions of the guide member 13 integrally with the first cap 11 and the second cap 12, respectively.
[0023] In a preferred embodiment, the guide member 13 includes an extendable rod, and the end conduit or end of the extendable rod is constrained by the first cap 11 and the second cap 12, respectively.
[0024] Preferably, the telescopic rod is constructed to include at least one anti-rotation element configured to prevent any mutual rotational movement of the first cap 11 and the second cap 12. In particular, the at least one anti-rotation element may include at least one element configured to prevent any rotational movement of the conduit constituting the telescopic rod; alternatively or additionally, the at least one anti-rotation element may include at least one element configured to prevent any rotational movement of the end conduit of the telescopic rod and the end conduits of the first cap 11 and the second cap 12 from which the end conduit is constrained.
[0025] According to the present invention, the above-described structure 10 also includes a return system 14, 15, 16 configured to return the second cap 12 toward the first cap 11 during the stage of retracting (or contracting) the above-described structure 10.
[0026] In one embodiment, the above return system is a reel 14 associated with the first cap 11; a cable 15, the ends of which are respectively constrained to the second cap 12 and the reel 14; and a driving element 16 associated with the reel 14 to rotate the reel 14 so as to wind at least a part of the cable 15 around the driving element 16 during the stage of retracting (or contracting) the above-described structure 10.
[0027] Preferably, the above cable 15 extends through a guide member 13 or a telescopic rod; further, the above driving element 16 may particularly include an electric type motor.
[0028] In this regard, it must be pointed out that during the stage of deploying (or expanding) the above-described structure 10, the above motor 16 is preferably configured not to receive a dragging torque.
[0029] According to the present invention, the above-described structure 10 may include at least one separator element 20 (also shown in FIG. 2) configured to divide the liquid-tight chamber formed by the external housing 10I into a plurality of sealed sub-chambers or sub-cells in order to ensure control of deployment (or expansion) and retraction (or contraction) even when its length far exceeds the diameter; for example, the above-described structure 10 may include a suitable number of separator elements 20 such that the length of each sub-chamber is equal to about 250 mm, and the above length is particularly measured in a direction substantially parallel to the deployment direction of the guide member 13.
[0030] As can be observed in Figure 2, the at least one separator element 20 is provided with at least one valve 21, 22 to enable the expansion (and thus deployment) and contraction (and thus retraction) of the liquid-tight chamber formed by the outer housing 10I of the structure 10, in particular to enable the expansion and contraction of each sub-chamber defined by the at least one separator element 20.
[0031] According to one embodiment, the at least one valve 21, 22 may be a two-way valve that allows the structure 10 to expand (from a remote pressure source consisting of the generator or accumulator 10G) and contract.
[0032] In a preferred embodiment (such as the embodiment shown in the attached drawings), at least one of the valves 21, 22 is: A first valve 21 connected to the generator or accumulator 10G for inflating the structure 10; The structure 10 is provided with a second valve 22 for contracting the structure 10, and in particular, the second valve 22 is connected to at least one channel 22A (shown by a dashed line in Figure 2 to indicate that the at least one channel 22A is preferably formed within the body of the separator element 20) for discharging fluid from the external housing 10I of the structure 10.
[0033] In all embodiments described above, the at least one valve 21, 22 is preferably an electrically controlled, normally closed on / off valve; in such a type of valve 21, 22, no power is consumed when the inflatable structure 10 is in operation, i.e., during all stages other than expansion and contraction. In this regard, it should be noted that the at least one valve 21, 22 is preferably connected to a control line of the structure 10, and the control line is configured to transmit control signals to the at least one valve 21, 22 and a generator or accumulator 10G in order to control the expansion and contraction of the structure 10.
[0034] Figure 2 also shows that at least one of the separator elements 20 preferably has a through hole 23 configured to allow a guide member 13 to pass through. In this regard, it should be noted that in one embodiment in which the guide member 13 is a telescopic rod and the structure 10 comprises a plurality of separator elements 20 (as shown as an example in Figure 1), the through hole 23 of each separator element 20 is sized to allow the corresponding conduit of the telescopic rod to pass through.
[0035] Preferably, at least one separator element 20 is substantially disc-shaped, and the through-hole 23 is substantially centered on the separator element 20; in this case, preferably, the separator element 20 is placed within a liquid-tight chamber formed by the outer housing 10I of the structure 10 such that the through-hole 13 unfolds along the longitudinal axis of the structure 10 (which then substantially coincides with the longitudinal axis A of the guide member 13).
