При регистрации как электрофизиологических, так и неэлектрофизиологических параметров человека существует ряд внешних помех, накладывающих ограничения на проектируемые усилители биопотенциалов (УБП). Помехи по их виду, происхождению и влияниюна параметры полезного сигнала можно разделить на аддивные и мультипликативные. Аддивные помехи складываются с полезным сигналом и делятся на синфазные и разностные.

(далее…)

Категория: Научные статьи | Нет комментариев »

Powered orthotic devices can be used to restore mobility to the impaired user, and may thereby assist them in daily living tasks. An investigation is performed herein to examine the feasibility of a powered lower-limb orthotic in assisting the sit-to-stand task by 50% of the required torque. Feasibility is considered via simulation. A three-link sit-to-stand model, which is driven by kinematic data, is developed. Models of a Pneumatic Muscle Actuator and a DC motor are used to determine which of the two technologies can make a more appropriate contribution to the sit-to-stand task. Simulation revealed that both the Pneumatic Muscle Actuator and the DC motor are reasonable actuator choices, and neither limited the ability to achieve 50% torque assistance. The ability to assist the task was, however, limited by the ability to derive a control signal for the actuator from the user-orthotic interface. It was concluded that the user-orthotic interface requires further investigation. It was also found that while both actuator technologies are suitable for contributing 50% of the required torque, the Pneumatic Muscle Actuator is preferable due to its ability to scale to greater torques.

(далее…)

Категория: Научные статьи | Нет комментариев »

A normal working hand is one of the most important features for independence in an individual’s life. The human dependence on fully functioning hands is highlighted most when these integral tools of the body are hindered in some way. The loss of hand function results in a severe compromise of the ability to feed and care for oneself, and limits one’s participation in work, social and family life (Scott and Peckham 1995). There are many injuries or conditions that can result in the loss of hand function. These include paralysis (from central or peripheral nerve injuries), swelling, joint stiffness, pain, burns, scarring or broken bones. For individuals recovering from such conditions, vigilant, appropriate and effective therapy of the hands can significantly improve the outcome of the healing process and the restoration of hand function (Hunter, Mackin et al. 1995). Prior to the prescription of appropriate therapy, comprehensive assessment of hand condition is necessary. Furthermore, ongoing assessment during the course of the applied therapy can ensure the treatment will continue to be appropriate and provide optimal benefits to the patient. In addition, during the recovery process and where no further improvements can be made to the hand, there are technologies available that can improve and function.

(далее…)

Категория: Научные статьи | Нет комментариев »

We describe three bipedal robots that are designed and controlled based on principles learned from the gaits of passive dynamic walking robots. This paper explains the common control structure and design procedure used to determine the mechanical and control parameters of each robot. We present this work in the context of three robots: Denise, the Delft pneumatic biped, R1, a highly backdrivable electric biped, and R2, a hydraulic biped. This work illustrates the application of passive dynamic principles to powered systems with significant control authority.

(далее…)

Категория: Научные статьи | Нет комментариев »

Energetic autonomy of a hydraulic-based mobile field robot requires a power source capable of both electrical and hydraulic power generation. While the hydraulic power is used for locomotion, the electric power is used for the computer, sensors and other peripherals. An internal combustion engine was used as the prime mover due to the high energy density of gasoline. The primary specification for this hybrid Hydraulic-Electric Power Unit (HEPU) is that it must output constant pres-sure hydraulic power and constant voltage electric power. An on-board computer uses a pressure sensor and a speed sensor to regulate the pressure and voltage by modulating a hydraulic solenoid valve and an engine throttle. The speed regulation also results in a system noise with predictable frequency band which allows for optimal muffler design. A novel characteristic of this power source is its cooling system in which hydraulic fluid is used to cool the engine cylinders.

(далее…)

Категория: Научные статьи | Нет комментариев »