發(fā)布時(shí)間：2018-12-12 11:46

【摘要】：隨著定位技術(shù)的提高,GPS(Global Position System)定位系統(tǒng)已經(jīng)可以實(shí)現(xiàn)亞米級(jí)精度的定位。但高精度GPS成本很高,且無(wú)法用于室內(nèi)定位。目前已有的定位方式大多以人為定位主體,強(qiáng)調(diào)在客戶(hù)已有硬件的基礎(chǔ)上進(jìn)行定位,存在定位精度低、成本高等問(wèn)題。而精度較高的超聲波定位系統(tǒng)又存在定位目標(biāo)容量有限和數(shù)據(jù)更新速率低的問(wèn)題,無(wú)法用于較快速的移動(dòng)控制或多目標(biāo)編隊(duì)控制場(chǎng)景。為了讓多個(gè)目標(biāo)在室內(nèi)環(huán)境下獲得各自準(zhǔn)確的位置信息,本文在超聲波測(cè)距的基礎(chǔ)上實(shí)現(xiàn)了室內(nèi)精確定位。在室內(nèi)固定位置安裝3個(gè)或以上的超聲波發(fā)射節(jié)點(diǎn)向外發(fā)送超聲波信號(hào)。將定位節(jié)點(diǎn)放入能接收到超聲波信號(hào)的區(qū)域內(nèi),其自動(dòng)加入定位系統(tǒng)的無(wú)線(xiàn)網(wǎng)絡(luò),并完成時(shí)間同步以后,即能連續(xù)獲取位置信息。本系統(tǒng)充分結(jié)合超聲波收發(fā)器的硬件特性,對(duì)相應(yīng)算法以及硬件電路進(jìn)行改進(jìn)與優(yōu)化,完成電路板設(shè)計(jì)與調(diào)試,并最終完成超聲波實(shí)時(shí)定位系統(tǒng)實(shí)物。本文中,基于無(wú)線(xiàn)網(wǎng)絡(luò)的精確時(shí)間同步以及避免多超聲波發(fā)射節(jié)點(diǎn)相互干擾是研究的重點(diǎn)。在精確時(shí)間同步部分,本文采用TI的CC1101無(wú)線(xiàn)數(shù)字通信芯片,工作在ISM(Industrial Scientific Medical Band)規(guī)定的433 HMz頻段進(jìn)行無(wú)線(xiàn)通信。本文通過(guò)自定義通信數(shù)據(jù)結(jié)構(gòu)與網(wǎng)絡(luò)拓?fù)浣Y(jié)構(gòu),在滿(mǎn)足相互之間通信要求的情況下最大程度降低通信延遲。經(jīng)實(shí)測(cè),時(shí)間同步誤差小于100 us。在防止超聲波發(fā)射節(jié)點(diǎn)之間相互干擾方面,定位系統(tǒng)的所有超聲波發(fā)射器按CDMA(Code Division Multiple Access)的要求把擴(kuò)頻后的超聲波信號(hào)向地面廣播。接收機(jī)在對(duì)信號(hào)進(jìn)行解擴(kuò)后,有效的區(qū)分開(kāi)不同的超聲波發(fā)射節(jié)點(diǎn)的同時(shí)還能獲取準(zhǔn)確超聲波到達(dá)時(shí)間,避免環(huán)境因素造成的多徑效應(yīng)以及干擾帶來(lái)的影響,從而有效提高測(cè)距系統(tǒng)的抗干擾性能。同時(shí)配合卡爾曼濾波器對(duì)獲得的位置數(shù)據(jù)進(jìn)行處理,從而獲得更高的定位精度。經(jīng)過(guò)測(cè)試,定位誤差小于0.11 m。
[Abstract]:With the improvement of positioning technology, GPS (Global Position System) positioning system has been able to achieve sub-meter precision positioning. However, high precision GPS is very expensive and can not be used for indoor positioning. At present, most of the existing positioning methods are based on artificial positioning, which emphasizes positioning on the basis of existing hardware, which has the problems of low positioning accuracy and high cost. However, the ultrasonic positioning system with high precision has the problems of limited target capacity and low data update rate, which can not be used in fast moving control or multi-target formation control scenarios. In order to obtain accurate position information of multiple targets in indoor environment, this paper realizes indoor accurate location on the basis of ultrasonic ranging. Three or more ultrasonic transmitting nodes are installed in a fixed position in the room to send out ultrasonic signals. The location node is placed in the area where the ultrasonic signal can be received, and it automatically joins the wireless network of the positioning system, and after the time synchronization is completed, the position information can be obtained continuously. This system combines the hardware characteristic of ultrasonic transceiver, improves and optimizes the corresponding algorithm and hardware circuit, completes the circuit board design and debugging, and finally completes the ultrasonic real-time positioning system. In this paper, precise time synchronization based on wireless network and avoiding interference between multiple ultrasonic transmitting nodes are the key points of the research. In the part of precise time synchronization, the CC1101 wireless digital communication chip of TI is used to work in the 433 HMz band specified by ISM (Industrial Scientific Medical Band). In this paper, the communication delay is minimized by customizing the communication data structure and the network topology structure under the condition of satisfying the requirements of communication between each other. Measured results show that the time synchronization error is less than 100 us.. In order to prevent the interference between the ultrasonic transmitting nodes, all the ultrasonic transmitters of the positioning system broadcast the spread spectrum ultrasonic signals to the ground according to the requirements of CDMA (Code Division Multiple Access). After despreading the signal, the receiver can effectively distinguish the different ultrasonic transmitting nodes and obtain the accurate ultrasonic arrival time at the same time, to avoid the multi-path effect caused by the environmental factors and the influence of the interference. Therefore, the anti-jamming performance of ranging system is improved effectively. At the same time, the position data is processed with Kalman filter to obtain higher positioning accuracy. After testing, the positioning error is less than 0.11 m.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類(lèi)號(hào)】：TB559

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本文編號(hào)：2374496