A robotic knee unit

Abstract

The invention relates to a robotic knee unit (10) suitable for use by amputees or humanoid robots, comprising at least one elastic member (30) capable of storing energy thereon to produce torque in the knee joint while mimicking the movement of the leg during daily activities, and at least one first motor (40) connected to one end of the elastic member (30) to enable energy to be stored on said elastic member (30) and to compress the elastic member (30).

Description

[0001] A ROBOTIC KNEE UNIT

[0002] TECHNICAL FIELD

[0003] The invention relates to a robotic knee unit for use with amputees or humanoid robots, comprising at least one elastic member capable of storing energy to generate torque at the knee joint, and at least one first motor to provide energy storage, while simulating walking movement.

[0004] BACKGROUND

[0005] Various prostheses are being developed with the developing technology to replace the function of the missing limbs of people who have lost limbs due to congenital or later illness, accident, etc. The main objectives in the development of prostheses are to produce lightweight, cost- effective, and accessible products that can fully replace the function of the missing limb.

[0006] The knee is one of the parts of the leg prosthesis that needs to be configured most realistically so that the amputee can move comfortably. When the gait movement is considered as a cycle, it basically consists of stepping on the ground, pushing off the ground, and swing movements. An elastic member is included in the knee prosthesis to generate the pushing force in order to realize the pushing phase from the ground in this cycle. The elastic member stores energy in itself and provides thrust during the pushing phase from the ground.

[0007] Passive prostheses converge to gait kinematics but are inadequate for movements that require positive net force, such as stair climbing. Powered prostheses have been developed to overcome this. The torque required in this type of prosthesis is generated with the support of the actuator unit. Units with series-elastic or parallel-elastic actuators instead of direct-drive motors are less energy efficient, heavy, and complex.

[0008] Application No. WO2014032775A1 in the literature, relates to a powered prosthesis. The object of the invention is to create a prosthesis that enables a better gait and easy stair climbing. According to the embodiment, the device can reproduce physiological knee torques during stair ascent and descent and modulate its apparent stiffness within a physiological range. As the power in the knee joint is mainly consumed during walking on level ground and stair descent, a device according to the invention may also include a damper in parallel to reduce energy consumption in these activities.

[0009] As a result, the above-mentioned issues have made it necessary to innovate in the related technical field.

[0010] BRIEF DESCRIPTION OF THE INVENTION

[0011] The present invention relates to a robotic knee unit to overcome the above-mentioned disadvantages and to bring new advantages to the relevant technical field.

[0012] An object of the invention is to provide a robotic knee unit in which the control of the elastic member is enhanced during the swing movement in the gait cycle.

[0013] Another object of the invention is to provide a robotic knee unit with a lightweight structure.

[0014] In order to achieve all the above-mentioned objects and all the objects that will arise from the detailed description below, the present invention is a robotic knee unit suitable for use for amputees or humanoid robots, comprising at least one elastic member capable of storing energy thereon to generate torque in the knee joint while imitating walking movement, and at least one first motor connected to one end of the elastic member to provide energy storage on said elastic member and to compress the elastic member. Accordingly, its novelty is that it comprises at least one moment arm (80) coupled to the elastic member (30), said moment arm (80) being coupled to at least one second motor (50) for controlling the rotational speed during movement relative to the elastic member (30). Thus, controlled stepping and swing movement is achieved by controlling the elastic member from both ends. Additionally, a lightweight, compact, and simple structure is achieved. Therefore, an easy-to-control, low-cost, and convenient robotic knee joint is obtained.

[0015] A possible embodiment of the invention is characterized in that the moment arm is connected at one end to a power output point of the second motor and at the other end to at least one crank arm, said crank arm is connected at one end to an elastic member, the moment arm and the crank arm comprise at least one first connection joint allowing the moment arm and the crank arm to be rotatably connected to each other, the crank arm comprises at least one second connection joint allowing the crank arm to be rotatably connected to the elastic member. A possible embodiment of the invention is characterized in that it comprises at least one cover serving as a housing for the second motor. This ensures that the second motor is isolated from the external environment.

[0016] BRIEF DESCRIPTION OF THE FIGURES

[0017] Figure 1 shows a representative perspective view of the robotic knee unit of the invention.

[0018] Figure 2 shows a representative perspective view of the robotic knee unit of the invention from another angle.

