Balance Hip-Knee Insights and Innovative Approaches with Sliding Mode Control

Abstract

This research investigates novel methodologies to analyze and enhance joint stability and control in human biomechanics, focusing on the Hip-Knee (HK) joint angles during single-leg stance (SLS) activity and applying Quasi Sliding Mode Control (QSMC) to a single-link biomechanical model. Identifying lower joint stability is critical, especially in older populations who are more likely to have falls and mobility limitations. This requires an understanding of joint dynamics under challenging conditions. This research aims to develop a non-invasive, cost-friendly method of identifying joint problems so that early intervention and treatment can prevent fall and instability in posture.. In the frst part of the research, pose estimation techniques were employed to analyze the hip-knee joint angles in young and elderly participants during an SLS activity. The results demonstrated a huge difference between the two age groups: younger individuals demonstrated stable and consistent joint angles, reflecting strong neuromuscular control and stable posture. The mean and standard deviation values were obtained:(107.14±5, 96.42±7) for both hips and (36.76±7, 44.30±4)for both knees from one of the young participants. These values are in line with the expected joint angles(110 to 120 degrees for the hip and 45 to 60 degrees for the knee) and show stability in results In contrast, the elderly group showed significant fluctuations and deviations in joint angles, often leading to moments of instability. The results from one of the elderly participants show a high level of variability and low mean values for both hips and knees: (65.42±77, 85±76.67) and (4.15±10.8, 7±18), respectively. These findings explain the difference in participant results and pose estimation’s potential as a diagnostic tool for identifying individuals at risk of joint-related issues, providing a non-invasive alternative to traditional imaging methods like MRI scans. These early detection results can prevent instability in their posture and prevent further joint issues. The second part of the research emphasizes the utilization of QSMC to a single link biomechanical model. This controlling technique allows us to analyze the stability of a body under multiple disturbances now QSMC was chosen for its robustness and effectiveness. Now chattering is a common issue in traditional sliding mode control techniques so to eliminate it we use QSMC which uses continuous law. The results confirmed the effectiveness of QSMC in maintaining stability under perturbations, with a significant reduction in input torque results (130Nm). However, the study also identified a trade-off, as the reduction in chattering led to an increase in settling time (2-3 Sec). Despite this, the overall performance of QSMC was better in comparison to other techniques for nonlinear systems, offering precise, stable, and efficient control.