This application claims the benefit of prior filed Chinese application filed on Oct. 22, 2002 through international application PCT/CN2003/000872 filed on Oct. 20th, 2003 designating the United States of America. The present invention is related to bionic automatic vision and line of sight control system and method, also known as bionic robot eyes, which use cameras as the human eyes, wherein the motions of the cameras are controlled by principles of the nerve systems of human eyes. Therefore, the present invention has similar functions as the human eyes, it can perform object positioning, line of sight tracking, and compensate deviation of line of sight due to the movement of the system, especially because the current invention is capable of assuring simultaneous positioning of both eyes and following the same object, which leads to accurate measuring of the object position and distance, and obtain clear image of the object.
The conventional object tracking methods of automatic surveillance systems mainly use visual feedback control techniques only. When only these methods are used, the speed of tracking the object is very low, so it cannot follow the moving speed of itself or the moving speed of the object. The compensation method for vibration and movement of the camera is merely for minor movement adjustment using image processing, similar to the treatment of preventing the hand shaking when holding a home video camera. The magnitude of the compensation is small. When more than two cameras are used, the position of each camera is fixed in respect to each other. When each camera are controlled independently, multiple cameras cannot simultaneously position and track the same object. When the tracked object needs to be zoomed in, other objects will escape from the viewing field and cannot be tracked.
The object of the present invention is to provide an bionic automatic vision and line of sight control system, wherein the control principle of the nerve system of human oculomotor system was used to obtain the automatic control system and automatic control method to control the movements of the cameras, in order to accurately, quickly and precisely detect the object position and track the object by the line of sight, by reducing the deviation of camera's line of sight caused by the strong and wide range vibration and movement of camera itself, to ensure multiple cameras to detect and track the same object. Furthermore, it is possible to observe and monitor wide range, to watch surrounding objects and change into tracking other object while measuring, tracking and recording the object precisely.
One preferred embodiment of the precise invention is disclosed as the following:
When the telephoto camera focus on an interested object, because of the clear image, the feature point of the object can be found, and the telephoto camera then focus on the feature point (similar to the second saccade human eye movement). When the feature point moves, the image processing program of the telephoto camera will calculate the horizontal and vertical deviation between the feature point and the center of the visual field and the movement speed, the deviation and speed information are used to control the rotation movement of the camera set, to automatically track the feature point (similar to the smooth pursuit human eyeball movement).
When multiple interested objects appear in the visual field of the wide angle camera, each object is numbered according to the appearing sequence or its relative position in the visual field, and then be focused on in turn as stated above. The “interested object” here can be selected according to user's request, such as moving object in the visual field, object with special color, special shape (e.g. face, figure, car, stair, etc.), or it can be selected directly through user interfaces such as keyboard or screen. Similarly, when multiple feature points appear in the visual field of the telephoto camera, based on the relative position of each feature point to the center point of the visual field, the center of the visual field can moved to point at each feature point according to given time period and
In addition, when this oculomotor system-is installed on a moving object (e.g. a car), the binocular system can be placed on a base that can rotate with multiple degree of freedom, similar to a human head. A pair of three degrees of freedom rotation acceleration transducers and a pair of three degrees of freedom translation acceleration transducers are located on each side of the “head” to measure the movement of the head and send signals directly to control forward feeding movement of the “eyeballs”, to enable the system to compensate the sight deviation caused by the movement of the object (similar to vestibulo-ocular reflex).
Multiple microphones can be installed on both sides of the head or other fixed location, to turn head to the sound source.
The embodiment of the control method of the present invention is shown as below:
By using the above mentioned technical method, when the automatic vision and line of sight control system of the present invention are used in surveillance system, clear (precise) images of each person presented can be taken and recorded in turn, and each attendance's movement can be recorded real time, and automatically send out different levels of alarms. The present system can be used not only in fixed location indoor and outdoor surveillance, it can also be used in short distance low altitude on air surveillance, supplemental to a radar. In addition, the present system can be installed on many kinds of moving devices or equipments, such as car, train, airplane, boat, etc, by compensating the deviation of line of sight caused by severe and wide range movement of itself. Appling the control principle of the present invention to various robot's eyes, it will be possible to use household robot. Appling the control principle of the present invention, low cost camera (or fake eyeball) can be used as the eyes of the toys, and it will make the toys appear to be alive.
