System for remote actuation of articulated mechanisms

Abstract

A system (10) for remote actuation of an articulated mechanism, comprising at least one actuated group (200), the actuated group (200) comprising a mechanical joint (210) having at least one degree of freedom and at least one receiving hydraulic cylinder (250, 250', 250'') connected to the mechanical joint (210). The system (10) also comprises, for each actuated group (200), a hydrostatic transmission comprising a first hydraulic line (151) and a second hydraulic line (152) arranged to actuate each receiving hydraulic cylinder (250, 250', 250'') to generate a mechanical action on the mechanical joint (210) proportional to a pressure difference ΔP=P1-P2, where P1 is the fluid pressure in the first hydraulic line (151) and P2 is the fluid pressure in the second hydraulic line (152). In this case, the system (10) comprises an actuation unit (11) comprising at least one actuating group (100) configured to be connected to a respective actuated group (200) by a first hydraulic line (151) and a second hydraulic line (152), each actuating group (100) comprising at least one transmission hydraulic cylinder (150, 150', 150'') arranged to vary a pressure difference AP existing between the first hydraulic line (151) and the second hydraulic line (152). In particular, each actuating group (100) also comprises a pressure difference ΔP=ΔP L a first actuator (110) arranged to actuate each transmission hydraulic cylinder (150, 150', 150'') to generate a pressure differential ΔP=ΔP H >5*ΔP L and a second actuator (120) arranged to actuate each transmission hydraulic cylinder (150, 150', 150'') to generate

Description

[Technical field]

[0001] The present invention relates to the field of remote actuation of articulated mechanisms.

[0002] In particular, the present invention relates to a system for remote actuation of an industrial robot or other machine utility through the use of a hydrostatic transmission. [Background technology]

[0003] Hydrostatic transmissions have recently offered the promise of combining the characteristics of speed and repeatability typical of industrial robots with the characteristics of high interactivity and safety typical of collaborative robots.

[0004] Unlike alternative solutions for remote actuation of robot joints, hydrostatic transmissions offer particular simplicity of integration into the robot structure, with the additional properties of modularity, reduced cost, simplicity of measurement, construction and assembly.

[0005] Some examples of systems for robot actuation by hydrostatic transmission are shown, for example, in Whitney et al., A hybrid hydrostatic transmission and human-safe haptic telepresence robot, 2016, DOI: 10.1109 / ICRA.2016.7487195 and Veronneau et al., A Lightweight Force-Controllable Wearable Arm Based on Magnetorheological-Hydrostatic Actuators, 2019, DOI: 10.1109 / ICRA.2019.8793978.

[0006] A further example is given in M. Bolignari and M. Fontana, Design and experimental characterization of a high performance hydrostatic transmission for robot actuation, 2020, DOI: 10.1007 / s11012-020-01143-z. This document describes a system for transmitting hydrostatic torque between a remotely located actuation unit and one or more robots to be moved. In particular, the solution is based on a particular floating cylinder architecture (rolling diaphragm hydrostatic transmission) that makes it possible to reduce friction in the transmission, generate high torques and ensure low overall dimensions and manufacturing costs.

[0007] However, in all the cited documents no compromise is found between the speed of execution of the movements, essential to accelerate industrial processes, and the controllability of the generated torque, essential to give the movements a high degree of dexterity and to provide a safe interaction with the operator.

[0008] As is known, in fact, the actuators usually used to actuate robotic systems are characterized by a high mechanical impedance (gear motors, hydraulic cylinders, etc.) so as to generate a torque / force sufficient to support the weight of the robot and any object connected to it. However, due to their high inertia, these actuators are not safe for interaction with a human operator and usually have a low actuation band.

[0009] On the other hand, the use of actuators with low mechanical impedance (direct drive electric motors, moving coil motors, etc.) are safer for human interaction and allow the creation of mechanical systems with wide actuation bands, but generally provide torque / forces that are too low to support the weight of a robot or manipulate objects.

[0010] There is therefore a need to provide an actuation system which makes it possible to simultaneously obtain high performance and a high level of safety in the interaction.

[0011] Moreover, to date, despite the high flexibility offered by hydrostatic technology and the concept of numerous implementation and / or application variations, each single robot joint is remotely connected to an associated electric motor by a single hydrostatic transmission, this structure remains unchanged in the current state of the art, and the presence of a certain number of robot joints always implies the use of at least an equal number of electric motors. Summary of the Invention

[0012] It is therefore a feature of the present invention to provide a system for remote actuation of articulated mechanisms that makes it possible to ensure the generation of high torques at low frequencies and moderate torques at high frequencies, while at the same time making it possible to move substantial loads with good execution speeds and high precision of position and force.

