Two Kinds Of Human Lower Limb Posture Detection Technology And Its Comparative Study

Body posture is an important source of the most intuitive information about human body. It not only reflects the person's balance and intentions, but also shows his/her state of health and mind. The information provides more accurate data for the physiological basic science, more wonderful user experience for virtual reality and reliable and scientific support for rehabilitation instruction. Nowadays,Kinect sensor which have low cost and special function, take the fancy of more and more people. Meanwhile, polyaxis inertial sensor have been widely used in wearable detection device.These sensors are very important for the improving walking rehabilitation and auxiliary robots' ability to perceive the posture of lower limb.Therefore this paper presents two methods for lower limb detection, the first one is based on Kinect sensor, the second one is based on polyaxis inertial sensor. We do comparative experiments on different lower limb gesture to find out the advantage and disadvantage of each method.First, it introduce the main funtion of Kinect sensor, that is loading the color and depth image.Based on the main funcion and use the image processing, it can detect the marker and get the depth, and turn two-dimensional pixel coordinates into three- dimensional coordinates system.To effectively solve the detection of lower limb posture, this paper offer a method based on Kinect sensor.Then, this paper offer a wearable detection device which based on polyaxis inertial sensor.By using the polyaxis inertial sensor to caculate the coordinate of ankles, knees and hip joints in three- dimensional coordinates system, so that we can realize the detection of lower limb posture.At last, we do comparision of the experimental results with real data, verify the detection method based on the Kinect sensor to the method based on the polyaxis inertial sensor, the overall deviation is small,but the real-time effect is poorer.Furthermore, method based on the polyaxis inertial sensor is more accurate.This two methods are expected to be used to detect the tread gesture of the assistant user.