A robot upper-luggage training device based on a parallel elastic actuator

Abstract

The present invention discloses a robot trunk training device based on a parallel elastic actuator, including a stiffness control module structure, a variable stiffness module structure, and a connection module structure. The parallel elastic actuator combines a variable stiffness module and a stiffness control module, which serve as passive and active inputs, respectively, and generate output torque on the trunk through an output link. The input torque of the connection module comes from the output connecting rod and is transmitted to the trunk through a four-bar linkage. Compared with other medical devices, the robot trunk training device provided by the present invention combines the output connecting rod with a customized cam profile design, and changes the stiffness of the variable stiffness module through the stepper motor in the stiffness control module, so that the supporting force can be actively controlled. For real human applications, a connector and a wiring harness structure can be used to connect the link to a rehabilitation robot, and the rehabilitation robot can be fixed on a movable platform such as a wheelchair or a fixed platform such as a treadmill as needed.

Description

Technical Field

[0001] The present invention belongs to the field of medical rehabilitation robots, and in particular relates to a robot luggage loading training device based on a parallel elastic actuator. Background Art

[0002] Rehabilitation robots are medical robots that use robotic technology to guide rehabilitation medicine and are commonly used in the rehabilitation treatment of patients with limb injuries. Their overall purpose is to replace or supplement the care of rehabilitation therapists in treating limb injuries and streamline the one-on-one treatment process of conventional rehabilitation. With technological advancements and increasing medical needs, the application of rehabilitation robots in rehabilitation medicine is becoming increasingly widespread. While mechanical systems for limb rehabilitation are relatively mature, rehabilitation equipment for patients with spinal and trunk injuries is relatively scarce. These patients require specialized support and assistance during their rehabilitation process to help them regain trunk stability and mobility.

[0003] In rehabilitation training, most current trunk rehabilitation devices do not deal well with problems such as joint dislocation, lack of force adaptive assistance, and rigid human-computer interaction. These devices focus on the movement of the waist joint. These devices use rigid actuators such as DC motors and widely used PID-based position controllers. Force adaptive assistance is usually not mentioned in the controllers of current relay support devices. The reference position or force controller is usually predefined by the researchers, regardless of the patient's recovery status and muscle strength status, that is, active support capabilities. Therefore, excessive guidance often occurs and reduces training results. Summary of the Invention

[0004] The purpose of this invention is to solve the above problems and provide a new type of rehabilitation robot. By optimizing the structure and transmission device, a robot upper trunk training device based on parallel elastic actuator is designed. In this work, the robot is designed to assist in the rehabilitation training of the upper torso based on the waist joint.

[0005] To address the above technical issues, the present invention provides a robotic luggage loading training device based on a parallel elastic actuator, characterized by comprising a variable stiffness module, a stiffness control module, and a frame. The frame comprises a base, a tower, and a variable stiffness module mounting frame. The stiffness control module and variable stiffness module are mounted within a right-angle load-bearing column and the variable stiffness module mounting frame. The tower and variable stiffness module mounting frame are mounted on the base and tower. First, a single-degree-of-freedom four-bar linkage is introduced to connect the patient's torso, indirectly transmitting torso motion to the rehabilitation robot. This indirect connection between the torso and the rehabilitation robot avoids joint misalignment between the waist joint and the robot joints. Furthermore, the kinematic constraints of the linkage can be used to accurately estimate the position of the human joints. Second, the variable stiffness module and stiffness control module can adjust the rehabilitation robot's support level and provide feedback and force adaptation assistance, aiming to promote friendly human-robot interaction. The parallel elastic actuator mechanism in this work is formed by a planetary gear system and integrates passive support from the elastic component with a rigid actuator. To reduce the rigidity requirement and improve control efficiency, the support torque of the passive element must be designed to match the required torque. Ultimately, a customizable cam-spring mechanism can be used to secure the human torso in various postures within the rehabilitation robot's workspace. The rehabilitation robot's support level, as well as the stiffness level (torque-angle relationship) of the parallel elastic actuator, can be modulated in real time using the parallel elastic actuator's rigid actuator. Furthermore, if the adjustment is performed at the beginning of training, force-adaptive assistance is semi-active, in which the rehabilitation robot's support force is primarily passively generated by the parallel elastic actuator's elastic component and modulated by the rigid actuator.