[0013] It is also a feature of the present invention to provide such a system which ensures a high degree of security of interaction with a human operator.

[0014] It is also a feature of the present invention to provide a system that allows for the use of a single actuator to alternately actuate multiple mechanical joints.

[0015] These and other objects are directed to a system for remote actuation of an articulated mechanism, the system comprising: at least one actuated group, a mechanical joint having at least one degree of freedom; - at least one actuated group comprising at least one receiving hydraulic cylinder connected to a mechanical joint; - a hydrostatic transmission comprising, for each actuated group, a first hydraulic line and a second hydraulic line arranged to actuate the or each receiving hydraulic cylinder to generate a mechanical action at a mechanical joint proportional to a pressure difference ΔP=P1-P2, where P1 is the fluid pressure in the first hydraulic line and P2 is the fluid pressure in the second hydraulic line; an actuation unit comprising at least one actuating group configured to be connected to a respective actuated group by a first hydraulic line and a second hydraulic line, or each actuating group comprising at least one transmission hydraulic cylinder adapted to vary a pressure difference ΔP existing between the first hydraulic line and the second hydraulic line, The above or each operating group has a pressure difference ΔP = ΔP L or a first actuator arranged to actuate each transmission hydraulic cylinder to generate The main feature is that the above or each operating group has a pressure difference ΔP = ΔP H >5*ΔP L This is achieved by a system for remote actuation of the articulation mechanism which also includes a second actuator arranged to actuate each transmission hydraulic cylinder to generate a second actuator.

[0016] Advantageously, the second actuator is a pneumatic actuator.

[0017] Alternatively, the second actuator is a hydraulic actuator.

[0018] In particular, the second actuator is an electric actuator having a reducer with a reduction ratio of more than ten.

[0019] Advantageously, the second actuator is connected in series with an elastic element. Thanks to the elastic element, the actuation group of the invention allows the torques generated by the first and second actuators to be decoupled in frequency. In particular, the first actuator allows the generation of low torques up to high frequencies, providing high actuation speeds for the mechanical joints, while the second actuator allows the generation of high torques at low frequencies, increasing the load capacity of the system without increasing its inertia.

[0020] In particular, the first actuator is an electric actuator having a reducer with a reduction ratio of less than ten.

[0021] Advantageously, the first actuator is a voice coil actuator.

[0022] Specifically, the first actuator comprises two coils stacked on top of each other to share the same magnetic field.

[0023] Alternatively, the second actuator may be H the transmission hydraulic cylinder.

[0024] Advantageously, the or each actuated group comprises: - a first receiving hydraulic cylinder arranged to actuate the mechanical joint in a first direction; a second receiving hydraulic cylinder arranged to actuate the mechanical joint in a second direction.

[0025] In particular, the or each working group comprises a first transmission hydraulic cylinder and a second transmission hydraulic cylinder.

[0026] Advantageously, the first transmission hydraulic cylinders are adapted to be connected to respective first receiving hydraulic cylinders by respective first hydraulic lines, and the second transmission hydraulic cylinders are adapted to be connected to respective second receiving hydraulic cylinders by respective second hydraulic lines.

[0027] Specifically, the first receiving hydraulic cylinder and the second receiving hydraulic cylinder are connected by a belt to a pulley that is arranged to rotate with alternating movement of the receiving hydraulic cylinders.

[0028] Specifically, the first transmission hydraulic cylinder and the second transmission hydraulic cylinder are connected by a belt to pulleys arranged to be rotated by the first actuator and the second actuator to generate relative positional variation between the transmission hydraulic cylinders.

[0029] Advantageously, the actuation unit comprises at least two actuation groups and the system is arranged to actuate at least two mechanical joints.

[0030] Specifically, at least two voice coil actuators are stacked on top of each other to share the same magnetic field.

