200927546 九、發明說明： .【發明所屬之技術領域】 本發明涉及一種汽車防撞系統及方法。 【先則技術】 目前’發達之交通及成熟之汽車工業使得交通問題也 隨之凸顯’特別係交通事故頻發造成大量財產損失及人員 傷亡。許多交通事故中係由於司機自身疏忽’造成未能及 ^地對一些行車不安全因素做出處理，從而導致車禍發生。 ❹ 【發明内容】 有鑒於此，有必要提供一種保障行車安全之汽車防撞 系統及方法。 。一種汽車防撞系統，其包括鏡頭、影像感測器、處理 器、報警裝置及迷度檢測裝置。所述汽車防撞系統還包括 個被動式自動對焦系統，該系統包括一個影像處理模塊 及一個鏡頭驅動模塊，所述影像處理模塊與影像感測器電 ❿連接，其能夠對鏡頭處於多個位置時，計算影像感測器所 抓取之影像之影像清晰度資訊’得到鏡頭前方目標物體之 對焦位置’所述鏡頭驅動模塊用於移動鏡頭。所述報警裝 置用於發出報警資訊，所述速度檢測裝置用於獲取本車當 前速度。所述處理器包括：焦距獲取模塊，用於獲取被動 式自動對焦系統得到之鏡頭前方目標物體之對焦位置，根 據焦距及像距計算出鏡頭前方目標物體與本車之間之當前 距離；速度獲取模塊，用於獲取速度檢測裝置得到之本車 當前迷度；參數設置模塊’用於設置本車速度與與存儲於 200927546 • 參數設置模塊内之安全距離對應關係；判斷模塊，用於將 、當前距離與當前速度對應之安全距離進行比較；報警模 ' 塊’用於根據比較結果控制報警骏置。 一種汽車防撞方法，包括以下步驟：對鏡頭前方目標 物體進行被動式自動對焦；獲取對焦後鏡頭之位置，根據 焦距及像距计算出本車與鏡頭前方目標物體之間之距離； 獲取本車當前之移動速度；獲取本車當前移動速度對應之 安全距離；判斷本車與鏡頭前方目標物體之間之距離是否 © 於女全距離之内’本車與鏡頭前方目標物體之間之距離小 於安全距離時進行報警。 由於該汽車防撞系統採用自動對焦系統，判斷出車輛 間之距離，當發現車距小於安全距離時，發出警報對司機 進行提醒’從而可以使司機預先發現危險發生，及時做出 處理，防止車禍發生。 【實施方式】 請參閱圖1，為本發明汽車防撞系統1〇〇。本實施方式 © 中，所述汽車防撞系統100包括影像感測器10、被動式自 動對焦系統20、處理器30、報警裝置40、速度檢測裝置 50及鏡頭90。 所述被動式自動對焦系統20包括一個影像處理模塊 21及一個鏡頭驅動模塊22，所述影像處理模塊21與影像 感測器10電連接，其能夠對鏡頭9〇處於多個位置時，計 算影像感測器1〇所獲取之影像之影像清晰度資訊，得到鏡 頭90對鏡頭前方目標物體（未標號)之對焦位置。所述影像 200927546 處理模塊21對鏡頭90處於多個位置時影像感測器10所輸 出之電訊號進行分析運算，得到鏡頭前方目標物體最清晰 ' 之影像時鏡頭90對焦位置，由鏡頭90焦距及此時像距計 算出本車與鏡頭前方目標物體之距離。所述清晰度資訊為 被攝物影像之對比度、灰度、亮度或邊緣強度資訊。本實 施方式中，採用對比度、灰度、亮度之資訊作為評價清晰 度之資訊。 所述鏡頭驅動模塊22用於對焦時移動鏡頭90。獲得 ❹ 車體之實際對焦位置前，該鏡頭驅動模塊22可多次移動鏡 頭90，從而可以使影像感測器10獲得鏡頭90處於多個位 置時鏡頭前方目標物體之影像。獲得鏡頭前方目標物體之 實際對焦位置後，該鏡頭驅動模塊22可移動鏡頭90到對 焦位置以完成對焦。 報警裝置40，用於發出報警資訊。該報警資訊可以係 視覺或聲音資訊。所述報警裝置40可採用液晶顯示器或發 光二極體，也可採用揚聲器或蜂鳴器。本實施方式中，採 © 用液晶顯示器顯示警告資訊。 所述速度檢測裝置50，用於獲取本車當前速度，並將 其轉化為電訊號。本實施方式中，所述速度檢測裝置50獲 取車之車速，可獲取汽車之機械測速計或電子測速計之速 度值，將速度值轉為數位訊號。 本實施方式中，所述處理器30根據本車當前速度及測 出兩車當前之車距與安全距離進行比較，判斷是否需要報 警。若兩車之車距小於安全距離，則報警；否則，不進行 200927546 > 報警。 請參閱圖2 ’所述處理器30包括：焦距獲取模塊31、 速度獲取模塊32、參數設置模塊33、判斷模塊34及報警 模塊35。 所述焦距獲取模塊31，用於獲取被動式自動對焦系統 20得到之鏡頭之對焦位置’根據焦距及像距計算出當前距 離。本實施方式中，所述當前距離為根據被動式自動對焦 系統20得到鏡頭前方目標物體最清晰之影像時鏡頭90之 ❹ 對焦位置及焦距，通過計算得出本車與目標物體之距離。 速度獲取模塊32，用於獲取速度檢測裝置50得到之 本車速度。本實施方式中’速度獲取模塊32獲取所述速度 檢測裝置50獲取車之車速轉化後之數位訊號。 參數設置模塊33,用於設置本車之速度與存儲於參數 設置模塊内之安全距離對應關係。由於不同速度所需之安 全距離不同。所以通過設置該參數設置模塊33 ’可以預先 對應設置不同速度所需之安全距離不同°本實施方式中’ ® 按照車輛之大小及不同速度對應設置多個安全距離。例 如，小型車之安全距離設置為車輛速率之每小時公里數值 除以二，單位為米。 判斷模塊34，用於將當前距離與對安全距離進行比 較。本實施方式中，該判斷模塊34根據當前速度獲取之當 前車距與該速度下對應之安全距離進行比較。例如，小汽 車當前速度為50公里每小時，當前距離為15米，該判斷 模塊34將50公里每小時之車速對應之安全車距25来與當 200927546 t 前距離15米進行比較。 報警模塊35，用於根據比較結果控制報警裝置4〇。當 車距小於安全距離時，該報警模塊35給報警裝置40發送 Λ號，報警裝置4〇進行報警。否則，不進行報警。例如， 當前距離15米小於安全車距25 #，本實施方式中，該報 警模塊35給液晶顯示|!發送報警訊號，液晶顯示器顯示文 字資訊進行報警。 請參閱圖3，本發明還提供一種防撞方法。 步驟S11 :對車體進行被動式自動對焦。 ，驟S15 :獲取自動對焦後鏡頭之位置，根據焦距及 像距计算出本車與鏡頭前方目標物體之間之距離。本實施 方式胃中’所述目標物體之距離為根據被動式自動對焦系統 20得到鏡頭前方目標物體最清晰之影像時鏡頭9〇之對焦 位置及焦距，通過計算得出物體之距離。 步驟S17 :獲取本車當前移動速度。本實施方式中， ❿所述速度檢測裝置50獲取車之車速，可獲取汽車之機械測 ' 速計或電子測速計之速度值，將速度值轉為數位訊號。 步驟S21 :獲取本車當前移動速度對應之安全距離6 本實施方式中，判斷模塊34根據當前速度獲取於該速度下 對應之安全距離。 步驟S23 :判斷本車與目標物體之間之距離是否於安 全距離之内。本實施方式中，判斷模塊34根據當前速度獲 取之古前車距與該速度下對應之安全距離進行比較。 步驟S27:當本車與鏡頭前方目標物體之間距離小於 11 200927546 , 安全距離時進行報警。本實施方式中，車距小於安全距離 時，所述報警模塊35給報警裝置4〇發送訊號，報警裝置 、 40進行報警。 步驟S27中’若本車與鏡頭前方目標物體之間之距離 大於安全距離時，則不報警。 由於該汽車防撞系統採用自動對焦系統，判斷出車輛 之間距離，當發現車距小於安全距離時，發出警報對司機 進行提醒，從而可以使司機預先發現危險之發生，及時做 ❹ 出處理，防止車禍發生。 综上所述，本發明符合發明專利要件，爰依法提出專 利申請。惟，以上所述者僅為本發明之較佳實施方式，本 發明之範圍並不以上述實施方式為限，舉凡熟悉本案技藝 之人士援依本發明之精神所作之等效修飾或變化，皆應涵 蓋於以下申請專利範圍内。 【圖式簡單說明】 圖1為本發明汽車防撞系統之硬體架構圖。 ® 圖2為本發明處理器之功能模塊圖。 圖3為本發明防撞方法之流程圖。 【主要元件符號說明】 汽車防撞系統 100 影像感測器 10 被動式自動對焦系統 20 影像處理模塊 21 鏡頭驅動模塊 22 處理器 30 焦距獲取模塊 31 速度獲取模塊 32 12 200927546 參數設置模塊 33 判斷模塊 34 報警模塊 35 報警裝置 40 速度檢測裝置 50 鏡頭 90 ❹ 13200927546 IX. Description of the invention: [Technical field to which the invention pertains] The present invention relates to an automobile collision avoidance system and method. [First-class technology] At present, the developed transportation and the mature automobile industry have made traffic problems prominent. The special traffic accidents caused a lot of property damage and casualties. In many traffic accidents, the driver’s own negligence caused the failure to deal with some unsafe factors, which led to a car