Iterative learning based output feedback control for electro-hydraulic loading system of a gait simulator

Guo, Qinyang; Shi, Guanglin; Wang, Dongmei; He, Changyu; Hu, Jie; Wang, Wei

doi:10.1016/j.mechatronics.2018.07.011

Cited by 17 publications

(12 citation statements)

References 37 publications

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“…This process would be repeated until the tibia loading force could converge to the target curve through several iterations. [23] Ground reaction forces were synchronously collected using a force plate system of 1000Hz ( FP4060-15-2000Bertec USA), and kinematic data was recorded (100Hz) using seven cameras (Qualisys (Mocap Camera -Miqus M3 ) Motion Capture Systems, Sweden) which were positioned close to the specimens.…”

Section: Methodsmentioning

confidence: 99%

“…[21] We have developed a cadaveric gait simulator with 6 DOF of tibia in a physiological way that moved the cadaver foot while keeping the force plate static. Furthermore, the peak of vertical GRF achieved physiological value ranging from 1.1BW and1.3BW [22][23] . The aim of this work was to study the foot bony motion and joints move in a gait cycle with this foot and ankle gait simulator.…”

Section: Introductionmentioning

confidence: 99%

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In vitro study of foot bone kinematics via a custom-made cadaveric gait simulator

Zhu

Wang

Yuan

et al. 2020

Preprint

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Background: Quantifying detailed kinematics of the intrinsic foot bone during gait is crucial for understanding biomechanical functions of the foot complex musculoskeletal structure and making appropriate surgery decisions.Research question: The purpose of this experiment is to measure bones kinematic of the normal foot in a gait cycle via a custom-made cadaveric gait simulator.Methods：In this experiment, we used a custom-made 6 degrees of freedom (DOF) of robotic gait simulator simulating normal human gait to measure the 3-dimensional (3D) kinematics of tibia, calcaneus, cuboid, navicular, medial cuneiform, first metatarsal, and fifth metatarsal through six cadaveric feet.Results: The results showed that the kinematic of the intrinsic foot bones in the stance phase of the gait was successfully quantified using a custom-made robotic gait simulator. During walking stance, the joints in the medial column of foot had less movement than those in the lateral column. And during the later portion of stance, no rotational cease was observed in the movement between navicular and cuboid, calcaneocuboid joint, or cuneonavicular joint.Conclusion: This study described foot bone motion using a biomechanically near-physiological gait simulator with 6 DOF of the tibia. The kinematic data helps to clarify previous descriptions of several joints kinematics that are difficult to study in vivo. The methodology also provides a platform for researchers to explore more invasive foot biomechanics under dynamic and near-physiologic conditions.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

In vitro study of foot bone kinematics via a custom-made cadaveric gait simulator

Zhu

Wang

Yuan

et al. 2020

Preprint

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“…In the hydraulic cylinder motion process, the external leakage of oil is a trace amount, so it is ignored. The hydraulic cylinder flow continuity equations are given by [9]…”

Section: Valve-controlled Asymmetric Hydraulic Cylindermentioning

confidence: 99%

“…The first is axis synchronization, one of the issues that almost all parallel devices will encounter [8]. The second challenge involves the parameter uncertainty [9], unknown dead-zones [10], and unknown external disturbances of the EHPS [11]. These will lead to the control system to fail.…”

Section: Introductionmentioning

confidence: 99%

Active Disturbance Rejection Position Synchronous Control of Dual-Hydraulic Actuators with Unknown Dead-Zones

Wang

Zhao

Liu

et al. 2020

Sensors

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In this paper, an integrated control strategy of position synchronization control for dual-electro-hydraulic actuators with unknown dead-zones is proposed. The unified control scheme consists of two parts: One is adaptive dead-zone inverse controllers of each hydraulic actuator to offset the unknown dead-zones. The other is the linear active disturbance rejection controller (LADRC) for position synchronization error. First, the model of the electro-hydraulic proportional position control system (EPPS) was identified by the forgetting factor recursive least square (FFRLS) algorithm. Next, the model reference dead-zone inverse adaptive controller (MRDIAC) was developed to compensate for the delay of actuator response caused by unknown proportional valve dead-zones. Meanwhile, the validity of the adaptive law was proven by the Lyapunov theory. Therefore, the position control accuracy of each hydraulic actuator is guaranteed. Besides, to improve the precision of position synchronization control of dual-hydraulic actuators, a simple and elegant synchronous error-based LADRC was adopted, which applies the total disturbances design concept to eliminate and compensate for motion coupling rather than cross-coupling technology. The performance of the proposed control solution was investigated through extensive comparative experiments based on a hydraulic test platform. The experimental results successfully demonstrate the effectiveness and practicality of the proposed method.

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“…Up to now, some studies based on the output feedback control have been applied to DC Motors [12], hydraulic actuators [14,15], flight actuation system [16] and hydraulic loading system [17]. However, since the dynamics of pneumatic systems are highly nonlinear due to gas compressibility, the aforementioned output feedback controllers cannot be applied directly to the pneumatic systems.…”

Section: Introductionmentioning

confidence: 99%

Output feedback motion control of pneumatic servo systems with desired compensation approach

Wei-ping

Meng

2020

J Braz. Soc. Mech. Sci. Eng.

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In this study, an output feedback control strategy for the pneumatic asymmetric cylinder is established by integrating a robust controller with the proposed desired compensation adaptive law and extended sliding mode observer (ESMO). Specifically, in order to attenuate the parametric uncertainties, a desired compensation indirect-type estimation method, based on physical model and desired system states, is designed to achieve estimates of model parameters, and the parameter estimation error can be regarded as part of the lumped uncertainties. Since only displacement signal is available, both the unmeasured system states and lumped uncertainties are estimated by the proposed ESMO, and the global stability is guaranteed by the presented robust control law. As a result, structured (i.e., parametric uncertainties) and unstructured (i.e., lumped uncertainties such as unmodeled dynamics, external disturbance and parameter estimation error) uncertainties can be handled and compensated, respectively, in one controller. The comparative experimental results indicate that the prescribed tracking trajectory can be achieved by the proposed controller in the presence of time-varying uncertainties.

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Iterative learning based output feedback control for electro-hydraulic loading system of a gait simulator

Cited by 17 publications

References 37 publications

In vitro study of foot bone kinematics via a custom-made cadaveric gait simulator

In vitro study of foot bone kinematics via a custom-made cadaveric gait simulator

Active Disturbance Rejection Position Synchronous Control of Dual-Hydraulic Actuators with Unknown Dead-Zones

Output feedback motion control of pneumatic servo systems with desired compensation approach

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