[0031] In particular, a changeover system is also provided which is arranged to enable the actuation groups to be alternately connected to the hydraulic lines of at least two mechanical joints. [Brief description of the drawings]

[0032] The invention is illustrated by means of the following description of illustrative but non-limiting embodiments with reference to the accompanying drawings, in which: [Figure 1A] 1 shows a schematic representation of a first embodiment of a system for remote actuation of an articulation mechanism according to the invention, in which a single transmission hydraulic cylinder and a single receiving hydraulic cylinder are provided; [Figure 1B] 2 shows diagrammatically a second embodiment of a system for remote actuation of an articulation mechanism according to the invention, in which two transmission hydraulic cylinders and two receiving hydraulic cylinders are provided; [Figure 2A] 1 shows a possible embodiment of the system's working group, where a single rotating transmission hydraulic cylinder is provided. [Figure 2B] 1 shows a possible embodiment of an actuation group of the system where a single transmission hydraulic cylinder is provided and the first actuator is a voice coil actuator. [Figure 3A] Two possible embodiments of the system's working group are shown, in which two transmission hydraulic cylinders are provided. [Figure 3B] Two possible embodiments of the system's working group are shown, in which two transmission hydraulic cylinders are provided. [Figure 4] 1 shows a possible embodiment of an actuating group of the system, where the first actuator is a voice coil actuator with two stacked coils. [Figure 4A] 5 illustrates a schematic diagram of the operation of the voice coil actuator of FIG. [Diagram 5] 1 shows a possible embodiment of an actuation unit of the system, comprising three actuation groups stacked voice coil actuators. [Figure 6] 1 shows a possible mechanical solution for the actuated group. [Figure 6A] 7 shows a cross-sectional view of the actuated group of FIG. 6. [Figure 7] 1 shows a possible mechanical solution for the cylinders of the working group. [Figure 8] 1 illustrates generally one embodiment of a system for remote actuation of an articulation mechanism, where a switching system is also provided. Description of the Preferred Embodiments

[0033] FIG. 1A shows diagrammatically a first embodiment of a system 10 for remote actuation of an articulation mechanism according to the present invention, providing an actuation group 100 which, in use, is connected to an actuated group 200.

[0034] Specifically, actuating group 100 includes a first actuator 110 and a second actuator 120, both connected to a single transmission hydraulic cylinder 150. The chambers of transmission hydraulic cylinder 150 are connected by respective hydraulic lines 151 and 152 to respective receiving hydraulic cylinders 250 disposed in actuated group 200.

[0035] The actuators 110 and 120 are configured to actuate the cylinder 150 to generate a pressure difference ΔP between the first hydraulic line 151 and the second hydraulic line 152. Such pressure difference ΔP allows the operation of the receiving hydraulic cylinder 250 which in turn generates a mechanical effect on the mechanical joint 210 that is proportional to the pressure difference ΔP itself. Such a mechanical effect can in particular be a force or a torque.

[0036] Specifically, the first actuator 110 has a torque of ΔP=ΔP L while the second actuator 120 is adapted to generate a pressure difference between the hydraulic lines equal to the pressure difference ΔP=ΔP H >5*ΔP L In this manner, the pressure difference ΔP generated by the second actuator 120 H The mechanical action that the receiving hydraulic cylinder 250 generates on the mechanical joint 210 due to the effect of the pressure difference ΔP generated by the first actuator 110 L The mechanical action is at least five times greater than that generated due to

[0037] Furthermore, the present invention provides that the second actuator 120 comprises or is connected to a mechanical compliance. This mechanical compliance can be introduced, for example, by using a pneumatic actuator as the second actuator 120. Alternatively, as shown in FIG. 1A, the second actuator 120 can be placed in series with an elastic element 125.

[0038] Thanks to the mechanical compliance of the actuator 120 or the elastic element 125, the actuation group 100 of the present invention allows for a decoupling in frequency of the torques generated by the first actuator 110 and the second actuator 120. In particular, the first actuator 110 allows for the generation of a non-high torque at a high frequency, providing a high actuation speed to the mechanical joint 210, while the second actuator 120 allows for the generation of a high torque at a low frequency, increasing the load capacity of the system without increasing its inertia.

[0039] 1B shows an alternative embodiment of the invention, in which the actuated group 200 comprises a first receiving hydraulic cylinder 250' suitable for moving the mechanical joint 210 in a first direction and a second receiving hydraulic cylinder 250'' suitable for moving the mechanical joint 210 in a second direction. Furthermore, the actuating group 100 comprises a first transmission hydraulic cylinder 150' and a second transmission hydraulic cylinder 150'' which can be connected to the respective receiving hydraulic cylinders 250', 250'' by respective hydraulic lines 151, 152.