accident. ❹ [Summary of the Invention] In view of this, it is necessary to provide a car collision avoidance system and method for ensuring driving safety. . An automobile collision avoidance system includes a lens, an image sensor, a processor, an alarm device, and a temperature detecting device. The automobile collision avoidance system further includes a passive autofocus system, the system includes an image processing module and a lens driving module, and the image processing module is electrically connected to the image sensor, and is capable of positioning the lens in multiple positions. Calculating the image sharpness information of the image captured by the image sensor 'obtaining the focus position of the target object in front of the lens'. The lens driving module is used to move the lens. The alarm device is configured to issue an alarm message, and the speed detecting device is configured to acquire the current speed of the vehicle. The processor includes: a focal length acquiring module, configured to acquire a focus position of a target object in front of the lens obtained by the passive autofocus system, and calculate a current distance between the target object in front of the lens and the vehicle according to the focal length and the image distance; and the speed acquiring module For obtaining the current obscurity of the vehicle obtained by the speed detecting device; the parameter setting module 'for setting the relationship between the speed of the vehicle and the safety distance stored in the parameter setting module of 200927546; the determining module for the current distance The safety distance corresponding to the current speed is compared; the alarm mode 'block' is used to control the alarm according to the comparison result. A car collision avoidance method includes the following steps: passively autofocusing a target object in front of the lens; obtaining a position of the lens after focusing, calculating a distance between the vehicle and a target object in front of the lens according to the focal length and the image distance; The moving speed; obtain the safety distance corresponding to the current moving speed of the vehicle; determine whether the distance between the vehicle and the target object in front of the lens is within the female full distance. The distance between the vehicle and the target object in front of the lens is less than the safety distance. When an alarm occurs. Since the automobile anti-collision system adopts an auto-focus system to determine the distance between the vehicles, when the vehicle distance is found to be less than the safety distance, an alarm is issued to alert the driver, so that the driver can detect the danger in advance and timely deal with the vehicle accident. occur. [Embodiment] Please refer to FIG. 1 , which is a car collision avoidance system of the present invention. In the present embodiment, the automobile collision avoidance system 100 includes an image sensor 10, a passive autofocus system 20, a processor 30, an alarm device 40, a speed detecting device 50, and a lens 90. The passive auto-focus system 20 includes an image processing module 21 and a lens driving module 22, and the image processing module 21 is electrically connected to the image sensor 10, which can calculate the image sense when the lens 9 is in multiple positions. The image sharpness information of the image acquired by the detector 1 is obtained by the focus position of the lens 90 on the target object (not labeled) in front of the lens. The image 200927546 processing module 21 analyzes and calculates the electrical signal output by the image sensor 10 when the lens 90 is at a plurality of positions, and obtains the focus position of the lens 90 when the image of the target object in front of the lens is the clearest, and the focal length of the lens 90 and At this time, the distance between the vehicle and