[0006] Preferably, the base includes an ultra-short base frame load-bearing beam, a short base frame load-bearing beam, a long base frame load-bearing beam, a base frame fixing piece, and a bottom plate. The ultra-short base frame load-bearing beam, the short base frame load-bearing beam, and the long base frame load-bearing beam are fixedly connected in sequence with the base frame fixing piece, and then the bottom plate is fixed thereon.

[0007] Preferably, the tower body includes a right-angle load-bearing medium, a base frame fixing member I, a right-angle load-bearing long, a right-angle load-bearing fixing member, a right-angle load-bearing short, a right-angle load-bearing ultra-short, a right-angle load-bearing spring, and a base frame fixing member II. The right-angle load-bearing medium and the right-angle load-bearing spring are fixed to the base plate using the base frame fixing member I and the base frame fixing member II. The right-angle load-bearing long is fixed to the right-angle load-bearing medium using the right-angle load-bearing fixing member. The right-angle load-bearing short and right-angle load-bearing ultra-short are fixed to the right-angle load-bearing spring using the right-angle load-bearing fixing member.

[0008] Preferably, the stiffness control module includes a spring-mounted lower base, a spring base, a spring, a spring mount, a spring mount upper base, a linear bearing, a roller, a roller, a potentiometer output, a pin, a potentiometer instrument, and a potentiometer. The spring is mounted to the spring mount, the spring base is mounted to the spring mount, and the entire assembly is mounted to the spring mount lower base and the spring mount upper base. The linear bearing is then installed between the spring mount upper base and the spring mount for axial positioning. The roller and roller are placed in the through-hole above the spring mount, and the pin is passed through in sequence and secured with a spring retaining ring. The potentiometer output is secured to the potentiometer instrument, the potentiometer instrument is mounted in the hole of the potentiometer, and the potentiometer output is screwed to the spring mount.

[0009] Preferably, the variable stiffness module fixing frame includes a spring side plate, a motor side fixing plate, an encoder baffle, and a human body side plate. The human body side plate, the spring side plate, the motor side fixing plate, and the encoder baffle are respectively matched one by one with the right-angle load-bearing through holes and fixedly connected with screws and nuts.

[0010] Preferably, the variable stiffness module includes a worm gear structure and a gear transmission device, wherein the worm gear structure and the gear transmission device are mounted on a fixed frame of the variable stiffness module, and the worm gear structure cooperates with the gear transmission device to form a worm gear.

[0011] Preferably, the worm gear structure includes an encoder, a motor, a worm support, a bearing I, and a worm. The encoder is installed on the motor, and then the motor and the worm support are fixed to the motor side fixing plate, and the bearing I is installed on the worm support, and finally the worm is installed on the motor.

[0012] Preferably, the gear transmission structure includes bearing II, a cantilever beam, bearing III, bearing IV, a fixed pinion, a gear ring, a pinion, a sun gear, a turbine support, bearing V, a turbine connecting rod, a turbine, and a cam. Bearing V is fixed to the turbine. The turbine support is then aligned with the four threaded holes of the turbine and screwed together. Finally, the gear ring is aligned with the four threaded holes of the turbine support and screwed together. The pinion and bearing II are passed through the pinion and fixed. Bearing II is fixed in the three through-holes of the cantilever beam, and finally, the bearing is installed in the center through-hole of the cantilever beam. The cam, turbine, turbine support, sun gear, gear ring, and cantilever beam are sequentially mounted to the turbine connecting rod, and the pinion is meshed with the sun gear and ring gear. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the exploded structure of a robot luggage training device based on a parallel elastic actuator according to the present invention;

[0014] Figure 2 Schematic diagram of the structural explosion of the stiffness control module of the present invention;

[0015] Figure 3 This is a schematic diagram of the explosion structure of the variable stiffness module of the present invention;