[0040] The use of a pair of hydraulic cylinders instead of a single cylinder makes it possible to use flexible mechanical transmissions (e.g. belts, chains, cables, etc.) to convert the linear motion of the cylinders into the rotational motion of the joints. This solution makes it possible to obtain geometrically advantageous dimensions adapted to robotic applications.

[0041] According to the present invention, the system 10 can also provide for the presence of a transmission hydraulic cylinder 150 connected to two separate receiving hydraulic cylinders 250′, 250″, and conversely, for the presence of two transmission hydraulic cylinders 150′, 150″ connected to two chambers of the same receiving hydraulic cylinder 250.

[0042] 2A and 2B show a possible embodiment of the working group 100 in which there is a single transmission hydraulic cylinder 150, similar to that shown in the diagram of FIG. 1A.

[0043] Specifically, in the solution of Fig. 2A, both the first actuator 110 and the second actuator 120 are rotary actuators capable of generating a torque that is transferred to the axis of a rotating hydraulic cylinder 150. Specifically, the actuators 110 and 120 rotate the bulkhead of the toroidal shaped hydraulic cylinder 150 so as to generate a desired pressure difference ΔP between hydraulic lines 151 and 152 suitable for connection to the outlets 151' and 152'. Furthermore, in this embodiment, the second actuator 120 is placed in series with a torsion type elastic element 125 so as to isolate the inertia of the actuator 120 in the dynamic regime and to protect this actuator from any dynamic overload.

[0044] In this embodiment, both actuators 110 and 120 can be electric actuators connected to suitable reducers. For example, the first actuator 110 can be connected to a reducer with a reduction ratio of less than 10, and the second actuator 120 can be connected to a reducer with a reduction ratio of more than 10. Thus, the first actuator 110 generates a medium torque at high speeds and the second actuator 120 generates a high torque at low speeds.

[0045] Alternatively, the second actuator 120 may be a passive, non-electrically driven actuator. For example, the second actuator 120 may generate a torque due to the elastic potential energy of a spring or due to the gravitational potential energy of a counterweight. This solution may be particularly suitable for example to counteract and compensate for the effects of gravity acting on a robot link connected to the mechanical joint 210.

[0046] 2B instead shows an embodiment of the invention in which the first actuator 110 and the second actuator 120 are linear actuators and the elastic element 125 is also of the linear type. Specifically, in this solution, the first actuator 110 is a voice coil actuator comprising a coil 115 and four permanent magnets 116. In this embodiment, the linear motion generated by the actuator 110 acts by translating the bulkhead of the hydraulic cylinder 150 and thus by varying the pressure difference ΔP between hydraulic lines 151 and 152 adapted to be connected to the outlets 151′ and 152′.

[0047] 3A and 3B show two embodiments of the invention in which, similar to the diagram in FIG. 1B, there are two transmission hydraulic cylinders 150′ and 150″ connected to a transmission that converts the rotary motion of the actuators 110 and 120 into linear motion.

[0048] Specifically, in the solution of FIG. 3A, thanks to this transmission system, the movable partitions of the hydraulic cylinders 150′ and 150″ translate in opposite directions relative to each other, increasing the pressure in the internal chamber of the first cylinder and decreasing the pressure in the internal chamber of the other cylinder, so as to preferably vary the pressure difference ΔP between the hydraulic lines 151 and 152 suitable for connection to the outlets 151′ and 152′.

[0049] On the other hand, in the solution of FIG. 3B, the internal bulkhead remains fixed, but the external cylindrical bodies of hydraulic cylinders 150' and 150'' translate in opposite directions relative to each other, producing the same effect as the solution of FIG. 3A.

[0050] FIG. 4 shows a variant embodiment of the solution shown in FIG. 2B, in which two transmission hydraulic cylinders 150′, 150″ are provided, and the first actuator 110 comprises two coils 115 stacked one above the other, separated by a permanent magnet 116, and is able to transmit motion to both hydraulic cylinders 150′, 150″.

[0051] As shown in Fig. 4A, in this embodiment, the two coils 115, thanks to their overlapping position, utilize the same magnetic field, schematized in the figure by the circular arrows. As indicated by the horizontal grey arrows, the two coils 115 move in opposite directions to each other so as to preferably vary the pressure difference ΔP between the hydraulic lines 151 and 152 suitable for connection to the outlets 151' and 152', in a manner completely similar to that described for the embodiment of Figs. 3A and 3B.