[0019] DETAILED DESCRIPTION OF THE INVENTION

[0020] In this detailed description, the subject matter of the invention is explained only by means of examples that will not have any limiting effect for a better understanding of the subject matter.

[0021] Figure 1 shows a representative perspective view of the robotic knee unit (10) of the invention. Accordingly, the said robotic knee unit (10) is configured to imitate human leg movements during walking, climbing stairs and hills, sitting, and rising. The robotic knee unit is a prosthesis suitable for use by people who have been amputated below the knee. The robotic knee unit (10) of the invention can also be a suitable robotic limb to be placed in the leg parts of humanoid robots.

[0022] The robotic knee unit (10) comprises a body (20). The said body (20) provides structural integrity for the robotic knee unit (10). The body (20) has a cylindrical shape in a possible embodiment of the invention. Accordingly, the body (20) has a first end (21 ) and a second end (22) and extends between said first end (21 ) and said second end (22). The first end (21 ) is part of the robotic knee unit (10) proximal to the floor. Accordingly, a prosthetic foot can be connected to the first end (21 ). The second end (22) is the part of the robotic knee unit (10) far from the floor. Accordingly, the second end (22) can be connected to the thigh of an amputee or a humanoid robot that is to use the robotic knee unit (10). The second end (22) is provided with at least one socket (23) connection to enable the robotic knee unit (10) to be connected to said thigh portion.

[0023] The role of the robotic knee unit (10) is to imitate a human's gait, stair, and hill-climbing, sittingstanding, and stepping movement most realistically. The main object according to the invention is to enable the robotic knee unit (10) to be functional in situations requiring positive net power, such as climbing stairs. When the gait movement is considered as a cycle, it basically consists of stepping on the ground, pushing off the ground, and swing movements. Stepping on the ground is the interval between the moment when the heel of the foot first touches the ground and the moment when the sole is completely on the ground. Pushing off the ground is the interval between the moment when the sole is completely on the ground and the moment when the toe is completely off the ground. The swing interval describes the oscillating movement below the knee for the next step.

[0024] The robotic knee unit (10) comprises at least one elastic member (30). The said elastic member (30) can stretch in the direction of a first axis (I). The said first axis (I) is essentially in the extension direction of the body (20). The elastic member (30) has a compressible structure. The elastic member (30) is essentially located in the body (20). According to a preferred embodiment of the invention, the elastic member (30) is a spring.

[0025] The elastic member (30) is connected to at least one first motor (40) at its first end (21 ). Said first motor (40) generates the drive to compress the elastic member (30). This allows energy to be stored on the elastic member (30) for the stance phase. The robotic knee unit (10) comprises at least one second motor (50). The said second motor (50) generates a torque of a predetermined magnitude at the knee joint. There is at least one cover (24) around the second motor (50) which serves as housing.

[0026] The first motor (40) and the second motor (50) and the elastic member (30) are connected at both ends by a drive member. The second motor (50) here allows the movement of the elastic member (30) to be more controlled, while ensuring that the proper magnitude of torque is generated at the knee joint. The second motor (50) also enables the robotic knee unit (10) to perform a controlled swing movement during the swing phase.

[0027] The robotic knee unit (10) comprises at least one moment arm (80) and at least one crank arm (90) to perform all these functions. Said moment arm (80) and said crank arm (90) are connected to each other at each end by at least one first connection joint (60). Said first connection joint (60) comprises at least one pin (61 ). The said pin (61 ) allows the two elements to be connected to each other. The crank arm (90) is connected to the elastic member (30) at the other end. The crank arm (90) is connected to the elastic member (30) by at least one second connection joint (70). The moment arm (80) is capable of 360° rotation.

[0028] The drive from the second motor (50) is output as a rotational drive from at least one power output point (51 ). The moment arm (80) is connected at the other end to the said power output point (51 ) in order to realize rotational movement with the drive from the second motor (50). Accordingly, the moment arm (80) rotates around the power output point (51 ) with the drive it receives from the power output point (51 ). The crank arm (90) also rotates around the second connection joint (70) to the extent permitted by the connection between it and the moment arm (80). As a result, the second connection joint (70) moves sequentially in both directions in the line of the first axis (I). For this movement, the moment arm (80) and the crank arm (90) make a rotational movement relative to the first connection joint (60).

