Design of Intelligent Vehicle for Distribution System EEased on Speech RecognitionLi

Design of Intelligent Vehicle for Distribution System EEased on Speech Recognition

 

Abstract—The paper presents a method of designing an intelligent vehicle for distribution system. The voice order of a human being operator can be recognized and transformed into digital information by iFlytek Input, which is installed on theAndroid smartphones as a mobile app. Moreover, based on the Bluetooth wireless communication technology, the digital information about voice order can be transmitted to the intelligent vehicle which is mainly made up of the Single Chip Microcomputer(SCM) MSP430F169. Code Shoppy Finally, the SCM will deal with the received information and acquire the key content to control Direct Current (DC) driving device, which can actuate the DC motor to accomplish all kinds of basic distribution assignments. Keywords-intelligent vehicle; single chip microcomputer; iFlytek input; bluetooth; DC motor  

ANALYSIS OF THE SYSTEM ARCHITECTURE

 For a distribution system, the warehousing area consists of the waiting area and the shelves area, which is displayed in the figure 1. The waiting area is used to park the intelligent vehicles, and the shelves area stores the goods. The shelves area is divided into six lines (A, B, C, D, E, F) and seven columns (1, 2, 3, 4, 5, 6, 7). Then, there are 42 shelves, and each shelf has a unique code, namely, A1, A2, ......, A7, B1, B2, ......, B7, ......, F1, F2, ......, F7. The black line shows the route of the smart vehicle from the waiting point to the black objective shelve. The control system of the distribution system is composed of the control terminal which deals with the speech recognition by the Android app and the execution terminal which carries out the specific orders by the intelligent vehicle. The control terminal can recognize the voice commands from all kinds of operators, which will guide the execution terminal to complete the distribution assignments. Furthermore, the working modes include the automatic and manual mode. The automatic mode deals with the conventional path by the vehicle itself, while the manual mode disposes the complex working situation by the operator. Two kinds of patterns can be switched by the voice orders at any time. Figure 1. The distribution area map In the first place, the operator issues the speech orders through the control terminal to confirm working mode. In the automatic mode, the operator will continue to send voice commands of the objective shelf code to the vehicle. According to the shelf code, the vehicle will automatically calculate and scheme the distribution path, which will direct the vehicle to transport the goods to the objective shelf. At last, the vehicle could discharge the goods and return to the waiting area in terms of the original path. In the manual mode, the operator can adjust the running path of the vehicle in real time by a series of voice orders, such as "forward", "backward", "left", "right", "stop" and so on. In order to realize the function of the intelligent system, the hardware system of it must be constructed firstly. And then each module type of the hardware system and the specific circuit connection between them must be confirmed. Ultimately, the design of the intelligent system will be finished based on the combination of the software and hardware system. 

THE HARDWARE SYSTEM 

The hardware system obtains and refines the voice messages from the operator, outputs the distribution 2017 3rd IEEE International Conference on Computer and Communications instructions to the DC motor and so forth. The structure of the hardware system is shown in the figure 2. As shown in the figure 2, the core controller is the Single Chip Microcomputer (SCM) MSP430F169, which can obtain the digital speech information from iFlytek Input by using the CC2541 chip of Bluetooth wireless communication module produced by Texas Instruments (TI). The digital information will be processed furtherly to get operational commands, which will be displayed on the LCD and be applied to control the running of the DC motor. As displayed in the figure 2, the hardware system is composed of iFlytek Input, the Bluetooth wireless communication module, the LCD module, the driving module for DC motor, the driving power, and the voltage converter. In the following sections, these modules will be described in detail. A.iFlytek Input Speech recognition is the process of refining speech signal and extracting its feature. The sound collected by the voice sensor is chaotic, there's no rules to follow, so it must be filtered out the noise and be amplified to extract the feature vector sequences of speech. Furthermore, compared with the characteristic variable sequence of the reference model library, the feature vector sequence can be obtained by a specific retrieval algorithm and acoustic modeling method (such as dynamic sequential structured method, artificial neural network and support vector machine (SVM) method) [2][3]. Based on that recognition theory, iFlytek Input provides a voice input mode, which can realize the voice recognition and transformation. For this reason, iFlytek Input can be installed on the Android smart phone to recognize and convert the original speech information [4]. 

As a consequence, the handled information will be transmitted to the SCM MSP430F169 through Bluetooth wireless communications. B.Single Chip Microcomputer As the core component of the whole hardware system, the SCM MSP430F169 collects all kinds of input information, refine rough data and control the external equipment. Texas instruments (TI) had introduced the low power consumption microprocessor MSP430 series at the end of the twentieth century. As one member of them, the SCM MSP430F169 has the advantage of strong capacity of handling data, fast operation speed, high on-chip resources integration, low power consumption, stable operation and flexible peripheral interface [5]. The SCM MSP430F169 consists of many function modules: the 16-bit central processor CPU; 16-bit timer/counter B7 with seven kinds of capture Comparator; the timer A; Direct memory access (DMA) controller; 12-bit AD/DA converter; Multiplier; All kinds of memory (flash memory, random access memory, etc..); 6 separate 8-bit parallel ports; Crystals and clock circuit; watchdog circuit and so on. 

According to this structure, encapsulation of MSP430F169 is 64 pin, which can be connected with all kinds of external interface components to realize the interaction of information [6]. Therefore, connecting the Bluetooth wireless transmission module, the SCM MSP430F169 will receive the recognized digital information by means of serial communication. C.Bluetooth Wireless Communication Bluetooth is a kind of wireless transmission technology standards, data can be transmitted among the fixed hardware devices, mobile devices and Local Area Network (LAN) in the short distance by using Bluetooth technology. Moreover, Bluetooth protocol supports RS-232 serial data transmission standards [7].