[0052] FIG. 5 shows an embodiment of the invention in which the actuation unit 11 comprises three actuation groups 100 of the type shown in FIG. 4, the first actuators 110 being voice coil actuators stacked on top of each other to utilize the same magnetic field, reducing the overall weight and size of the actuation unit 11.

[0053] 6 and 6A show a possible mechanical embodiment of the actuated group 200, in which the receiving hydraulic cylinders 250', 250'' are floating cylinders connected by a belt 260 to a pulley 270 which can rotate as a result of variations in the relative position between the cylinders themselves.

[0054] Specifically, fluid coming from hydraulic lines 151 and 152 is conveyed through outlets 151' and 152' and manifold 280 towards respective chambers 253' and 253'', which are watertight sealed by rolling diaphragms 255' and 255'', which can slide to translate cylinders 250' and 250'', respectively. In this way, a pressure difference ΔP existing between hydraulic lines 151 and 152 is transmitted to rolling diaphragms 255' and 255'', which generates an opposite translation of receiving hydraulic cylinders 250' and 250'', respectively. This translation generates a transmission of torque by belt 260 to pulley 280, which in turn drives mechanical joint 210 (not shown).

[0055] In this embodiment, the manifold 280 acts as a structural element of the actuated joint 200, supporting the axis of rotation of the pulley 270 and the stationary elements of the two hydraulic cylinders 250' and 250'', in addition to allowing fluid to be conveyed into the chambers 253' and 253'',. Furthermore, the manifold 280 allows for the accommodation of two pressure sensors 290' and 290'', close to the hydraulic cylinders 250' and 250'', thereby allowing possible position and / or force control in a closed loop.

[0056] In particular, the hydraulic cylinders 250' and 250'' are equipped with suitable bleed valves 254' and 254'' to allow replacement of fluid in the two hydraulic lines 151 and 152 and the evacuation of gas and air.

[0057] This construction solution is very compact and functional, making it ideally suited to be installed in articulated mechanisms, in particular in industrial robots.

[0058] With reference to FIG. 7, the invention provides that this mechanical solution can also be used in a completely analogous way for the actuating joint 100, replacing the receiving hydraulic cylinders 250′ and 250″ with the transmission hydraulic cylinders 150′ and 150″. In this case, the pulley 170, actuated by the actuators 110 and 120, translates the floating cylinders 150′ and 150′ in opposite directions thanks to the belt 160, so as to generate the desired pressure difference ΔP between the hydraulic lines 151 and 152. In this case, thanks to the rolling diaphragms present both in the transmission hydraulic cylinders 150′ and 150″ and in the receiving hydraulic cylinders 250′ and 250″, the fluid present in each hydraulic line 151, 152 appears to move in a closed system defined by the respective chambers of the hydraulic cylinders present in the actuating joint 100 and the actuated joint 200.

[0059] 8 shows a possible embodiment of a system 10 for remote actuation of an articulation mechanism according to the invention, the system 10 also including a switching system 16 allowing each actuation group 100 to be alternately connected to a different actuated group 200 and thus to various articulation mechanisms. In this way, it is possible to use a smaller number of actuation groups 100 for the articulation mechanism to be actuated, reducing the cost and overall size of the system 10.

[0060] In particular, the switching system 16 may include hydraulic valves that can connect and disconnect an actuated group 200 to a particular actuating group 100, or even reverse the connection of two actuated groups 200 to their respective actuating groups 100, when the actuating groups 100 are different from one another and it is desirable to vary the type of actuation of the articulation mechanism.

[0061] Alternatively, the switching system 16 may simply comprise a mechanism for quick coupling and disengagement of the hydraulic lines 151 and 152, thereby allowing manual or mechanical connection and disconnection of the actuated group 200 from the respective actuating group 100.

[0062] It is to be understood that the above described embodiments of the present invention will fully clarify the present invention according to a conceptual point of view, so that others can modify and / or adapt such embodiments for various applications by applying current knowledge without further study and without departing from the present invention, and therefore such adaptations and modifications must be considered as equivalent to the specific embodiments. The means and materials for achieving different functions described herein can be of different natures for this reason without departing from the field of the present invention. It is to be understood that the expressions or terms employed in this specification are for the purpose of description and not limitation.