[0016] Figure 4 This is a schematic diagram of the exploded structure of the frame of the present invention;

[0017] Figure 5 This is a schematic diagram of the stiffness control module of the present invention;

[0018] Figure 6 Schematic diagram of the cam design principle of the present invention (a);

[0019] Figure 7 It is the principle diagram of the cam design of the present invention (b);

[0020] Figure 8 is a schematic diagram of the cam profile of the present invention;

[0021] Explanation of reference numerals: spring-fixed lower base (1), spring base (2), spring (3), spring fixed (4), spring-fixed upper base (5), linear bearing (6), roller (7), roller (8), potentiometer output (9), pin (10), potentiometer instrument (11), potentiometer (12), encoder (13), motor (14), worm support (15), bearing I (16), turbine (17), bearing II (18), cantilever beam (19), bearing III (20), bearing IV (21), pinion fixed (22), gear ring (23), pinion (24), sun gear (25), turbine support Support (26), bearing V (27), turbine connecting rod (28), turbine (29), cam (30), base frame load-bearing beam ultra-short (31), base frame load-bearing beam short (32), base frame load-bearing beam long (33), base frame fixing piece (34), right angle load-bearing middle (35), base frame fixing piece I (36), right angle load-bearing long (37), right angle load-bearing fixing piece (38), spring side plate (39), motor side fixing plate (40), encoder baffle (41), right angle load-bearing short (42), right angle load-bearing ultra-short (43), right angle load-bearing spring (44), human body side plate (45), base frame fixing piece II (46), bottom plate (47). DETAILED DESCRIPTION

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0023] like Figures 1 to 8 As shown, the present invention provides a robot luggage loading training device based on a parallel elastic actuator:

[0024] Figure 1 This is the general assembly drawing of the present invention:

[0025] First, a single-degree-of-freedom four-bar linkage is introduced to connect the patient's torso, indirectly transmitting the human torso's movements to the rehabilitation robot. This indirect connection between the human torso and the rehabilitation robot avoids joint misalignment between the waist joint and the robot's joints. Furthermore, the kinematic constraints of the linkage can be used to accurately estimate the positions of the human joints.

[0026] Secondly, through parallel elastic actuators, the rehabilitation robot's support level can be adjusted and feedback and force-adaptive assistance can be provided, aiming to provide friendly human-robot interaction. The parallel elastic actuator mechanism in this work is formed by a planetary gear system and integrates passive support from elastic components and rigid actuators. To reduce the rigidity requirements of the actuator and improve control efficiency, the support torque of the passive element needs to be designed to match the required torque.

[0027] Ultimately, a customizable cam-spring mechanism can be used to secure the human torso in various postures within the rehabilitation robot's workspace. The rehabilitation robot's support level, as well as the stiffness level (torque-angle relationship) of the parallel elastic actuator, can be modulated in real time using the parallel elastic actuator's rigid actuator. Furthermore, if the adjustment is performed at the beginning of training, force-adaptive assistance is semi-active, in which the rehabilitation robot's support force is primarily passively generated by the parallel elastic actuator's elastic component and modulated by the rigid actuator.

[0028] Figure 2 This is a schematic diagram of the structural explosion of the stiffness control module of the present invention:

[0029] The stiffness control module includes a spring-fixed lower base (1), a spring base (2), a spring (3), a spring fixation (4), a spring-fixed upper base (5), a linear bearing (6), a roller (7), a roller (8), a potentiometer output (9), a pin (10), a potentiometer instrument (11), and a potentiometer (12).

[0030] Install the spring (3) to the spring mount (4), then install the spring base (2) to the spring mount (4), and then install the entire assembly to the spring mount lower base (1) and the spring mount upper base (5). Install the linear bearing (6) between the spring mount upper base (5) and the spring mount (4) as an axial positioning device. Place the roller (7) and the wheel (8) in the through hole above the spring mount (4), and pass the pin (10) through it in sequence, securing it with a spring retaining ring. Secure the potentiometer output (9) to the potentiometer instrument (11), and install the potentiometer instrument (11) into the hole of the potentiometer (12). Secure the potentiometer output (9) to the spring mount (4) with screws.

