WO1992021992A1

WO1992021992A1 - Apparatus for detecting and tracking an object

Info

Publication number: WO1992021992A1
Application number: PCT/AU1992/000257
Authority: WO
Inventors: Frank Joseph Prineppi
Original assignee: Frank Joseph Prineppi
Priority date: 1991-06-07
Filing date: 1992-06-04
Publication date: 1992-12-10
Also published as: AU1923092A; GB9112260D0

Abstract

Apparatus for detecting an object within a certain spacial area and for tracking it as the object moves. This is achieved by emitting a signal such as electro-magnetic radiation or ultrasound and by detecting the amount reflected back at two different points. By comparing the amount detected at each point it is possible to ascertain the direction of an object, point the detector at it and follow it if it moves. This can be used in the eyes of a doll, or in a toy weapons system, following someone around a room.

Description

APPARATUS FOR DETECTING AND TRACKING AN OBJECT

This invention relates to apparatus for detecting and tracking an object within a spatial area such as a room and utilizing for that purpose beams of radiation generally undetectable to the human eye.

In this patent specification the term "radiation" is not intended to be limited to particular frequencies of electro magnetic radiation but may include all kinds of radiation considered suitable for effecting detection and tracking movement such as, in particular, ultrasound.

Various kinds of means are known by which the presence and movement of objects can be detected and tracked but most if not all of these are generally quite complicated and/or cumbersome and are not readily adaptable to small scale apparatus wherein the ability to detect and track moving objects would be desirable, such as in the case of the eyes of a toy doll. It would be highly desirable to provide a toy doll having the ability to move its eyes in response to movement within a spatial area in front of the doll's head, and having detected such movement, to track or follow the object until it is either out of range or has moved outside the spatial area covered by the doll's eyes. Heretofore no means have been known which would be capable of simply and relatively cheaply accomplishing such a task and it is an object of the present invention to provide in particular apparatus for detecting and tracking an object within a spatial area which would be suitable for enabling doll's eyes and/or a doll's head to move in response to movement of an object such as a person and follow such movement in a tracking manner. However, it will be understood to the reader that the principles by which such may be achieved are not limited to the particular application of such to toy dolls and the like but can have broader applications such as in the field of toys generally where, for example, it may be desired to provide tracking movement of toy weapons such as guns and the like when movement is detected within a given spatial area. According to the invention there is provided apparatus for detecting and tracking an object within a spatial area, the apparatus comprising radiation transmission means adapted to project radiation over the spatial area, at least two matching radiation detector means, each being adapted to detect incoming radiation reflected from an object in the spatial area and to produce therefrom electrical signals proportional in strength to the amount of reflected radiation so detected, electrically driven actuator means adapted to move part or all of each detector means to directions within the spatial area over which tracking movement thereof is desired, and control means for comparing the relative strengths of the electrical signals generated by each detector means and producing from said comparison electrical drive signals for driving the actuator means to, in turn, generally continuously orientate each detector or movable part thereof to a position relative to the object so detected at which position the relative strengths of the resultant electrical signals generated by all detector means are generally equal.

Conveniently the radiation transmission means is one or more infrared emitters, such as infrared light emitting diodes (LED's) capable of emitting one or more beans, or a sweep of one or more beams, over the required spatial area covered by the apparatus and being of sufficient power to ensure that radiation reflected from objects within the spatial area is sufficiently strong so as to be detectable by the at least two matching radiation detector means.

Each matching radiation detector means must obviously be capable of detecting the same kind of radiation emitted by the radiation transmitting means such that in the case of the latter being an infrared emitter then each radiation detector means must include an infrared receiver responsive of generally the same wavelength. Similarly, in the event that the radiation transmitted were to be ultrasound then each radiation detection means must include an ultrasound detector for the same general frequency.