Claims

1. A system (10) for remote actuation of an articulated mechanism, said system (10) comprising: at least one actuated group (200), a mechanical joint (210) with at least one degree of freedom; at least one actuated group (200) comprising at least one receiving hydraulic cylinder (250, 250', 250'') connected to said mechanical joint (210); For each actuated group (200), the pressure difference ΔP=P １ -P ２ 1. A hydrostatic transmission comprising a first hydraulic line (151) and a second hydraulic line (152) arranged to actuate the or each receiving hydraulic cylinder (250, 250', 250'') to generate a mechanical action on said mechanical joint (210) proportional to P １ is the fluid pressure in the first hydraulic line (151), and P ２ is the fluid pressure in the second hydraulic line (152); an actuation unit (11) comprising at least one actuation group (100) configured to be connected to a respective actuated group (200) by said first hydraulic line (151) and said second hydraulic line (152), said or each actuation group (100) comprising at least one transmission hydraulic cylinder (150, 150', 150'') arranged to vary said pressure difference ΔP existing between said first hydraulic line (151) and said second hydraulic line (152); The or each working group (100) has a pressure difference ΔP=ΔP Ｌ a first actuator (110) arranged to actuate the or each transmission hydraulic cylinder (150, 150', 150'') to generate The system (100) is configured such that the or each working group (100) has a pressure differential ΔP=ΔP Ｈ >5*ΔP Ｌ a second actuator (120) arranged to actuate the or each transmission hydraulic cylinder (150, 150', 150'') to generate

2. The system (10) for remote actuation of an articulation mechanism according to claim 1, wherein the second actuator (120) is an electric actuator having a reducer with a reduction ratio of more than 10.

3. 2. The system (10) for remote actuation of an articulation mechanism according to claim 1, wherein the second actuator (120) is connected in series with an elastic element (125).

4. The system (10) for remote actuation of an articulation mechanism according to any one of claims 1 to 3, wherein the first actuator (110) is an electric actuator having a reducer with a reduction ratio of less than 10.

5. The system (10) for remote actuation of an articulation mechanism according to claim 1, wherein the first actuator (110) is a voice coil actuator.

6. 6. The system (10) for remote actuation of an articulation mechanism according to claim 5, wherein the first actuator (110) comprises two coils (115) stacked on top of each other to share the same magnetic field.

7. The second actuator (120) controls the pressure difference ΔP Ｈ 2. The system (10) for remote actuation of an articulation mechanism according to claim 1, wherein the system is arranged to convert elastic and / or gravitational potential energy into mechanical action on the or each transmission hydraulic cylinder (150, 150', 150'') to generate

8. The or each actuated group (200) a first receiving hydraulic cylinder (250') arranged to actuate said mechanical joint (210) in a first direction; - a second receiving hydraulic cylinder (250'') arranged to actuate the mechanical joint (210) in a second direction.

9. 2. A system (10) for remote actuation of an articulation mechanism according to claim 1, wherein the or each actuation group (100) comprises a first transmission hydraulic cylinder (150') and a second transmission hydraulic cylinder (150'').

10. 10. The system (10) for remote actuation of an articulation mechanism according to claim 8 or 9, wherein the first transmission hydraulic cylinders (150′) are adapted to be connected to respective first receiving hydraulic cylinders (250′) by respective first hydraulic lines (151), and the second transmission hydraulic cylinders (150″) are adapted to be connected to respective second receiving hydraulic cylinders (250″) by respective second hydraulic lines (152).

11. 9. The system (10) for remote actuation of an articulation mechanism according to claim 8, wherein the first receiving hydraulic cylinder (250′) and the second receiving hydraulic cylinder (250″) are connected by a belt (260) to a pulley (270) arranged to rotate with alternating movement of the receiving hydraulic cylinders (250′, 250″).

12. 10. The system for remote actuation of an articulation mechanism according to claim 9, wherein the first transmission hydraulic cylinder and the second transmission hydraulic cylinder are connected by a belt to a pulley arranged to be rotated by the first actuator and the second actuator, generating relative positional variation between the transmission hydraulic cylinders.

13. 2. The system (10) for remote actuation of an articulated mechanism according to claim 1, wherein the actuation unit (11) comprises at least two actuation groups (100), and the system (10) is arranged to actuate at least two mechanical joints (200).

14. 14. The system (10) for remote actuation of an articulation mechanism according to claims 5 and 13, wherein the at least two voice coil actuators (110) are stacked on top of each other to share the same magnetic field.

15. 2. The system (10) for remote actuation of an articulation mechanism according to claim 1, further comprising a switching system (16) arranged to enable alternate connection of actuation groups (100) to the hydraulic lines (151, 152) of at least two mechanical joints (200).

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