[0036] Figure 3 shows an inflatable robotic arm (referred to as reference numeral 1) for space applications or use in outer space, comprising at least one structure 10 according to the present invention.
[0037] In this regard, the structure 10 is substantially cylindrical in shape, and its length is, for example, about 1 meter; however, it should be noted that the dimensions of the structure 10 may vary in particular depending on the specific task that the arm 1 must perform.
[0038] In particular, in the embodiment shown in Figure 3, the arm 1 comprises two structures 10, the first structure 10 being connected to the base 2 (which can then be connected to or fixed to the surface S) by a first articulated joint 3A, and the structures 10 being connected to each other by a second articulated joint 3B; however, it should be noted that according to the present invention, the arm 1 may comprise any number of structures 10 (or just one structure 10).
[0039] Next, the arm 1 may preferably include a tool 4 connected to the tip of an end structure 10 by a further articulated joint 3C. In this respect, defining the structure 10 to which the tool 4 is connected as the “end” means that such a structure 10 is the end structure of the arm 1; therefore, it can be said that the tool 4 is connected to the tip of the arm 1.
[0040] In the embodiment shown in Figure 3, the tool 4 consists of a grip unit or a clamp unit, in particular an electric unit; however, it is clear that the tool 4 may be of a different type.
[0041] Arm 1 also comprises at least one control line (not shown in the accompanying drawings), in particular an electrical control line, which connects Base 2 to the articulated joints 3A, 3B, 3C and / or tool 4, and the at least one control line is configured to transmit control signals from Base 2 to the articulated joints 3A, 3B, 3C and / or tool 4 in order to control the operation and movement of the at least one structure 10 and / or tool 4. The at least one control line may be located within the at least one structure 10 (i.e., within each structure 10 if Arm 1 comprises multiple structures 10); or the at least one control line may be provided on the outside or surface of the at least one structure 10 (i.e., on the outside or surface of each structure 10 if Arm 1 comprises multiple structures 10).
[0042] As far as the articulated joints 3A, 3B, and 3C are concerned, each structure 10 and / or tool 4 is constructed to move around at least one axis of rotation.
[0043] Preferably, the control line is of the electric type and is configured to electrically actuate the components of arm 1; an electric control system can be used that is less complex than the control systems used in pneumatically operated inflatable manipulators, and as a result, power management and motion control are easier compared to pneumatic operation, and in this respect, electric operation is advantageous over pneumatic operation.
[0044] The features and advantages of the inflatable structure 10 according to the present invention are clear from the above description.
[0045] In fact, the present invention makes it possible to overcome the shortcomings of prior art inflatable structures, particularly by providing an inflatable structure 10 used to create an inflatable robotic arm 1, the structure 10 being designed to include guide members 13 and return systems 14, 15, 16 that ensure the controllability and stability of the inflatable structure 10 during both the deployment or inflation phase and the retraction or packaging (or deflation) phase.
[0046] Therefore, it is clear that the provisions of the present invention make it possible to provide an inflatable type structure 10 used in particular to create an inflatable robot arm 1, thereby ensuring that the deployment and retraction stages can be repeated multiple times with the same high quality each time.
[0047] Furthermore, the pneumatic system employed to inflate the structure 10 according to the present invention is smaller and simpler than that of a prior art pneumatically operated inflatable manipulator.
[0048] Reducing the inertia of the robot arm 1 according to the present invention leads to a reduction in power consumption; in this respect, the electric operation of the robot arm 1 according to the present invention makes it possible to use a less complex control system than the control system used in the prior art pneumatically operated inflatable manipulator, and as a result, further advantages are obtained in terms of the total weight and total volume of the entire system including the robot arm 1 and the control system.
[0049] Furthermore, in this respect, the pneumatic system of the robot arm 1 according to the present invention does not require much energy to operate because energy is not used during the operation phase of the robot arm 1 (i.e., all states other than expansion and contraction), and is preferably supplied by a generator or accumulator 10G consisting of a very small high-pressure tank.
[0050] Therefore, it is clear that the provisions of the present invention make it possible to create a structure 10 (and a robot arm 1 comprising at least one structure 10 according to the present invention) that is both lightweight and compact when transported in a contracted state, and that provides the same functionality as a conventional rigid manipulator arm when expanded.
[0051] In addition, the structure 10 and robot arm 1 according to the present invention are designed to provide a payload-to-weight ratio that results in significant cost reductions.