In the event that the apparatus were to be used as part of a toy doll then preferably there are two detector means, each being positioned in a respective eye of the doll and each being capable of receiving reflected radiation from the radiation transmission means and producing therefrom the required electrical signals proportional in strength to the amount of reflected radiation so detected. Since it is a requirement of the invention that at least part of each radiation detector means is moveable it will be apparent that if the detection means comprised or included dolls eyes then the eyes themselves must be capable of movement either up or down or, preferably, sideways to the left and right. In such a configuration the electrically driven actuator means can conveniently be adapted to move both of the eyes simultaneously left or right, or up or down as the case may be, in response to the drive signals being received from the control means. Conveniently, if the radiation detector means comprise or include moveable doll's eyes the radiation transmission means may comprise radiation emitters, such as infrared LED's, placed centrally within the iris of each such eye and insulated so as to prevent backwards or sidewards emission of infrared radiation directly onto the detector means and arranged instead, to project a beam of radiation generally forward of the eyes covering a sufficiently wide angle of view such that an object e.g. in human form may be detected over a sufficiently wide area, typically within the confines of a room or the like. In such an arrangement radiation reflected from an object within the spatial area covered by the radiation transmission means must be capable of being received by the detector means and this can be easily and preferably accomplished by including a conventional lens within each eye surrounding each radiation emitter and being capable of focusing reflected radiation onto each respective detector means. In such an arrangement, preferably, the detector means, lens and emitter are all encapsulated within a single housing for each eye and both housings are connected to each other and the actuator means so that they can each move simultaneously in the same direction when actuated by the actuator means. Conveniently, each such housing includes an internal surface whcih is reflective of incoming radiation so as to maximize the strength of reflected radiation received through each eye and detected by the detector means. Such reflective surfaces could include a silvered surface, and particularly a blue-tinted silvered surface such that to an outward observer the eyes look blue rather than simply being transparent or indefinite as to colour. Other colour tints could also be used.

The control means for comparing the relative strengths of the electrical signals generated by each detector means may conveniently comprise an analogue to digital converter, or a conventional analogue to digital microprocessor could be used instead, each being capable of producing a drive signal for moving the actuator means one way or the other, typically left or right or up or down. In the event that no signal is emitted it will be appreciated that the actuator means is at rest and hence movement of part or all of each detector means has stopped.

There may be a pre-amplifier for each detector means in order to amplify the signal generated thereby, comparator means to compare the respective strengths of each resultant signal, preferably with a preset reference signal corresponding to a mimimum level of reflection from an object within the spatial area, and a means for determining whether or not to produce a drive signal for the actuator means and, if so, whether or not such signal should cause the actuator means to move the detector means one way or another such as left or right or up or down. Advantageously, the control means also includes a clock function whereby real time signals received from the detector means are compared with previous signals to determine if there has been any change thereof and, in the event that there has not, which event is indicative of non-movement of an object detected within the spatial area or no detection of any object, to produce drive signals whereby the detector means are driven by the actuator means to point to different parts of the spatial area covered by the apparatus in a scanning mode. In this manner it will be apparent that in the event that the apparatus is incorporated within a doll the clock function of the controlling mechanism can be arranged such that when the doll is switched on, the doll's eyes can be arranged to sweep, for example, from left to right and back continuously until an object with a sufficiently strong reflected signal is detected and for the eyes to stop and the control means to then carry out an evaluative measurement to see if the object is moving and in the event that it is not within a predetermined period of, for example, three seconds, emit a drive signal to the actuator so that the eyes then continue to track over the spatial area right and left and so on until an object is again detected. Because the clock function carries out a continuous revision of the signals being received by the detector means the eyes will continuously be "locked" on the object if it is moving whilst in the spatial area by providing that the actuator means continuously moves the eyes to a position wherein the signals generated by the detector means are generally equal, i.e. to a position wherein the object being detected is orthogonal to the plane of the eyes.

It will be appreciated that the extent of movement either up or down or left or right, of a human eye is necessarily limited and it is a further object of the present invention to provide a mechanism whereby during tracking movement the head of the doll, or some other analogous part if the apparatus if not included in a doll, is adapted to move, preferably by being rotated left or right, as the case may be, when the limit of travel has been reached for each eye so that, for example, if the eyes are tracking from right to left then when the limit of the leftward travel is reached, the head would also continue to rotate leftward until a chosen limit, or even no limit at all, has been reached. In this manner, the realistic effect which may be obtained by use of the invention can be enhanced. For effecting movement of the head once the limit of eye movement is reached, there is preferably provided a linkage between the body of the doll and the head which is also connected to the actuator means, which, in turn, is connected to each eye. The linkage may be connected to the body of the doll by means of a motor within the body of the doll which may conveniently comprise part of the actuator means according to the invention. The drive shaft from the motor may be connected to a main shaft lever arranged such that the eyes are permitted to move leftwards or rightwards within a certain range of movement and, thereafter, a stop mechanism on the drive shaft may prevent the eyes from moving further and may instead transfer the rotational forces to the head of the doll to thereby permit the head to move with the eyes being stationary within the head relative to it. The invention will now be described, by way of example only, with reference to the accompanying drawings in which:-

