Control automático de un exoesqueleto de marcha para pacientes con discapacidad motora

El objetivo de esta tesis es desarrollar una estrategia de control multivariable para el movimiento de un exoesqueleto de marcha. El propósito del exoesqueleto es asistir la caminata de un sujeto con discapacidad motora. En este trabajo se modela la dinámica multicuerpos del sistema sujeto exoesqueleto. El modelo de la dinámica multicuerpos es construido en SimMechanics de Matlab. El modelado y la simulación de la caminata incluye dos fases de operación: apoyo simple y apoyo doble. La dinámica de sistema sujeto-exoesqueleto tiene características no lineales, por tanto el modelo es linealizado alrededor de puntos de equilibrio dentro de cada fase de operación. Para la aproximación lineal del sistema se sintonizan controladores PI Vectorial, LQR y GPI. Los controladores permiten realizar el seguimiento de una trayectoria de referencia, garantizando la estabilidad del sistema a lo largo de toda la trayectoria de marcha. Este trabajo evalúa el seguimiento de trayectorias, rechazo de perturbaciones y variación de parámetros. Las evaluaciones de los controladores se realizan en el sistema no lineal construido en el modelo multicuerpos. Los resultados permiten concluir que los controladores GPI tienen el mejor desempeño para cada fase de apoyo, además tienen desempeño robusto a perturbaciones de alta frecuencia en la entrada de control y a variación de parámetros del sujeto.Abstract. The objective of this work is to develop a multivariable control to drive a gait exoskeleton. The purpose of the exoskeleton is to assist a person with walking disabilities. In this work the multibody dynamics model of both the person and the exoskeleton is developed. The model is built in SimMechanics of Matlab. The gait simulation consists of two operation stages: single support and double support. The dynamic of the person-exoskeleton is a nonlinear system, for that reason the model is linearized in a equilibrium point in each operation stages. With the linear approximation the PI Vectorial, LQR and GPI controllers are designed. The controllers allow to make tracking of trajectories with the warranty of that the system is stable and has robust performance. Trajectory tracking, disturbance rejection, and system parameter variations are evaluated. The results demonstrate that the GPI controllers to single and double support have the best performance and robustness indexes.Maestrí

Active Disturbance Rejection Control based on Generalized Proportional Integral Observer to Control a Bipedal Robot with Five Degrees of Freedom

An Active Disturbance Rejection Control based on Generalized Proportional Integral observer (ADRC with GPI observer) was developed to control the gait of a bipedal robot with five degrees of freedom. The bipedal robot used is a passive point feet which produces an underactuated dynamic walking. A virtual holonomic constraint is imposed to generate online smooth trajectories which were used as references of the control system. The proposed control strategy is tested through numerical simulation on a task of forward walking with the robot exposed to external disturbances. The performance of ADRC with GPI observer strategy is compared with a feedback linearization with proportional-derivative control. A stability test consisting on analyzing the existence of limit cycles using the Poincaré's method revealed that asymptotically stable walking was achieved. The proposed control strategy effectively rejects the external disturbances and keeps the robot in a stable dynamic walking

Robust compound control of dynamic bipedal robots

This paper presents a robust compound control strategy to produce a stable gait in dynamic bipedal robots under random perturbations. The proposed control strategy consists of two interactive loops: an adaptive trajectory generator and a robust trajectory tracking controller. The adaptive trajectory generator produces references for the robot controlled joints without a-priori knowledge of the terrain features and minimizes the effects of disturbances and model uncertainties during the gait, particularly during the support-leg exchange. The trajectory tracking controller is a non-switching robust multivariable generalized proportional integral (GPI) controller. The GPI controller rejects external disturbances and uncertainties faced by the robot during the swing walking phase. The proposed control strategy was evaluated on the numerical model of a five-link planar bipedal robot with one degree of under-actuation, four actuators, and point feet. The results showed robust performance and stability under external disturbances and model parameter uncertainties on uneven terrain with uphills and downhills. The stability of the gait was proven through the computation of a Poincaré return map for a hybrid zero dynamics with uncertainties (HZDU) model, which shows convergence to a bounded neighborhood of a nominal orbital periodic behavior

