Research On High-accuracy Blind Naviga-ton Key Issues Based On Haptic And Spa-tial Cognition

Vision is an effective way for people with normal vision to obtain information,but for the blind,achieving the acquisition of environmental information only with other sensory compensation.In real life,blind people cannot be effective means to get most information due to the complexity of the geographical environment.In this case,they would use external tools such as blind rods or guide dogs to reach the destination.However,as the blind demand and the function of the tool itself are limited,and the visually impaired has a higher expectations of navigation tools,how to achieve destination with high accurately position is urgent needs.In this dissertation,achieving the destination is ultimate goal in geographical environment,the realization way is to combine the special characteristics of the blind spatial cognition,loading different vibration tips,and using ultra-wideband wireless positioning technology to achieve the blind in the geographical environment of highprecision positioning to provide a set of behavior consistent with the blind habits of the solution.Cognitive situation is investigated with questionnaires and interviewing by teachers and students of the Blind school in Urumqi,the statistical results of the survey were analyzed from four aspects of environmental overall cognition,direction sense,distance estimation and destination accessibility.On the basis of using the Android smartphone platform and exploring the differential vibration service mode suitable for the blind,the differential path induction is realized by setting the different time of the combination of vibration.Including seven group vibration mode consist of the left-turn vibration tip,right-to-shake tip,reverse walking vibration hint,obstacle,correct walking vibration hint,red light vibration hint and green light vibration hint tip.In order to test results of the blind and discerning the actual vibration,choosing the most appropriate vibration mode to provide a feasible vibration hint scheme for the blind,the above shock combinations need to be tested.After the differential vibration hint method is determined,the carrier is needed.Considering that the visually impaired has a high realistic demand for positioning accuracy and sensitivity of the path induction equipment,this paper adopts ultra-wideband wireless positioning technology to construct the blind navigation experiment platform,sending the blind localization information to the smartphone with wireless,and realizing the specific vibration mode in the experimental environment to induce the blind to arrive at the destination.The system’s hardware environment and software environment are set up,and the system is tested by "differential vibration" and "differential vibration plus phonetic hint".The system takes the actual experience of the blind as the evaluation criterion,and uses the 5 Likert scale to score the walking performance of the blind in the environment.After the system test,the blind scored the system with 10 Likert scale in seven aspects of real-time,usability,wearable,low cost,friendliness,robustness,positioning accuracy,and compared with other blind navigation systems.The results showed that:(1)There were significant differences in the target accessibility and environmental overall cognition of visually impaired by different eyesight levels in visually impaired,which means that the psychological maps of blind people were scattered and failed to form one by one corresponding relationship with the actual environment;On the overall cognition of the environment,the first-level blind and discerning the difference is significant,which means the situation have a large correlation with eyesight,the firstlevel blind is limited to see the surrounding environment,the sense of direction for the visually impaired is generally poor,and the identification of azimuth need training.(2)The poorer eyesight of the blind,the more sensitive to the differential vibration mode;Male blind people are sensitive to the number of vibrations,the female blind is sensitive to the vibration.(3)The "Differential Vibrations" and "differential vibrations plus voice prompts" can lead the blind to the predetermined destination.However,the use of " differential vibrations plus voice prompts" is more obvious than the effect of the method of vibration,and compared with the other blind navigation system,founding that ours system has a slight advantage of the blind path induction.