Fall Detection And Protection System Based On MEMS Inertial Sensor

In view of China's aging society is not rich first old features,the health of the elderly as an important social component of society will also have a huge impact on the country.Falls is an important factor that threatens the safety of the elderly and increases the social burden.Therefore,it is important to study the development of human fall warning and its protective equipment to reduce the damage caused by the fall.The system uses STM32F405 RG as the main control chip,MPU9150 nine-axis sensor acts as a MEMS inertial sensor,SIM900 A as GSM / GPRS communication module,UM220 as GPS / BD positioning module,through the combination of these modules constitute a fall detection under the machine node.We use the MEMS inertial sensor to collect the human motion data,and combine the characteristics of the acceleration and attitude angle of the fall from the human body to fall down the experimental data to develop the fall detection algorithm based on the joint acceleration and attitude angle threshold.So that the system can fall before the fall of the human body before the fall warning,MCU to GPS module to collect the fall of the geographical location information extracted after adding to the SMS format,in the fall through the GSM / GPRS module sent out,Inform the guardian that the occurrence of the fall has been detected.The host computer system can also display9-axis data waveform in real time,with both storage and playback functions.After completing the design of the fall detection node,connect the node to the control steering gear to drive a hip joint airbag,consisting of a falling test and its protection system.When the system's fall detection algorithm detects that the fall is about to occur,the MCU sends a signal to the steering gear to drive the needle on the steering gear to pierce the cylinder,so that the Department of the airbag in the human body fast inflatable,protect the human hip in the human body,to reduce the impact of the face of the human body when falling.The core of the fall detection device is the fall detection algorithm,and the fall detection algorithm needs to be based on a large number of fall experiments.The data of the fall data in the fall experiment was collected by the human inertial sensor,And then the original data processing of the accelerometer and gyroscope raw data,and use the digital filter fusion algorithm to carry out the attitude calculation.And then theattitude of the human body to calculate the acceleration,attitude angle data and analysis of the fall of the combined speed,attitude angle threshold comparison,in order to achieve the detection of falling behavior.And then in the laboratory to wear the system in the waist to carry out the fall experiment,Experiments show that the various parts of the system work properly,fall detection accuracy of more than 98%,and the airbag can be completely opened before the fall,play a role in protecting the human body.