Figure 1 is a schematic block diagram showing an arrangement suitable for driving a pair of detectors, which may be in the form of dolls eyes, in accordance with an aspect of the invention,

Figure 2 is a schematic top view of a pair of eyes incorporating radiation transmission and detector means and suitable for incorporation within the head of a doll,

Figure 3 is a side view of one of the eyes of Figure 2,

Figure 4 schematically shows the eyes scanning over a spatial area, Figure 5 shows a position in which the eys have

"locked" onto an object within the spatial area depicted in Figure 4,

Figure 6 shows a schematic arrangement in which one of the eyes is shown in cross section, Figure 7 is a part sectional view of a dolls head showing the eyes turning left,

Figure 8 is a part sectional view of the head of Figure 7 showing the arrangement by which the eyes and the head can be made to move simultaneously.

Figure 1 illustrates schematically the arrangement by which it is possible to detect and track an object within a spatial area "A" although it will be understood that the spatial area A may be considerably larger given that the orientation of the detector means can be changed by the actuator means. In the drawing there is shown radiation transmission means in the form of two LED emitters Tl, T2, two matching radiator detector means Dl, D2 each in the form of infrared detectors, control means shown generally at 1, pre-amplifiers 2 and 3 and an actuator means shown generally at 4. The control means 1 includes a subtractor 5 which is electrically connected to the pre-amplifiers 2 and 3, the connection with pre-amplifier 3 being labelled "L" and the connection with pre-amplifier 2 being labelled "R", corresponding respectively to left and right. Subtractor 5 carries out the function of subtracting the left and right signals from each other and producing a resultant signal to corresponding comparators 6, 7 indicating either that the left hand signal was greater than the right hand signal, in which case comparator 6 receives a signal from the subtractor 5, or that the right hand signal was greater than the left hand signal, in which case comparator 7 receives a signal from subtractor 5. In either event, comparators 6 and 7 are each connected to a controller 8 in the form of a microprocessor which includes means (not shown) to produce either no drive signal in the event that the subtraction carried out by subtractor 5 results in zero output or substantially zero output, or a turn left drive signal or a turn right drive signal for the actuator means 4.

The actuator means comprises an electrical motor

9 and drive linkages 10 (described in detail in Figure 7) mechanically connected to the detectors Dl, D2 in such a manner as to permit the relative orientation of the detectors with respect to the object "O" to be adjusted.

It will be apparent from Figure 1 that when radiation is emitted from emitters Tl, T2 and is reflected off object 0 part of the reflected radiation is detected by each of the detectors Dl, D2 and it will be further apparent that when the object 0 is in a position generally orthogonal to the detectors then the relative strengths of the electrical signals generated by each detector will be generally equal, thus indicating that the object is directly in front. In this condition the subtraction function carried out by the subtractor 5 produces no resultant signal and hence no drive signal are provides to the actuator means 4 whereby the relative orientation of the detectors to the object O would be changed.

However, in the event that the object O were to be in a position other than that as shown e.g. to the left (as depicted in outline) or to the right of a line orthogonal to the detectors it will be apparent that there will be a corresponding difference in the intensity of the reflected signals and hence the signals received by the detectors resulting in a corresponding difference in the level of electrical power generated by each detector. In the position shown in outline detector D2 receives more radiation than detector D and hence produces a correspondingly higher electrical output. In these circumstances the subtractor 5 produces a signal which is fed to comparator 7 indicating a strong left signal and, in turn, the controller 8 provides a corresponding drive signal to the actuator means 4. Since the actuator means is connected to the detectors the detectors Dl and D2 are moved simultaneously until both detectors are generally point to the object from which radiation emitted by emitters Tl and T2 is being reflected. Of course, in the event that the object O is continuously moving within the area A then the detectors will also move correspondingly once having locked upon the object until the object exits from the area A, or stops moving. The logic circuitry contained in the controller 8 is entirely conventional and has not been described in detail but it will be apparent to those skilled in the art that various refinements can be made to provide a relatively sophisticated system whereby the apparatus can be operated with a set of defined parameters. For example, the emitted radiation may be codified so that it may be differentiated from extraneous signals when detected by the detection means. Similarly, the pre-amplifiers may incorporate filters to discard relatively weak signals such that only relatively strong reflection signals indicating a body fairly near to the apparatus within the spatial area A is detected.