[0031] Figure 3 This is a schematic diagram of the explosion structure of the variable stiffness module of the present invention:

[0032] The variable stiffness module includes an encoder (13), a motor (14), a worm support (15), a bearing I (16), a turbine (17), a bearing II (18), a cantilever beam (19), a bearing III (20), a bearing IV (21), a pinion fixing (22), a gear ring (23), a pinion (24), a sun gear (25), a turbine support (26), a bearing V (27), a turbine connecting rod (28), a turbine (29), and a cam (30).

[0033] Install the encoder (13) to the motor (14), then fix the motor (14) and the worm support (15) to the motor side fixing plate (40), and install the bearing I (16) to the worm support (15), and finally install the worm to the motor (14). Fix the bearing V (27) to the turbine (29), then match the turbine support (26) with the four threaded holes of the turbine (29) one by one and connect them with screws, and finally match the gear ring (23) with the four threaded holes of the turbine support (26) one by one and connect them with screws. Pass the pinion (24) and bearing II (18) through the pinion fixing (22), and fix the bearing II (18) in the three through holes of the cantilever beam (19), and finally install the bearing IV (21) in the center through hole of the cantilever beam (19). The cam (30), turbine (29), turbine support (26), sun gear (25), gear ring (23), and cantilever beam (19) are sequentially mounted on the turbine connecting rod (28), and the pinion (24) is engaged with the sun gear (25) and gear ring (23).

[0034] Figure 4 This is a schematic diagram of the explosion structure of the framework of the present invention:

[0035] The frame comprises a base frame load-bearing beam super short (31), a base frame load-bearing beam short (32), a base frame load-bearing beam long (33), a base frame fixing piece (34), a right-angle load-bearing middle (35), a base frame fixing piece I (36), a right-angle load-bearing long (37), a right-angle load-bearing fixing piece (38), a spring side plate (39), a motor side fixing plate (40), an encoder baffle (41), a right-angle load-bearing short (42), a right-angle load-bearing super short (43), a right-angle load-bearing spring (44), a human body side plate (45), a base frame fixing piece II (46), and a bottom plate (47).

[0036] The base frame load-bearing beam super short (31), the base frame load-bearing beam short (32), and the base frame load-bearing beam long (33) are sequentially connected using the base frame fixing piece (34), and then the bottom plate (47) is fixed thereon. The right-angle load-bearing middle (35) and the right-angle load-bearing spring (44) are fixed to the bottom plate (47) using the base frame fixing piece I (36) and the base frame fixing piece II (46). The right-angle load-bearing long (37) is fixed to the right-angle load-bearing middle (35) using the right-angle load-bearing fixing piece (38). The right-angle load-bearing short (42) and the right-angle load-bearing super short (43) are fixed to the right-angle load-bearing spring (44) using the right-angle load-bearing fixing piece (38). The human body side plate (45), the spring side plate (39), the motor side fixing plate (40), and the encoder baffle (41) are sequentially matched with the through holes of the right-angle load-bearing and are fixedly connected using screws and nuts.

[0037] Figures 6 to 8 Design schematic diagram for cam size:

[0038] The variable stiffness module size design uses a special cam profile design to match the reference torque and maintain the human torso in all postures within its workspace. The developed cam profile is divided into four regions: zero support region, force matching region, motion restriction region, and transition region. The coordinate system XoY is the reference frame of the cam, where o coincides with the center of the cam shaft and the axes are parallel to the global reference frame of XoY. The profile of the zero support region is the sector angle θ zs The arc has its center coinciding with o. Here, the spring of the variable stiffness module is not compressed and no output torque is generated. The sector angle is θ fm The contour of the force matching area is designed to provide support that can passively support the torso in all postures. mr The motion restriction zone generates greater resistance, causing the trunk to stop moving. The transition zone is the motion constraint and zero support area.