Hybrid disturbance rejection control of dynamic bipedal robots

This paper presents a disturbance rejection control strategy for hybrid dynamic systems exposed to model uncertainties and external disturbances. The focus of this work is the gait control of dynamic bipedal robots. The proposed control strategy integrates continuous and discrete control actions. The continuous control action uses a novel model-based active disturbance rejection control (ADRC) approach to track gait trajectory references. The discrete control action resets the gait trajectory references after the impact produced by the robot’s support-leg exchange to maintain a zero tracking error. A Poincaré return map is used to search asymptotic stable periodic orbits in an extended hybrid zero dynamics (EHZD). The EHZD reflects a lower-dimensional representation of the full hybrid dynamics with uncertainties and disturbances. A physical bipedal robot testbed, referred to as Saurian, is fabricated for validation purposes. Numerical simulation and physical experiments show the robustness of the proposed control strategy against external disturbances and model uncertainties that affect both the swing motion phase and the support-leg exchange

Automatic Stabilization of a Riderless Bicycle using the Active Disturbance Rejection Control Approach

[ES] Este trabajo propone una estrategia de Control por Rechazo Activo de Perturbaciones (ADRC), usando observadores extendidos de perturbación, para estabilizar una bicicleta en movimiento, sin conductor y con una velocidad de avance variable. Aunque la bicicleta tiene una dinámica inestable y no lineal alrededor de su posición vertical, que puede modelarse como un sistema Lineal de Parámetros Variantes (LPV) dependientes de la velocidad, el diseño del controlador usa un modelo simplificado de parámetros concentrados invariantes en el tiempo y una velocidad nominal constante. El esquema ADRC agrupa las discrepancias entre el modelo simplificado y la planta, junto con las perturbaciones externas en una señal aditiva unificada, que es estimada a través del observador y realimentada mediante una ley de control lineal para rechazarla. La efectividad de la estrategia es validada mediante una co-simulación entre ADAMS y MATLAB, la cual exhibe un alto desempeño y robustez sobre un modelo dinámico virtual de la bicicleta, sometida a perturbaciones externas severas y variaciones de parámetros.[EN] This work proposes an ADRC (Active Disturbance Rejection Control) strategy by disturbance extended observers to stabilize a moving riderless bicycle with a variant forward speed. Although the bicycle has an unstable and non-linear dynamics when in its upright position, which can be modeled as a LPV (Linear-Parameter-Varying) system that depends on the forward speed, a simplified time-invariant and lumped-parameter model, with an nominal constant forward speed is used in the controller design. ADRC scheme groups discrepancies between the simplified model and the plant, with external disturbances into an equivalent additive unified disturbance signal at input, which is estimated via the observer and rejected through a linear control law. The effectiveness of this strategy is validated by a co-simulation between ADAMS and MATLAB, which exhibits a high performance and robustness in a virtual dynamic model of the bicycle, submitted to severe external disturbances and parameter variations. Baquero-Suárez, M.; Cortes-Romero, J.; Arcos-Legarda, J.; Coral-Enriquez, H. (2017). Estabilización Automática de una Bicicleta sin Conductor mediante el Enfoque de Control por Rechazo Activo de Perturbaciones. Revista Iberoamericana de Automática e Informática industrial. 15(1):86-100. https://doi.org/10.4995/riai.2017.8832OJS86100151Ai-Buraiki, O., Thabit, M. B., Jun 2014. Model Predictive Control Design Approach for Autonomous Bicycle Kinematics Stabilization. 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Science 332 (6027), 339-342. https://doi.org/10.1126/science.1201959Kooijman, J. D. G., Schwab, A. L., Meijaard, J. P., May 2008. Experimental Validation of a Model for the Motion of an Uncontrolled Bicycle. Multibody System Dynamics 19 (1), 115-132. https://doi.org/10.1007/s11044-007-9050-xLam, P. Y., Sep 2011. Gyroscopic Stabilization of a Kid-Size Bicycle. In: 2011 IEEE 5th International Conference on Cybernetics and Intelligent Systems (CIS). pp. 247-252. https://doi.org/10.1109/ICCIS.2011.6070336Lewis, F. L., Popa, L. X. D., 2008. Optimal and Robust Estimation, with an Introduction to Stochastic Control Theory, 2nd Edition. CRC Press, Ch. 3, pp. 151-204.Limebeer, D. J. N., Sharp, R. S., Oct 2006. Bicycles, Motorcycles, and Models. IEEE Control Systems 26 (5), 34-61. https://doi.org/10.1109/MCS.2006.1700044Meijaard, J., Papadopoulos, J. M., Ruina, A., Schwab, A., 2007. Linearized Dynamics Equations for the Balance and Steer of a Bicycle: a Benchmark and Review. 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Predictors of clinically significant quality of life impairment in Parkinson’s disease

