On the kinematic design of anthropomorphic lower limb exoskeletons and their matching movement

Abstract

The lower limb exoskeleton is a wearable device for assisting medical rehabilitation. A classical lower limb exoskeleton structures cannot precisely match the kinematics of the wearer’s limbs and joints in movement, so a novel anthropomorphic lower limb exoskeleton based on series–parallel mechanism is proposed in this article. Then, the human lower limb movements are measured by an optical gait capture system. Comparing the simulation results of the series–parallel mechanism with the measured human data, the kinematics matching model at the hip joint is established. The results show that the kinematic matching errors in the X, Y, and Z directions are less than 2 mm. So, the proposed kinematics matching model is effective and the anthropomorphic series–parallel mechanism has a significant improvement in tracing the human positions at the hip joint.

A Review of Parallel Robots: Rehabilitation, Assistance, and Humanoid Applications for Neck, Shoulder, Wrist, Hip, and Ankle Joints

“…Figure 7a shows a lower-limb exoskeleton based on the series-parallel mechanism. A 6-SPS parallel mechanism was employed to enhance the pelvis's capacity to move, thereby providing the lumbar spine joint with six degrees of freedom (DoF) [83].…”

“…A 3DoF hip favors models like 2-UPS/RRR [81,82] in rehabilitation and 4-RPS [84] in assistance robotics. Interestingly, the 6DoF hip primarily features the 6-UPS [80,83] configuration, evident in both the rehabilitation and assistance domains.…”

“…Dexterity: This is often measured using indices like the "manipulability measure", which is derived from the robot's Jacobian matrix[51,72,90,106]. Manipulability: This represents the ability of the robot to move in different directions[83,90]. Range of motion: This typically involves analyzing how well the robot can perform tasks that mimic human joint motions, such as rotations and translations[4,6,36,37,70,84,88].…”

Pedestrian Navigation Method Based on Machine Learning and Gait Feature Assistance

“…As shown in Figure 2, X h , Y h , Z h are the coordinates of human hip joint; X e , Y e , Z e are the coordinates of the end of the swinging shank in the fixed coordinate system; X b , Y b , Z b are the coordinates of the ankle joint in the generalized coordinate system; l 4 and l 5 are the length of shank and thigh of the swinging leg, respectively; d 4 and d 5 are the absolute distance of the inertial sensor mounted on thigh and shank from the Y-axis direction; the marks A, B, and C represent the inertial device mounted on the thigh, the foot, and the shank respectively. For the remaining definitions readers can refer to [24]. Based on the forward kinematics theory, the relative positional relationship between the thigh and the foot, is shown in Figure 2:…”

Social spider optimization algorithm for tuning parameters in PD-like Interval Type-2 Fuzzy Logic Controller applied to a parallel robot

“…10 Other parallel mechanisms are utilized for manufacturing anthropomorphic exoskeletons which matching and mimicking the real motions of some body parts, such as lower and upper limb exoskeletons, to be worn by elderly and disable persons. 11…”