Intelligent System for Automatic Recognition and Evaluation of Speech Commands Wojciech Kacalak and Maciej Majewski Koszalin University of Technology, Department of Mechanical Engineering Raclawicka 15-17, 75-620 Koszalin, Poland {wojciech.kacalak, maciej.majewski}@tu.koszalin.pl Abstract. In this paper, a natural language interface is presented which consists of the intelligent mechanisms of human identification, speech recognition, word and command recognition, command syntax and result analysis, command safety assessment, technological process supervision as well as human reaction assessment. In this paper, a review is carried out of selected issues with regards to recognition of speech commands in natural language given by the operator of the technological device. A view is offered of the complexity of the recognition process of the opera- tor’s words and commands using neural networks made up of a few layers of neurons. The paper presents research results of speech recognition and automatic recognition of commands in natural language using artificial neural networks. 1 Intelligent Two-Way Speech Communication If the operator is identified and authorized by the natural language interface in Fig. 1, a command produced in continuous speech is recognized by the speech recognition module and processed in to a text format. Then the recognised text is analysed by the syntax analysis subsystem. The processed command is sent to the word and command recognition modules using artificial neural networks to recognise the command, which is sent to the effect analysis subsystem for analysing the status corresponding to the hypothetical command execution, con- secutively assessing the command correctness, estimating the process state and the technical safety, and also possibly signalling the error caused by the operator [4]. The command is also sent to the safety assessment subsystem for assessing the grade of affiliation of the command to the correct command category and making corrections. The command execution subsystem signals commands ac- cepted for executing, assessing reactions of the operator, defining new parame- ters of the process and run directives. The subsystem for voice communication produces voice commands to the operator [5]. 2 Recognition of Commands in Natural Language In the automatic command recognition system shown in Fig. 2a, the speech sig- nal is processed to text and numeric values with the module for processing voice I. King et al. (Eds.): ICONIP 2006, Part I, LNCS 4232, pp. 298–305, 2006. c  Springer-Verlag Berlin Heidelberg 2006