[0052] As an example, the structure 10 and robot arm 1 described herein can be subject to many possible modifications without departing from the spirit of the novelty of the present invention, and it is also clear that in actual implementations of the present invention, the illustrative details may have different shapes or may be replaced with other technically equivalent elements.
[0053] Therefore, although the present invention is not limited to the structure 10 and robot arm 1 described above, it is readily apparent that many modifications, improvements, or substitutions of equivalent parts and elements are possible without departing from the spirit of the invention, as clearly defined in the following claims.
[0054] As an example, it is worth mentioning that the return system according to the present invention may be designed to include actuator means (not shown in the embodiments shown in the accompanying drawings) configured to act directly on the guide member 13 to cause the guide member 13 to contract or retract.
Claims
1. An inflatable structure (10), in particular substantially cylindrical, comprising an external housing (10I) that forms or encloses at least one liquid-tight chamber, wherein the chamber is inflated with fluid by a generator or accumulator (10G), Here, the structure (10) has a first end (10A) including a first cap (11), and a second end (10B) including a second cap (12), The aforementioned structure (10) is A guide member (13) constrained by the first cap (11) and the second cap (12), wherein the guide member (13) is configured to extend and retract along the longitudinal axis (A) of the guide member (13), substantially coinciding with the longitudinal axis of the structure (10), so as to allow the second cap (12) and / or the first cap (11) to move along a direction substantially parallel to the longitudinal axis (A) of the structure (10) during both the stage of deploying or inflating the structure (10) and the stage of retracting or contracting the structure (10); An inflatable structure (10) characterized by comprising a return system (14, 15, 16) configured to return the second cap (12) toward the first cap (11) during the step of retracting or shrinking the at least one structure (10).
2. The structure (10) according to claim 1, characterized in that the guide member (13) has an extendable rod, and the end conduit or end of the extendable rod is restrained by the first cap (11) and the second cap (12), respectively.
3. The structure (10) according to claim 2, characterized in that the telescopic rod is constructed to have at least one anti-rotation element configured to prevent any mutual rotational movement of the first cap (11) and the second cap (12).
4. The aforementioned return system The reel (14) associated with the first cap (11); A cable (15), the ends of which are constrained to the second cap (12) and the reel (14), respectively; The structure (10) according to one or more of claims 1 to 3, characterized in that, during the step of retracting or contracting the at least one structure (10), the structure (10) is further provided with an actuation element (16) associated with the reel (14) to rotate the reel (14) to wind at least a portion of the cable (15) onto the actuation element (16).
5. The structure (10) according to claim 4, characterized in that the cable (15) extends through the guide member (13).
6. The structure (10) according to one or more of claims 1 to 5, characterized by comprising at least one separator element (20) configured to divide the liquid-tight chamber formed by the external housing (10I) into a plurality of sealed sub-chambers or sub-cells.
7. The structure (10) according to claim 6, characterized in that the at least one separator element (20) has at least one valve (21, 22) that enables the expansion and contraction of the liquid-tight chamber formed by the outer housing (10I) of the structure (10), in particular, to expand and contract each sub-chamber defined by the at least one separator element (20).
8. The structure (10) according to claim 7, characterized in that at least one of the valves (21, 22) includes a two-way valve.
9. The at least one valve (21, 22) A first valve (21) connected to the generator or accumulator (10G) for inflating the structure (10); A second valve (22) for contracting the structure (10), in particular, the second valve (22) is connected to at least one channel (22A) for discharging the fluid from the outer housing (10I) of the structure (10). The structure (10) according to claim 7, characterized by having the following.
10. The structure (10) according to one or more of the prior claims 7 to 9, characterized in that at least one of the valves (21, 22) is electrically controlled and is a normally closed on / off valve.
11. The structure (10) according to one or more of claims 6 to 10, characterized in that at least one separator element (20) includes a through hole (23) configured to allow the guide member (13) to pass through.
12. The structure (10) according to one or more of claims 6 to 11, characterized in that at least one separator element (20) is substantially disc-shaped and the through hole (23) is located substantially in the center of the separator element (20).
13. The structure (10) according to claim 12, characterized in that the separator element (20) is arranged within the liquid-tight chamber formed by the outer housing (10I) of the structure (10) such that the through hole (13) is located along the longitudinal axis of the structure (10).
14. The structure (10) according to claim 13, characterized in that it comprises an electrical control line configured to electrically operate the components of the structure (10).
15. An inflatable robotic arm (1) for space applications, comprising at least one inflatable structure (10) according to one or more of claims 1 to 14.