the target object in front of the lens is calculated. The sharpness information is contrast, grayscale, brightness or edge intensity information of the subject image. In this embodiment, information on contrast, gradation, and brightness is used as information for evaluating the degree of clarity. The lens driving module 22 is used to move the lens 90 during focusing. Before the actual focus position of the vehicle body is obtained, the lens driving module 22 can move the lens 90 a plurality of times, so that the image sensor 10 can obtain an image of the target object in front of the lens when the lens 90 is in multiple positions. After obtaining the actual focus position of the target object in front of the lens, the lens drive module 22 can move the lens 90 to the focus position to complete the focus. The alarm device 40 is configured to send an alarm message. This alarm information can be visual or sound information. The alarm device 40 can be a liquid crystal display or a light emitting diode, and a speaker or a buzzer can also be used. In the present embodiment, the warning information is displayed on the liquid crystal display. The speed detecting device 50 is configured to acquire the current speed of the vehicle and convert it into an electrical signal. In the present embodiment, the speed detecting device 50 obtains the vehicle speed of the vehicle, and can obtain the speed value of the mechanical speedometer or the electronic speedometer of the automobile, and converts the speed value into a digital signal. In this embodiment, the processor 30 compares the current vehicle speed and the current vehicle distance and the safety distance of the two vehicles to determine whether an alarm is required. If the distance between the two cars is less than the safety distance, the alarm will be given; otherwise, the 200927546 > alarm will not be performed. Referring to FIG. 2, the processor 30 includes a focus acquisition module 31, a speed acquisition module 32, a parameter setting module 33, a determination module 34, and an alarm module 35. The focal length acquisition module 31 is configured to acquire the focus position of the lens obtained by the passive autofocus system 20 to calculate the current distance according to the focal length and the image distance. In the embodiment, the current distance is the focus position and the focal length of the lens 90 when the passive autofocus system 20 obtains the clearest image of the target object in front of the lens, and the distance between the vehicle and the target object is calculated by calculation. The speed acquisition module 32 is configured to acquire the vehicle speed obtained by the speed detecting device 50. In the present embodiment, the speed acquisition module 32 acquires the digital signal after the speed detecting device 50 acquires the vehicle speed conversion. The parameter setting module 33 is configured to set a correspondence relationship between the speed of the vehicle and the safety distance stored in the parameter setting module. The safety distances required for different speeds are different. Therefore, by setting the parameter setting module 33', the safety distances required for setting different speeds in advance can be different. In the present embodiment, the plurality of safety distances are correspondingly set according to the size of the vehicle and the different speeds. For example, the safety distance of a small car is set to the hourly kilometer value of the vehicle speed divided by two, in meters. The determining module 34 is configured to compare the current distance with the safe distance. In this embodiment, the determining module 34 compares the current distance acquired according to the current speed with the corresponding safe distance at the speed. For example, the current speed of a small car is 50 km/h and the current distance is 15 m. The judgment module 34 