| In recent years,with the rapid development of virtual reality technology,utilize it to replace the actual needs of large flight simulators is very urgent.Virtual reality flight simulator has such advantages as small volume,low cost,easy to move and expand.It changes the disadvantages of large scale flight simulator,such as high cost,complex physical equipment connection,large volume and so on.The engineering technology center of flight simulation and training in Nanjing University of Aeronautics & Astronautics is the research institutions which is early successful one in china in using virtual reality Flight Simulator,and the "light flight simulator prototype system-canoe one" is developed successfully,bring forward the concept of enhance semi virtual reality cockpit.The cockpit view is the same as the computer generated image,extravehicular transformation scene is calculated by the computer using the three-dimensional modeling software which real time inputs immersive helmet.However,the system has a certain cable constraint for the operator's visual helmet positioning,such as electromagnetic tracker and other physical devices.Electromagnetic interference also affects other devices in the cabin,affecting the immersion and use effect of people.Therefore,this paper mainly studies the "visual interaction scheme of human center",use color markers and infrared identification of visual tracking,and the three-dimensional coordinates can be obtained.The visual positioning interaction scheme is presented in the environment of normal light and low illumination.New kind of flight simulator visual tracking system is realized based on computer vision technology.The main contents of this paper are as follows:1.A technology scheme of enhanced semi virtual reality flight cabin based on visual tracking and positioning is constructed.Physical equipment of traditional virtual reality flight simulator are too much,such as the electromagnetic trackers which are in the positioning of the head and hands and data glove device.At the same time,experience person can not enjoy the visual,tactile and force feedback information in real environment due to the limitation of physical equipment.In view of the above situation,head tracking and positioning system has been developed based on visual interaction,and a technical scheme of enhanced semi virtual reality cockpit has been constructed by using computer vision.It can significantly reduce the cost of software and hardware,and it can be widely promoted.2.According to the characteristics of physical medium in virtual reality cockpit,color markers are used as tracking points,and the 3D space coordinate can be obtained under multi-camera stereoscopic calibration.We propose a kind of fast CSK tracking algorithms which fuses low dimensional theme color space.The real-time color labeling tracking algorithm in the cockpit is studied,and a fast tracking scheme is proposed which fuses the low dimensional theme color space.According to the significant influence of illumination on the color of markers,we try to get constant rules of color markers in cockpit and obtain stable color markers by using lots of experiments under the condition of multi-illumination and multi-intensity.The Mean-shift and particle filter tracking algorithm based on color feature are studied,and a series of tests are set to analyze the advantages and disadvantages of the two algorithms.First,the original color domain is mapped to image feature space,then by adopting the idea of the nearest neighbor,choose the most similar theme colors instead of the original observation color.The algorithm has high efficiency characteristic in the selection of color feature.Experimental results indicate that the proposed method is robust and has good performances under the color controllable feature background without reducing the dimension.3.In view of the stability of environmental light noise interfering with target tracking,the local dynamic sensing and ignoring non restricted area compensation are proposed,and the spatial location is realized with the 3D registration method of the orthogonal camera head position.The method of color target tracking and orthogonal camera 3D registration on head position with the ability of environment perception is presented.Firstly,a dynamic local illumination model was set up to detect the threshold value of ambient light.A local-global combined ambient illumination method was proposed based on prior knowledge and light source information.The tests under artificial light interference simulation environment show that the proposed method is characterized by good robustness and accuracy.The failure problem of user interaction experience which is generated without illumination compensation is solved.According to the arrangement characteristics of the head marks and the camera layout of the cockpit,the multi-point planar coordinate orthogonal camera positioning scheme proposed by the research group is adopted.Experiments show that compared with the traditional electromagnetic tracker,the orthogonal positioning system far exceeds the specified index in the aspects of positioning accuracy,speed and position error,and the error is under 1 mm,which can meet the requirement of enhancing the tracking in the semi-virtual reality cockpit Positioning technical requirements.4.Aiming at the problem of pilot head moving scope in different cockpit environments,an orthogonal positioning scheme for redundant cameras in the full camera field of vision is proposed.The motion range of the pilot's head is studied.A redundant camera orthogonal positioning scheme is proposed in the full camera field of vision,head movements are different,in order to make the full range of motion into the array camera field of view,to solve the initial coordinates change problem of head point because of the driver's posture and different sizes in a variety of flight action,the redundant camera orthogonal positioning system with cockpit range constraints is constructed,and a set of scientific and quantitative experimental scheme for the range of head motion is constructed.The model is established by the principle of human engineering and the series solution at the top of the head.The actual head movement range is obtained under the Boeing 737 cockpit environment.And a kind of redundant orthogonal camera positioning scheme is designed,the characters of the reliability and integrity are improved.5.Because of the color-based scheme can not fully meet the positioning requirements under full immersion and enhanced semi-virtual reality cockpit light interference environment,a kind of infrared target tracking scheme is designed under the low illumination environment,weighted infrared light and visible light fusion tracking method which the multi-feature can be extracted is proposed.LED light source has the characteristics of not being disturbed by external light sources,but at the same time it is easy to fall into three-point coplanar point light source.The design of the cross infrared light source plus the auxiliary infrared marker tracking scheme is given.The stable identification of different identity sequences can be realized through analyzing he geometric distribution of infrared LED light source,and the most typical imaging flare can be found combined with light source direction and circuit control.Several centroid extraction algorithms are studied,and the ideal center coordinates of the target are obtained.The fast tracking can be achieved combined with he moving target matching and the nearest neighbor algorithm.The experimental results show that the proposed algorithm enhances the reliability of tracking.This subject is use of computer vision scheme,the development of a complete enhanced semi virtual reality Flight cockpit system,and the system was actually tested.From the subjective experience of the operator,the experience effect of immersion and unrestraint can be achieved.Objectively speaking,it can meet the requirements of time efficiency and robustness.The light flight simulator based on computer vision not only has the advantages of flexible operation,low cost and strong immersion,but also can be extended to other industries. |
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