COPPADIS Study Group.Quality of life (QOL) plays an important role in independent living in Parkinson’s disease (PD) patients, being crucial to know what factors impact QoL throughout the course of the disease. Here we identified predictors of QoL impairment in PD patients from a Spanish cohort. PD patients recruited from 35 centers of Spain from the COPPADIS cohort from January 2016, to November 2017, were followed up during 2 years. Health-related QoL (HRQoL) and global QoL (GQoL) were assessed with the 39-item Parkinson’s disease Questionnaire (PDQ-39) and the EUROHIS-QOL 8-item index (EUROHIS-QOL8), respectively, at baseline (V0) and at 24 months ± 1 month (V2). Clinically significant QoL impairment was defined as presenting an increase (PDQ-39SI) or decrement (EUROHIS-QOL8) at V2 ≥ 10% of the score at baseline (V0). A comparison with a control group was conducted for GQoL. GQoL did not change significantly in PD patients (N = 507; p = 0.686) or in the control group (N = 119; p = 0.192). The mean PDQ-39SI was significantly increased in PD patients (62.7 ± 8.5 years old; 58.8% males; N = 500) by 21.6% (from 16.7 ± 13 to 20.3 ± 16.4; p < 0.0001) at V2. Ninety-three patients (18.6%) presented a clinically significant HRQoL impairment at V2. To be younger (OR = 0.896; 95% CI 0.829–0.968; p = 0.006), to be a female (OR = 4.181; 95% CI 1.422–12.290; p = 0.009), and to have a greater increase in BDI-II (Beck Depression Inventory-II) (OR = 1.139; 95% CI 1.053–1.231; p = 0.001) and NMSS (Non-Motor Symptoms Scale) (OR = 1.052; 95% CI 1.027–1.113; p < 0.0001) total scores from V0 to V2 were associated with clinically significant HRQoL impairment at the 2-year follow-up (Hosmer–Lemeshow test, p = 0.665; R 2 = 0.655). An increase in ≥5 and ≥10 points of BDI-II and NMSS total score at V2 multiplied the probability of presenting clinically significant HRQoL impairment by 5 (OR = 5.453; 95% CI 1.663–17.876; p = 0.005) and 8 (OR = 8.217; 95% CI, 2.975–22.696; p = 0.002), respectively. In conclusion, age, gender, mood, and non-motor impairment were associated with clinically significant HRQoL impairment after the 2-year follow-up in PD patients.Mir P. has received honoraria from AbbVie, Abbott, Allergan, Bial, Merz, UCB and Zambon and have received grants from the Spanish Ministry of Economy and Competitiveness [PI16/01575] co-founded by ISCIII (Subdirección General de Evaluación y Fomento de la Investigación) and by Fondo Europeo de Desarrollo Regional (FEDER), the Consejería de Economía, Innovación, Ciencia y Empleo de la Junta de Andalucía [CVI-02526, CTS-7685], the Consejería de Salud y Bienestar Social de la Junta de Andalucía [PI-0437-2012, PI-0471-2013], the Sociedad Andaluza de Neurología, the Jacques and Gloria Gossweiler Foundation, the Fundación Alicia Koplowitz, the Fundación Mutua Madrileña.Peer reviewe

Non-motor symptom burden in patients with Parkinson's disease with impulse control disorders and compulsive behaviours : results from the COPPADIS cohort