The circuitry may also include means to compare the strength of both sets of signals emanating from the pre-amplifiers from previously stored signals from the pre-amplifiers to determine whether the signals are fading or becoming stronger over time, thus indicating that a body within the area A is moving towards or away from the apparatus. In such circumstances the control circuitry may also include response signals to, for example, provide for an audio response when the object is approaching or moving away from the apparatus. In the event that the apparatus is incorporated within a toy doll such an audio response could be a word or a string of words such as

"Hello, my name is ", or upon the object leaving the audio response could be "good-bye etc.".

Further refinements of the system are possible by suitable configuration of the controller 8 to provide responses such as lighting control, speech synthesis or the turning on of any electrically operated devices.

In Figure 2 there is shown a schematic arrangement whereby two dolls eyes 11, 12 are each provided with emitters Tl, T2 and detectors Dl, D2 positioned behind the emitters and being capable of receiving reflected radiation emanating from the emitters Tl, T2 in a manner to be more fully described with reference to Figure 6. Each of the eyes 11, 12 are connected by means of a linkage 13 which in turn is secured upon a rotatable shaft 14 connected to a motor 15. The linkage 13, shaft 14 and motor 15 are included within the definition of actuator means 4.

In Figure 2 it will be seen that the emitters Tl, T2 each combine to produce beams of radiation each of angle θ and during movement of the eyes 11, 12, these combined beams will move left or right as the case may be.

In Figure 3 is a side view of one of the eyes of Figure 2 which illustrates the relative orientation of that part of the actuator means 4 connected thereto.

In Figures 4 and 5 is schematically shown the operation of the scanning mode of the two eyes. In Figure 4 it will be seen that the eyes 11, 12 are being rotated anti-clockwise so that the beam of radiation emitted by each of the emitters Tl, T2 is being swept over part of the spatial area and is just about to impinge upon an object O. In Figure 5 the two eyes have "locked" upon the object in the sense that the detector means Dl, D2, by virtue of the fact that they are incorporated to the rear of each of the eyes, have been placed in a position whereby they can each receive generally identical amounts of radiation reflected of the object, thus indicating that the object is directly ahead of the eyes. In this configuration, each of the detectors Dl, D2 is orthogonal to the object and therefore provide roughly equal signals so that the subtractor 5 referred to in Figure 1 will essentially produce a zero result and hence the actuator means 4 will be deactivated.

In Figure 6 is shown a partial cross section of an eye arrangement which comprises a generally solid plastics eye ball 16 adapted to be rotated about an axis line between an upper peg 17 and a lower peg 18. Lower peg 18 has a projecting part 19 of reduced diameter, which is received within a correspondingly shaped hole (not shown) on the end of a pivotable arm 20, described in more detail in Figure 7 and 8.

Within the central portion of the eye there is disposed, as can be seen, a detector Dl and an emitter Tl, the emitter Tl being placed centrally within a conventional lens 21 of transparent material, such as acrylic. Emitter Tl is optically insulated by means of an opaque sleeve 22 such that it can only project radiation forwards of the eye in the manner as shown in Figures 2 and 3. Between the lens 21 and detector Dl is a cavity 23 of frusto-conical section having on the surface thereof a blue-tinted metallic coating 24. It will be apparent that when the eye is viewed from the front, it will appear as a blue eye because of the presence of the coating 24 but the coating 24 also performs the important function of tending to reflect off the surface extraneous light being directed into the cavity 23 by the lens 21 so that as much incoming radiation as possible is received onto the detector Dl. Because the emitter Tl only occupies a relatively small part of the total cross-section covered by the lens 21 it will be apparent that the invention provides means whereby the emitter and the detector are each placed in a position within the eye which is unobtrusive and thus aesthetically pleasing. Various other coatings apart from a blue tinted coating could be used and, similarly, the lens 21 may be either clear or may itself be tinted a desired colour to mimic a required eye colour. Similarly, although a refractive lens is described it will be apparent that other types of lenses, such as catadioptric lenses, could also be used if it is desired e.g. to have a folded-optics system for compactness.

