Novel Design and Lateral Stability Tracking Control of a Four-Wheeled Rollator

Development of a Caterpillar-Type Walker for the Elderly People

A walker assists elderly people with age-related reduced walking ability and helps to improve stability and balance ability. However, if the general-type walker (GTW) is used on an uneven, obstacle, or sloped terrain, it may cause excessive muscle use and falls. Therefore, in this study, we developed a caterpillar-type walker (CTW) that elderly people can safely use in various terrains. Twelve elderly who were able to walk normally participated in the study. The activity of upper and lower extremity muscles, the number of obstacles overcome, and walking speed was compared and analyzed when using two types of walkers in uneven terrain, obstacle terrain, and sloped terrain. In addition, satisfaction with the use of these walkers was evaluated. When CTW was used, the activity of the muscles of the upper and lower extremities was significantly reduced compared to the use of GTW on all terrains. The walker developed in this study overcame obstacles of all heights, but the GTW failed to overcome obstacles starting from the 2 cm section. In terms of walking speed, when the CTW was used, the walking speed was higher than that of the GTW in uneven terrain and obstacle terrain. In satisfaction, there were significant differences in safety, durability, simplicity of use, comfort, and effectiveness. Through these results, it was confirmed that the CTW can efficiently and safely assist the elderly in walking on uneven terrain, obstacle terrain, and inclined terrain.

Application of Refined Kano’s Model to Shoe Production and Consumer Satisfaction Assessment

Many industries are labor-intensive and energy- and resource-consuming. A sustainable development plan is necessary for the industries as industrial structures have been changing recently. Taiwan’s shoe industry also has experienced such changes and requires a sustainable product development plan for continuous development. Therefore, this study aims to propose a new method by introducing a model of sustainable product development to facilitate the sustainable development of the industry. By taking air-cushioned casual shoe production as an example, this study suggested the refined Kano quality model for exploring the product attributes that improved the customers’ satisfaction. The refined Kano model that was established with interviews and questionnaire surveys was effective to define the product attributes that contributed to satisfying the customers and understanding their perception of product attributes. In the air-cushioned casual shoe production, the model found function, design, innovation, marketing, and service to be important for manufacturers to develop products with limited. It also suggested the priority be put on the attributes of high value-added quality, key quality, and potential quality. The model helped manufacturers decide which product attributes they need to invest in and develop. The relation of product attributes and consumer satisfaction for a sustainable product development model was also found by using the refined Kano model. The result of this study is expected to apply to various industries for establishing an appropriate sustainable product development model.

A Combined Use of TRIZ Methodology and Eco-Compass tool as a Sustainable Innovation Model

In recent years, there has been an increase in the adoption of quality tools by companies. As such, there has been a commitment to innovation by the organizations to obtain competitive advantages by the development of new products and technologies focused on the creation of economic value but also on delivering sustainability. This study aims to develop an application model of the inventive resolution theory in conjunction with the Eco-Compass ecological innovation tool, in order to allow solutions to be obtained systematically, and to present a performance increase of certain environmental parameters, promoting thus sustainable innovation. The case study research methodology is used to frame the research. The company under study is Nokia enterprise, located in Portugal, which offers a set of services related to telecommunications infrastructures. The unit of analysis is the department of transformation and continuous improvement, and the study illustrated the application of combined use of theory of inventive problem solving (TRIZ) and Eco-compass to develop innovative solutions systematically. The results show that it is possible to achieve innovation according to a certain level of established sustainable environmental parameters, while at the same time solving the identified inventive problem.

