Recognition to weightlifting postures using convolutional neural networks with evaluation mechanism

For modern sport training, critical posture recognition of athletes can be helpful for athlete training. This paper proposes convolutional neural networks using a two-stage evaluation mechanism to recognize four critical postures of a weightlifter, that is, force releasing, knee flexion, knee extension and highest point. Using the proposed convolutional neural networks classify images and extract image features. Meanwhile, a two-stage evaluation mechanism is adopted to calculate the scores of image features, based on the calculated scores, the four critical postures can be accurately recognized. Experimental results show that the accuracy of our method is 92.85% in the recognition of the four critical postures, which defeats the competitive methods in critical posture recognition. Moreover, the training time of the proposed method linearly augments along with the increasing of data volume, that is, non-exponential growth, consequently, our method can be applied to large-scale image datasets. We demonstrate that the two-stage mechanism can calculate the scores of image features independently of specific scenarios, which assist neural networks improve classification capabilities. Moreover, using the two-stage mechanism can simplify the designed complexity of neural network architectures, thus reducing the training parameter of neural networks in the process of critical posture recognition.