Data Collection And Assisting Force Analysis Of Sit-to-Stand Transfer Assisting Robot

The family service robot is an important development direction of the robot research field. Sit-to-stand transfer assisting robot is a kind of new family service robot which appears in recent years. Rising from the seated position is an activity carried out by most people many times daily. The sit-to-stand transfer assisting robot introduced in this paper aims at assisting sit-to-stand movement in the daily life of elderly people. This kind of device provides power assistance to lighten the load of joints and help elderly people keep their balance during standing-up. According to the present station and the compare of domestic and international research in this field, this paper does the following work on the data collection and assisting strategy of sit-to-stand transfer assisting robot.Firstly, this paper presents a literature review including the analysis of the standing-up motion, biomechanical analysis and modeling of sit-to-stand task, and the designs of the robots that assist people accomplishing sit-to-stand movement.Secondly, a modified algorithm for automatic measurement of sit-to-stand movement with no marking is proposed. Using this algorithm, the sensors and markings on user's body are replaced by a single monocular camera. Human body joint point position and angle varieties can be obtained as input data for the calculation of joint torque under the situation in which artificial intervention and dependence on sensors are not needed.Finally, a reasonable improvement about the assisting force analysis is made in the strategy of lightening the joint burden. Aiming at the characteristics and distinguishes between the assistive strategy that lightens joint torque and the assistive strategy that keeps body equilibrium, a fuzzy system is built up, which has one input and two outputs. With the inclination of thigh from level direction in the sit-to-stand movement for input, the weights of two kinds of assistive strategies in the whole rising process for outputs, this fuzzy system is used for helping customer lighten joint burden and keep body stability in the whole sit-to-stand process.