Adaptive Robust Force Position Control for Flexible Active Prosthetic Knee Using Gait Trajectory

Active prosthetic knees (APKs) are widely used in the past decades. However, it is still challenging to make them more natural and controllable because: (1) most existing APKs that use rigid actuators have difficulty obtaining more natural walking; and (2) traditional finite-state impedance control has difficulty adjusting parameters for different motions and users. In this paper, a flexible APK with a compact variable stiffness actuator (VSA) is designed for obtaining more flexible bionic characteristics. The VSA joint is implemented by two motors of different sizes, which connect the knee angle and the joint stiffness. Considering the complexity of prothetic lower limb control due to unknown APK dynamics, as well as strong coupling between biological joints and prosthetic joints, an adaptive robust force/position control method is designed for generating a desired gait trajectory of the prosthesis. It can operate without the explicit model of the system dynamics and multiple tuning parameters of different gaits. The proposed model-free scheme utilizes the time-delay estimation technique, sliding mode control, and fuzzy neural network to realize finite-time convergence and gait trajectory tracking. The virtual prototype of APK was established in ADAMS as a testing platform and compared with two traditional time-delay control schemes. Some demonstrations are illustrated, which show that the proposed method has superior tracking characteristics and stronger robustness under uncertain disturbances within the trajectory error in ± 0 . 5 degrees. The VSA joint can reduce energy consumption by adjusting stiffness appropriately. Furthermore, the feasibility of this method was verified in a human–machine hybrid control model.

Novel Design and Adaptive Fuzzy Control of a Lower-Limb Elderly Rehabilitation

Design and control of a lower-limb exoskeleton rehabilitation of the elderly are the main challenge for health care in the past decades. In order to satisfy the requirements of the elderly or disabled users, this paper presents a novel design and adaptive fuzzy control of lower-limb empowered rehabilitation, namely MOVING UP. Different from other rehabilitation devices, this article considers active rehabilitation training devices. Firstly, a novel product design method based on user experience is proposed for the lower-limb elderly exoskeleton rehabilitation. At the same time, in order to achieve a stable operation control for the assistant rehabilitation system, an adaptive fuzzy control scheme is discussed. Finally, the feasibility of the design and control method is validated with a detailed simulation study and the human-interaction test. With the booming demand in the global market for the assistive lower-limb exoskeleton, the methodology developed in this paper will bring more research and manufacturing interests.

Neural Approximation Enhanced Predictive Tracking Control of a Novel Designed Four-Wheeled Rollator

In the past few decades, the research of assistant mobile rollators for the elderly has attracted more and more investigation attention. In order to satisfy the needs of older people or disabled patients, this paper develops a neural approximation based predictive tracking control scheme to improve and support the handicapped through the novel four-wheeled rollator. Firstly, considering the industrial product theory, a novel Kano-TRIZ-QFD engineering design approach is presented to optimize the mechanical structure combined with humanistic care. At the same time, in order to achieve a stable trajectory tracking control for the assistant rollator system, a neural approximation enhanced predictive tracking control is discussed. Finally, autonomous tracking mobility of the presented control scheme has received sufficient advantage performance in position and heading angle variations under the external uncertainties. As the market for the medical device of the elderly rollators continues to progress, the method discussed in this article will attract more investigation and industry concerns.

Towards Model-Free Tool Dynamic Identification and Calibration Using Multi-Layer Neural Network

In robot control with physical interaction, like robot-assisted surgery and bilateral teleoperation, the availability of reliable interaction force information has proved to be capable of increasing the control precision and of dealing with the surrounding complex environments. Usually, force sensors are mounted between the end effector of the robot manipulator and the tool for measuring the interaction forces on the tooltip. In this case, the force acquired from the force sensor includes not only the interaction force but also the gravity force of the tool. Hence the tool dynamic identification is required for accurate dynamic simulation and model-based control. Although model-based techniques have already been widely used in traditional robotic arms control, their accuracy is limited due to the lack of specific dynamic models. This work proposes a model-free technique for dynamic identification using multi-layer neural networks (MNN). It utilizes two types of MNN architectures based on both feed-forward networks (FF-MNN) and cascade-forward networks (CF-MNN) to model the tool dynamics. Compared with the model-based technique, i.e., curve fitting (CF), the accuracy of the tool identification is improved. After the identification and calibration, a further demonstration of bilateral teleoperation is presented using a serial robot (LWR4+, KUKA, Germany) and a haptic manipulator (SIGMA 7, Force Dimension, Switzerland). Results demonstrate the promising performance of the model-free tool identification technique using MNN, improving the results provided by model-based methods.