Human–Robot Collaboration Using Sequential Recurrent Convolution Network Based Dynamic Face Emotion

The proposed sequential recurrent convolution network (SRCN) includes two parts: one convolution neural network (CNN) and a sequence of long short-term memory (LSTM) models. The CNN is to achieve the feature vector of face emotion or speech command. Then, a sequence of LSTM models with the shared weight reflects a sequence of inputs provided by a (pre-trained) CNN with a sequence of input sub-images or spectrograms corresponding to face emotion and speech command, respectively. Simply put, one SRCN for dynamic face emotion recognition (SRCN-DFER) and another SRCN for wireless speech command recognition (SRCN-WSCR) are developed. The proposed approach not only effectively tackles the recognitions of dynamic mapping of face emotion and speech command with average generalized recognition rate of 98% and 96.7% but also prevents the overfitting problem in a noisy environment. The comparisons among mono and stereo visions, Deep CNN, and ResNet50 confirm the superiority of the proposed SRCN-DFER. The comparisons among SRCN-WSCR with noise-free data, SRCN-WSCR with noisy data, and multiclass support vector machine validate its robustness. Finally, the human-robot collaboration (HRC) using our developed omnidirectional service robot, including human and face detections, trajectory tracking by the previously designed adaptive stratified finite-time saturated control, face emotion and speech command recognitions, and music play, validates the effectiveness, feasibility, and robustness of the proposed method.