[0029] In the swing phase of the gait cycle, when the moment arm (80) rotates so that the first connection joint (60) approaches the second end (22), the second connection joint (70) moves linearly in the first axis (I) towards the first end (22). As a result, the elastic member (30) is compressed. In the meantime, the first motor (40) compresses the elastic member (30) to store energy. Furthermore, the moment arm (80) and crank arm (90) structure prevents the elastic member (30) compressed by the first motor (40) from restricting the swing movement of the knee. The stored energy is partially released in the stance phase of movements such as climbing stairs, climbing hills, or standing up, 'so that the required net positive power can be provided in an energy-efficient manner.

[0030] The rotational movement around the power output point (51 ), as well as the movement of the moment arm (80) and the crank arm (90) in conjunction with each other, enables the robotic knee unit (10) to perform a controlled swing. On the other hand, the second motor (50) in the robotic knee unit (10) provides a controlled extension of the elastic member (30). In the absence of the second motor (50), there will be no control over the speed of the moment arm (80). Since elastic energy tends to release rapidly, the speed of the moment arm (80) will pass from maximum to minimum in a quite short time. In this context, the second motor (50) controls the speed of the moment arm (80) to adjust the moment around the knee joint to the intended value and direction.

[0031] The robotic knee unit (10) includes at least one control unit. The said control unit is the unit that detects and interprets the signals for the control of the robotic knee unit (10). The controller can predetermine the amount of torque needed for the stepping. This ensures that the elastic member (30) is compressed to the proper extent. The signals required for the activation of the robotic knee unit (10) can be detected by the sensor or sensors on the robotic knee unit (10).

[0032] The robotic knee unit (10) comprises at least one battery (not shown in the figures) to power the first motor (40) and the second motor (50). In contrast to the structures in the present art, the workload of the first motor (40) is reduced with the robotic knee unit (10) of the invention. This allows the first motor (40) to be selected smaller than the structures of the present art. In addition, the said battery can also have a lower capacity and therefore a lower volume and mass. This provides a lightweight structure for the robotic knee unit (10), allowing for long-term use.

[0033] In possible embodiments of the invention, the robotic knee unit (10) may be manufactured from materials such as carbon fiber, ABS, and TPU. In this context, the robotic knee unit (10) is suitable for additive manufacturing. These material groups are also used to realize a lightweight robotic knee unit (10) in a compact structure.

[0034] The protection scope of the invention is specified in the appended claims and certainly cannot be limited to what is described in this detailed description for illustrative purposes. It is clear that those skilled in the art can come up with similar embodiments in the light of the foregoing without departing from the main theme of the invention.

[0035] REFERENCE NUMBERS GIVEN IN THE FIGURES

[0036] 10 Robotic Knee Unit

[0037] 20 Body

[0038] 21 First End

[0039] 22 Second End

[0040] 23 Socket

[0041] 24 Cover

[0042] 30 Elastic Member

[0043] 40 First Motor

[0044] 50 Second Motor

[0045] 51 Power Output Point

[0046] 60 First Connection Joint

[0047] 61 Pin

[0048] 70 Second Connection Joint

[0049] 80 Moment Arm

[0050] 90 Crank Arm

[0051] (I) First Axis

Claims

CLAIMS1. A robotic knee unit (10) suitable for use by amputees or humanoid robots, comprising at least one elastic member (30) that can store energy on it to produce torque at the knee joint while imitating the movement of the leg during daily activities, at least one first motor (40) coupled to one end of the elastic member (30) to provide energy storage on said elastic member (30) and compression of the elastic member (30), characterized in that it comprises at least one moment arm (80) coupled to the elastic member (30), said moment arm (80) being coupled to at least one second motor (50) for controlling the rotational speed during its movement relative to the elastic member (30).

2. A robotic knee unit (10) according to Claim 1 , characterized in that the moment arm (80) is connected at one end to a power output point (51 ) of the second motor (50) and at the other end to at least one crank arm (90), said crank arm (90) being connected at one end to an elastic member (30), that it comprises at least one first connection joint (60) enabling the moment arm (80) and the crank arm (90) to be rotationally connected to each other, that it comprises at least one second connection joint (70) for rotationally free engagement of the crank arm (90) with the elastic member (30).

3. A robotic knee unit (10) according to Claim 1 , characterized in that it comprises at least one cover (24) which serves as a housing for the second motor (50).

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