The study was aimed at analysing the frequency of impulse control disorders (ICDs) and compulsive behaviours (CBs) in patients with Parkinson's disease (PD) and in control subjects (CS) as well as the relationship between ICDs/CBs and motor, nonmotor features and dopaminergic treatment in PD patients. Data came from COPPADIS-2015, an observational, descriptive, nationwide (Spain) study. We used the validated Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale (QUIP-RS) for ICD/CB screening. The association between demographic data and ICDs/CBs was analyzed in both groups. In PD, this relationship was evaluated using clinical features and treatment-related data. As result, 613 PD patients (mean age 62.47 ± 9.09 years, 59.87% men) and 179 CS (mean age 60.84 ± 8.33 years, 47.48% men) were included. ICDs and CBs were more frequent in PD (ICDs 12.7% vs. 1.6%, p < 0.001; CBs 7.18% vs. 1.67%, p = 0.01). PD patients had more frequent previous ICDs history, premorbid impulsive personality and antidepressant treatment (p < 0.05) compared with CS. In PD, patients with ICDs/CBs presented younger age at disease onset, more frequent history of previous ICDs and premorbid personality (p < 0.05), as well as higher comorbidity with nonmotor symptoms, including depression and poor quality of life. Treatment with dopamine agonists increased the risk of ICDs/CBs, being dose dependent (p < 0.05). As conclusions, ICDs and CBs were more frequent in patients with PD than in CS. More nonmotor symptoms were present in patients with PD who had ICDs/CBs compared with those without. Dopamine agonists have a prominent effect on ICDs/CBs, which could be influenced by dose

Mechatronics Design of a Gait-Assistance Exoskeleton for Therapy of Children with Duchenne Muscular Dystrophy

This paper presents a mechatronics design of a gait-assistance exoskeleton for therapy in children with Duchenne muscular dystrophy (DMD). This type of muscular dystrophy is a severe condition that causes muscle wasting, which results in a progressive loss of mobility. Clinical studies have shown the benefits of physical therapy in prolonging the mobility of patients with DMD. However, the therapy sessions are exhaustive activities executed by highly qualified rehabilitation personnel, which makes providing appropriate treatment for every patient difficult. This paper develops a mechatronics design of a gait-assistance exoskeleton to automate therapy sessions. The exoskeleton design uses adaptable mechanisms to adjust the device to the patient’s needs and includes the design of a series-elastic actuator to reduce the effects of nonalignment of the rotation axis between the exoskeleton and the patient. A mathematical dynamic hybrid model of the exoskeleton and a child’s body is developed using anthropometry of a population of six-year-old children. The hybrid model is used to design a nonlinear control strategy, which uses differential geometry to perform feedback linearization and to guarantee stable reference tracking. The proposed control law is numerically validated in a simulation to evaluate the control system’s performance and robustness under parameter variation during therapy with trajectory-tracking routines

Non-motor symptoms burden, mood, and gait problems are the most significant factors contributing to a poor quality of life in non-demented Parkinson's disease patients: Results from the COPPADIS Study Cohort

[Objective] To identify factors related to a poor health-related and global quality of life (QoL) in a cohort of non-demented Parkinson's disease (PD) patients and compare to a control group.[Methods] The data correspond to the baseline evaluation of the COPPADIS-2015 Study, an observational, 5-year follow-up, multicenter, evaluation study. Three instruments were used to assess QoL: (1) the 39-item Parkinson's disease Questionnaire (PDQ-39), (2) a subjective rating of global QoL (PQ-10), and (3) the EUROHIS-QOL 8-item index (EUROHIS-QOL8). Multiple linear regression methods were used to evaluate the direct impact of different variables on these QoL measures.[Results] QoL was worse in PD patients (n = 692; 62.6 ± 8.9 years old, 60.3% males) than controls (n = 206; 61 ± 8.3 years old, 49.5% males): PDQ-39, 17.1 ± 13.5 vs 4.4 ± 6.3 (p < 0.0001); PQ-10, 7.3 ± 1.6 vs 8.1 ± 1.2 (p < 0.0001); EUROHIS-QOL8, 3.8 ± 0.6 vs 4.2 ± 0.5 (p < 0.0001). A high correlation was observed between PDQ-39 and Non-Motor Symptoms Scale (NMSS) (r = 0.72; p < 0.0001), and PDQ-39 and Beck Depression Inventory-II (BDI-II) (r = 0.65; p < 0.0001). For health-related QoL (PDQ-39), non-motor symptoms burden (NMSS), mood (BDI-II), and gait problems (Freezing Of Gait Questionnaire [FOGQ]) provided the highest contribution to the model (β = 0.32, 0.28, and 0.27, respectively; p < 0.0001); whereas mood and gait problems contributed the most to global QoL (PQ-10, β = -0.46 and −0.21, respectively; EUROHIS-QOL8, β = -0.44 and −0.23, respectively).[Conclusions] QoL is worse in PD patients than in controls. Mood, non-motor symptoms burden, and gait problems seem to be the most relevant factors affecting health-related and global perceived QoL in non-demented PD patients.Peer reviewe