Analysis and control of a parallel lower limb based on pneumatic artificial muscles

Abstract

Most robots that are actuated by antagonistic pneumatic artificial muscles are controlled by various control algorithms that cannot adequately imitate the actual muscle distribution of human limbs. Other robots in which the distribution of pneumatic artificial muscle is similar to that of human limbs can only analyze the position of the robot using perceptual data instead of rational knowledge. In order to better imitate the movement of a human limb, the article proposes a humanoid lower limb in the form of a parallel mechanism where muscle is unevenly distributed. Next, the kinematic and dynamic movements of bionic hip joint are analyzed, where the joint movement is controlled by an observer-based fuzzy adaptive control algorithm as a whole rather than each individual pneumatic artificial muscle and parameters that are optimized by a neural network. Finally, experimental results are provided to confirm the effectiveness of the proposed method. We also document the role of muscle in trajectory tracking for the piriformis and musculi obturator internus in isobaric processes.

Investigating the Effect of a Mechanism Combined with a Speed-Increasing Gear and a Pneumatic Artificial Muscle

“…The speed-increasing gearbox is basically composed of a large (input) and small (output) gears, each having different teeth number, as shown in Figure 2. Let the teeth number of the input large gear and output small gear, input torque and rotational angle, output torque and rotation angle be Figure 2, and T o and φ o could be represented as (1). Here, Z o /Z i means a reduction ratio R g of the gearbox.…”

“…Elements and actuators that are used in the devices have a profound effect on the compliance and lightness of the whole device. These include springs, pneumatic artificial muscles (PAMs) [1][2][3][4][5][6][7][8][9][10][11], magnetorheological (MR) dampers [12][13][14], shape memory alloys (SMAs) [15][16][17], soft pneumatic actuators (SPAs) [18], and dielectric elastomer actuators (DEAs) [19]. Research and development of these components and devices that employ them are widely conducted.…”

Bionics Design of Artificial Leg and Experimental Modeling Research of Pneumatic Artificial Muscles

“…Since the NN technique does not require any prior knowledge of a model of the process, it is widely used in industry to estimate process variables in real time for monitoring and control [10]. Jiang et al proposed a humanoid lower limb in the form of a parallel mechanism where the muscle was unevenly distributed by PAM [11]. Liu et al proposed a bionic shoulder joint robot with a spherical hinge which was driven by a group of PAM [12].…”

HUmanoid Robotic Leg via pneumatic muscle actuators: implementation and control

“…A small number of human-inspired PMA-actuated leg setups have been proposed in the past fifteen years, with most related research addressing the structural design, modeling and control problems for undertaking motions mainly in the sagittal plane [6][7][8][9][10][11][12][13][14][15][16]. Specifically, [6] presented a robotic leg design with the ability to perform hip and knee 1-DOF motions, with antagonistic pairs of PMAs connected through tendons on the target joints, while the ankle joint remained passive.…”

“…Different design approaches were incorporated in the foot design for analyzing running capabilities in [12], while alternative placement for the PMA pairs in the hip-knee formations has been considered in [13,14]. The most recent efforts included the development and control of a robotic knee-ankle setup, which enabled ankle movements in both sagittal and planes by incorporating PMAs in a synergistic fashion [15,16]. The utilized technique resembled the muscle formations in the human leg, while each PMA was connected to the metallic structure via tendon-inspired wires.…”