compares the safety distance of 25 km/h to the front distance of 15 m when 200927546 t. The alarm module 35 is configured to control the alarm device 4 according to the comparison result. When the vehicle distance is less than the safety distance, the alarm module 35 sends an nickname to the alarm device 40, and the alarm device 4 〇 performs an alarm. Otherwise, no alarm will be given. For example, the current distance of 15 meters is less than the safety distance 25 #. In the present embodiment, the alarm module 35 sends an alarm signal to the liquid crystal display |!, and the liquid crystal display displays the text information for alarm. Referring to FIG. 3, the present invention also provides an anti-collision method. Step S11: Passive autofocusing on the vehicle body. Step S15: Obtain the position of the lens after autofocus, and calculate the distance between the vehicle and the target object in front of the lens according to the focal length and the image distance. In the present embodiment, the distance of the target object in the stomach is the focus position and the focal length of the lens 9 when the passive AF system 20 obtains the clearest image of the target object in front of the lens, and the distance of the object is calculated. Step S17: Acquire the current moving speed of the vehicle. In the present embodiment, the speed detecting device 50 obtains the vehicle speed, and can obtain the speed value of the mechanical speedometer or the electronic speedometer of the automobile, and convert the speed value into a digital signal. Step S21: Obtaining the safety distance corresponding to the current moving speed of the vehicle. In the embodiment, the determining module 34 acquires the safety distance corresponding to the speed according to the current speed. Step S23: It is judged whether the distance between the vehicle and the target object is within a safe distance. In this embodiment, the judging module 34 compares the pre-euro distance obtained from the current speed with the corresponding safety distance at the speed. Step S27: When the distance between the vehicle and the target object in front of the lens is less than 11 200927546, the safety distance is alarmed. In the present embodiment, when the vehicle distance is less than the safety distance, the alarm module 35 sends a signal to the alarm device 4, and the alarm device 40 performs an alarm. In step S27, if the distance between the vehicle and the target object in front of the lens is greater than the safety distance, no alarm is given. Since the automobile anti-collision system adopts an auto-focus system to determine the distance between the vehicles, when the vehicle distance is found to be less than the safety distance, an alarm is issued to alert the driver, so that the driver can detect the occurrence of the danger in advance and perform the processing in time. Prevent car accidents. In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. However, the above description is only the preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiments, and equivalent modifications or variations made by those skilled in the art in light of the spirit of the present invention are It should be covered by the following patent application. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a hardware structural diagram of a car collision avoidance system of the present invention. ® Figure 2 is a functional block diagram of the processor of the present invention. 3 is a flow chart of a collision avoidance method of the present invention. [Main component symbol description] Car collision avoidance system 100 Image sensor 10 Passive AF system 20 Image processing module 21 Lens drive module 22 Processor 30 Focus acquisition module 31 Speed acquisition module 32 12 200927546 Parameter setting module 33 Judgment module 34 Alarm Module 35 Alarm device 40 Speed detection device 50 Lens 90 ❹ 13