Research On Hip Automatic Protection System Based On New Trigger Device And Pre-impact Fall Detection

The wearable hip automatic protection system can effectively protect the hip joint when the elderly falls.There are researching on this at home and abroad,but similar products need to use exclusive gas cylinders and replacement of new gas cylinders need to be returned to the factory,The pre-impact fall detection is complex and difficult to apply to embedded platforms.In order to solve the above shortcomings,the Shenzhen Institute of Advanced Technology of the Chinese Academy of Sciences designed a mechanically triggered automatic protection system based on the standard gas cylinder and the standard threaded interface in the early stage,but the airbag still has a small protection area due to a single gas cylinder;the pre-impact fall detection is accurate low rate,high false alarm rate and other shortcomings.In order to solve the above problems,a set of hip automatic protection system based on the new trigger device and fall warning algorithm has been designed.The effective intervention time of the human body falling from gait instability to the human body touching the ground is 514.5ms on average.Therefore,the pre-impact fall detection successfully warns the time to fall and the total time for the trigger device to deflate the compressed gas cylinder cannot exceed 514.5ms,in order to increase larger protection area requires more compressed gas.Therefore,the protection system can play a more important role in the fall of the elderly by shortening the warning time of the preimpact fall detection and releasing the compressed gas,and releasing more compressed gas.On the one hand,compared with the single cylinder trigger device,the designed new micromechanical bidirectional trigger device can simultaneously puncture two 8 gram carbon dioxide compressed gas cylinders,increasing the amount of compressed gas released without increasing the deflation time.The trigger device's the response time is 103.45 ms,the execution time is185.65 ms,and the total deflation time is 289.10 ms,which makes the protection range of the capsule to the hip larger.On the other hand,designing a pre-impact fall detection based on data statistics has a short warning time,a low false alarm rate and a high accuracy rate.Through the real-time analysis of human motion data,the class-like fall actions are filtered according to the real-time combined acceleration,and then the real fall actions in the class-like fall actions are warned according to the real-time attitude angle.The fall warning algorithm has an average warning time of 142 ms,and the fall warning lead time It is 372.5ms,which can allow sufficient time for the new micro-mechanical two-way trigger device to deflate the gas cylinder.The accuracy rate for daily actions is 96.09%,and the accuracy rate for fall actions is 96.67%.The system is triggered by a physical and mechanical method.Compared with chemical blasting or hot-melt methods,the system has the characteristics of low cost and safe and convenient replacement of consumables.The pre-impact fall detection based on statistical methods has high accuracy and low false alarm rate,and the intervention time of the system on the fall action is an average of 431.1ms,which can provide effective protection to the hip before the human body falls.After the elderly wear it,perform a 30 s posture calibration.After the posture calibration is over,they can move freely.The sensor collects human movement information in real time and can recognize 8 daily actions and 3 fall actions.When the fall warning subsystem warns of a fall when it is about to happen,send a PWM pulse width signal to the human body protection airbag subsystem to turn the electric steering gear,drive the micro-mechanical two-way trigger device to release 16 gram of carbon dioxide compressed gas,so that the compressed gas can be charged into the foldable integrated bionic capsule at a high speed.The human body spreads out in front of the ground to form a cushion with a thickness of 65 mm and an area of 0.23 square meters,which provides effective protection to the human body.At the same time,indoor positioning is performed through Wi Fi or base station,and GPS/Beidou are used for outdoor positioning,which will cause the wearer to fall.The location and time and other information of the camera are sent to the guardian via GPRS remote communication.The new generation of wearable hip automatic protection system was exhibited at the China International High-tech Achievement Fair and China International Import Expo,and was widely praised.