[0039] The working mode of the rehabilitation robot is related to the initial configuration of the cam roller follower mechanism. When the roller is initially placed at the junction of the zero support and force matching areas, that is, the starting configuration position, the rehabilitation robot operates in full support mode, so that the torso can be passively supported by the device without the patient's active torque. When the roller is initially placed at a certain position in the zero support area, no output torque is generated before the roller enters the force matching area, and the rehabilitation robot operates in partial support mode. In this mode, there is an area where the torso is allowed to move freely, called the free motion area of the torso, which can increase the training challenge. When the roller starts from the junction of the zero support and transition areas, that is, the extreme configuration position, if the motor does not move, the rehabilitation robot does not generate output torque.

[0040] When the motor rotates, the roller can move to different areas of the cam profile to adjust the output torque of the variable stiffness module. The cam of the variable stiffness module has three working areas: the zero support area, where the variable stiffness module outputs no torque; the force matching area, where the output torque-angle relationship is described above; and the motion limit area, where the variable stiffness module always outputs the maximum support torque. The output torque of the variable stiffness module in these areas can be

[0041]

[0042] where τ 可变刚度模块 (θ 凸轮 ) is the area given by the required output torque-angle relationship in the force matching area, θ zs and θ mr is the maximum value of the fan angle between the zero support area and the motion restriction area, max(τ 可变刚度模块 ) is to find τ 可变刚度模块 For the cam profile designed for this product, the fan shape of the zero support area and the motion restriction area is the same, that is, θ zs =θ mr =156.5°, the free range of motion of the patient’s torso can cover the entire working space of the torso (60.9°<θ<90°), which is 90° if the roller is initially placed on the LMTCON.

[0043] When the motors are not moving, the rehabilitation robot has three working modes.

[0044] If the roller is at the initial position when the trunk is upright, that is, when the initial cam angle θ 凸轮 =0°, when the trunk angle θ=90°, the variable stiffness module only works in the force matching area of the cam when the trunk moves in its workspace, and the rehabilitation robot provides all the required support torque, while the patient does not provide active support torque. It is fixed to the patient's torso, which is called the full support mode of the rehabilitation robot.

[0045] If the roller is at the initial cam angle θ 凸轮 =-θ zs =-156.5°, when the trunk angle θ = 90°, there is no torque provided by the variable stiffness module in the entire workspace of the trunk, which is called the zero support mode of the rehabilitation robot.

[0046] If the roller is in the supporting motion area of the cam, the initial cam angle is θ 凸轮= -78°. When the trunk angle θ = 90°, the trunk experiences a free motion region (75.3° ≤ θ ≤ 90°), where the roller is in the zero support region of the cam, followed by a partially supported motion region (60.9° < θ < 75.3°), where the roller is in the force matching region. Because the support torque of the rehabilitation robot always lies between the partially supported modes of the trunk, when the motor moves, both supported and unsupported motion regions are required within the entire trunk workspace. This mode is called a partially supported mode.

[0047] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and it should be understood that the scope of protection of the present invention is not limited to such specific descriptions and embodiments. Those skilled in the art can make various other specific variations and combinations based on the technical teachings disclosed in the present invention without departing from the essence of the present invention, and such variations and combinations are still within the scope of protection of the present invention.