Two camera sets 1 are installed on the base 11. The actuator control circuit works like this: the digital signal from the central controller is inputted into the D/A converter 9, and the analog signal converted by the D/A converter 9 is inputted into the actuator driving controller 5, and the driving controller 5 drives the actuators 6, while the rotation transducer 7 on the actuators 6 send the rotation angle signal of actuator 6 to the A/D converter (or counter) 10, then sent to the central controller 4.
The image signals of each camera set 1 are sent to the central controller 4 through visual card 3, and the object position deviation and speed related to the line of sight of the camera are obtained through image processing.
The rotation and translation movement of the head (base 1) are detected by the rotation and translation acceleration transducers 8, and sent to the central controller 4 through the A/D converter (or counter) board 10.
The audio signal detected by the microphones 2 installed on both sides of the head (base 11) is sent to the central controller 4 through audio card 12, and the relative position of the sound source to the head is measured, to help the eyeball locate the object's position quickly.
Wherein, Tvm, Tv, Ts are time constants, and ρ, ρr, σ, σr, η, ηr, κx, κxr, κy, κyr, κΦ, κΦr are all positive parameters. {dot over (Φ)}t-l and {dot over (Φ)}t-r are respectively the relative speed between the object and the line of sight of the telephoto cameras of the left and right camera set. Equation (1) is the equation of vergence movement, and Equation (2) is equation of conjugate movement. Each actuator's rotation angle can be obtained through (1)+(2) and (1)−(2). According to equation (1) and (2), the response speed of conjugate movement (proportional to reciprocal of time constant Tvm[1+(ρ−ρr)(η−ηr)]/[1+Tvm(ρ−ρr)(σ−σr)]) is faster than that of vergence movement (proportional to reciprocal of time constant Tvm[1+(ρ+ρr)(η+ηr)]/[1+Tvm(ρ+ρr)(σ+σr)]). This feature ensures that both eyes are able to focus at that the same object simultaneously.
The signals Φw-l and Φw-r of the object obtained from processing the images from the wide angle cameras are used to select best “saccade” control curve. The control curve is used to control actuator to rotate rapidly, to obtain the effect of saccade movement. In addition, the signal from the telephoto camera is cut off when the “saccade reflection” control is used. The generation of saccade eye movement control curve is realized through linear Fourier Series Transformation. Concretely, if assuming that the line of sight moves from current position to the object position within time T, the system control curve consists of m series of sine curve and cosine curve with cycle T, T/2, T/3, . . . T/m.
Wherein, a0, an, bn are obtained by using repetitive learning Inverse Fourier Transformation to process control error by reverse transformation. That is,
Wherein, i indicates the number of learning times. R(t) is the optimal locus of the actuator from transformation of the error measured by wide angle cameras. iθ(t) is the rotation angle of the actuator at the ith learning time. Actuator 61 and actuator 6r use the same method for learning. Each curve can be generated and sustained with 2m+1 coefficients (a0, an, bn, n=1, 2 . . . m) (generally m<10). Since it is possible that each camera set 1 needs hundreds of thousands of saccade eye movement control curve, a great amount of memory capacities can be saved, and the memories can be quickly uploaded. of the feedback circuit of the block diagram can also be removed.
When the automatic vision and line of sight control system are fixed to a big volume indoor space for surveillance, a fixed sky eye, a camera with super wide camera lens (nickname fish-eye lens) or an omnidirectional camera can record the whole moving process of all the moving objects in the surveillance area, and send the interested object to binocular line of sight control system.
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The optimal construction of the automatic vision and line of sight control system is a binocular system (It has two camera sets), the location of which can be determined by specific design, and two or more set can be installed, and each eye can add various sets of cameras with different angles and shooting ranges. In the case of multiple units of binocular systems, the unit that the central controller gives the highest priority is called main unit of eyes. While each binocular system with two camera sets track the same object, different binocular system can track different object respectively (just like each
Same as
Number | Date | Country | Kind |
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PCT/CN03/00872 | Oct 2003 | WO | international |