Claims

1. A robot luggage loading training device based on a parallel elastic actuator, characterized by: The invention comprises a variable stiffness module, a stiffness control module and a frame, wherein the frame comprises a base, a tower body and a fixed frame for the variable stiffness module; the stiffness control module and the variable stiffness module are installed in a right-angle load-bearing length (37) and the fixed frame for the variable stiffness module; the tower body and the fixed frame for the variable stiffness module are installed on the base and the tower body; the base comprises an ultra-short base frame load-bearing beam (31), a short base frame load-bearing beam (32), a long base frame load-bearing beam (33), a base frame fixing member (34) and a bottom plate (47); the ultra-short base frame load-bearing beam (31), the short base frame load-bearing beam (32) and the long base frame load-bearing beam (33) are fixedly connected in sequence by the base frame fixing member (34), and then the bottom plate (47) is fixed thereon; the tower body comprises a right-angle load-bearing middle (35), a base frame fixing member The stiffness control module comprises a spring fixing lower base (1), a spring base (2), a spring (3), a spring fixing member (4), a spring fixing member (5), a spring fixing member (6), a spring fixing member (7), a spring fixing member (8), a spring fixing member (9), a spring fixing member (10), a spring fixing member (11), a spring fixing member (12), a spring fixing member (13), a spring fixing member (14), a spring fixing member (15), a spring fixing member (16), a spring fixing member (17), a spring fixing member (18), a spring fixing member (19), a spring fixing member (20), a spring fixing member (21), a spring fixing member (22), a spring fixing member (23), a spring fixing member (24), a spring fixing member (25), a spring fixing member (26), a spring fixing member (27), a spring fixing member (28), a spring fixing member (29), a spring fixing member (30), a spring fixing member (31), a spring fixing member (32), a spring fixing member (33), a spring fixing member (34), a spring fixing member (35), a spring fixing member (36), a spring fixing member (35), a spring fixing member (36), a spring fixing member (31), a spring fixing member (32), a spring fixing member (33), a spring fixing member (34), a spring fixing member (35), a spring fixing member (36), a spring fixing member (35), a spring fixing member (36), a spring fixing member (3 (4), spring fixed upper base (5), linear bearing (6), roller (7), roller (8), potentiometer output (9), pin (10), potentiometer instrument (11), potentiometer (12), install the spring (3) to the spring fixed (4), then install the spring base (2) to the spring fixed (4), and then install the whole to the spring fixed lower base (1) and the spring fixed upper base (5), and then install the linear bearing (6) between the spring fixed upper base (5) and the spring fixed (4) as axial positioning; place the roller (7) and roller (8) in the through hole above the spring fixed (4), and pass the pin (10) through it in sequence and fix it with a spring retaining ring; fix the potentiometer output (9) on the potentiometer instrument (11) The potentiometer instrument (11) is installed in the hole of the potentiometer (12), and the potentiometer output (9) is fixed to the spring fixing (4) with screws. The variable stiffness module fixing frame includes a spring side plate (39), a motor side fixing plate (40), an encoder baffle (41), and a human body side plate (45). The human body side plate (45), the spring side plate (39), the motor side fixing plate (40), and the encoder baffle (41) are sequentially matched with the right-angle load-bearing through holes and fixedly connected with screws and nuts. The variable stiffness module includes a worm gear structure and a gear transmission device. The worm gear structure and the gear transmission device are installed on the variable stiffness module fixing frame. The worm gear structure and the gear transmission are matched with the worm gear.

2. The robot luggage loading training device based on parallel elastic actuators according to claim 1, characterized in that: The worm gear structure comprises an encoder (13), a motor (14), a worm support (15), a bearing I (16), and a worm (17). The encoder (13) is mounted on the motor (14), and then the motor (14) and the worm support (15) are fixed to a motor side fixing plate, and the bearing I (16) is mounted on the worm support (15). Finally, the worm (17) is mounted on the motor (14).

3. The robot luggage loading training device based on parallel elastic actuators according to claim 1, characterized in that: The gear transmission structure includes bearing II (18), cantilever beam (19), bearing III (20), bearing IV (21), pinion fixed (22), gear ring (23), pinion (24), sun gear (25), turbine support (26), bearing V (27), turbine connecting rod (28), turbine (29), cam (30), fixing bearing V (27) to turbine (29), then aligning the four threaded holes of turbine support (26) with those of turbine (29) and connecting them with screws, and finally aligning the four threads of gear ring (23) with those of turbine support (26). The threaded holes correspond to each other one by one and are connected with screws; the pinion (24) and the bearing II (18) are passed through the pinion fixing (22), and the bearing II (18) is fixed in the three through holes of the cantilever beam (19). Finally, the bearing IV (21) is installed in the central through hole of the cantilever beam (19), and the cam (30), the turbine (29), the turbine support (26), the sun gear (25), the gear ring (23), and the cantilever beam (19) are installed to the turbine connecting rod (28) in sequence, and the pinion (24) is meshed with the sun gear (25) and the gear ring (23).

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