Turning now to Figures 7 and 8 there is shown an arrangement whereby the eyes of the doll are enabled to move left and right with respect to the head but, additionally, the head is also adapted to move left or right with respect to the body of the doll. Figure 8 corresponds to a view taken generally along the section AA of Figure 7 and Figure 7 corresponds to a view taken generally along the Section BB of Figure 8. In the drawings it will be seen that the eyes 11, 12 are connected to each other for simultaneous movement by means of a linkage 25, the free ends of which are received within correspondingly shaped holes in each respective arm 20 connected to each eye. The left eye 12 has an additional arm 26 which itself is connected to a central arm 27 by means of a further linkage 28. The central arm has a pair of ears 29, 30 and is received upon a central shaft 31 connected as can be seen more clearly in Figure 8 to the motor 9 housed within the body of the doll (only part of which is shown) . Shaft 31 is received within a correspondingly shaped tube 32 forming part of the skull 33 of the doll's head. The upper end of the tube 32 (part of which is shown cut away) includes a pair of upright tabs 34 such that the space between the tabs 34 defines a slot within which the end of the central shaft 31 and the two ears 29, 30 of the central arm 27 can rotate within the limit made possible by the existence of the tabs 34.

In operation it will be apparent that rotation of the shaft 31 in either direction initially causes the eyes 11, 12 to move within the skull 33 to the limits defined by the amount of movement of the ears 29, 30 permitted by the existence of the tabs 34, after which further rotation of the shaft 31 induces rational movement of the skull 33 in either direction. In Figure 7 it will be seen that the limit of movement of the eyes 11, 12 within the skull 33 has been reached and further rotation in an anti-clockwise sense of the shaft 31 will thereafter induce movement of the entire skull 33. In this manner, the head of a doll can be made to move very realistically, at first by means of its eyes following an object within the spatial area covered by the tracking apparatus, and then by the head appearing to turn in the same direction until either the object has stopped, whereupon the eyes can become centralised by means of suitable drive signals being generated by the controller 8, or it can reverse direction and carry out a sweep function to try to locate objects within the spatial area.

The invention in its many aspects is capable of being applied in different circumstances and, for instance, it is not strictly necessary for the detectors Dl, D2 • to move at all if, instead, some optical, for example an end of an optical fibre, linkage were devised by which eyes or the like could be made to point at an object being tracked within the spatial area, or to sweep over the spatial area at recurrent intervals provided that the detectors are able to receive amounts of radiation corresponding to the orientation of the eyes or such like to the object. Similarly, it is not necessary to have two independent transmitters Tl, T2 since even one transmitter, providing it is sufficiently powerful, would enable sufficient radiation to inpinge upon an object so that the reflected signal is sufficiently strong to be picked up by the detectors. However, at least two detectors must be used in the apparatus according to the invention since it is necessary to compare one signal from the other in order to determine the general direction of the strongest signal and hence the general direction of movement required of part or all of the detector means.

T e invention may also provide once or more extra sensory elements such as an infra-red pyrodetector tuned specifically to receive wavelengths typically emitted as a result of animal or human body heat. This can then be used to determine if the apparatus is detecting a cold or warm object, and if the former, the apparatus may be adapted to ignore "cold" objects so as to realistically mimic the typical response of a baby or small child in differentiating between, for example, toy dolls and living persons or animals.

In this patent specification, and for reasons as aforesaid, the phrase "detector means" is not intended to be limited solely to the detectors themselves but is intended to encompass arrangements which generally point at least part of the detection means towards a required object, for example a gun of a toy tank or ship which may be optically coupled to the detectors which, as aforesaid, may or may not be adapted to move themselves.

Claims

CLAIMS :

1. Apparatus for detecting and tracking an object within a spatial area, comprising: radiation transmission means adapted to project radiation over the spatial area; at least two radiation detector means each being adapted to detect incoming radiation reflected from an object in the spatial area and to produce therefrom signals indicative of the amount of reflected radiation so detected; actuator means adapted to move part or all of each detector means to directions within the spatial area over which tracking movement thereof is desired; and control means for comparing the relative strengths of the signals generated by each detector means and depending on the result of said comparison for producing drive signals for driving the actuator means to orientate each detector or movable part thereof to perform said tracking.

2. Apparatus according to claim 1 wherein the at least two radiation detector means are matching and wherein the drive signals drive the actuator means to orientate each detector or movable part thereof to a position relative to the object so detected at which position the relative strengths of the resultant electrical signals generated by all detector means are generally equal.

3. Apparatus according to claims 1 or 2 further comprising a pre-amplifier for each detector means in order to amplify the signal generated thereby; and wherein the control means comprises comparator means to compare the respective strengths of each resultant signal from the pre-amplifiers with a preset reference signal corresponding to a minimum level of reflection from an object within the spatial area, and a means for determining whether or not to produce a drive signal for the actuator means and, if so, in which direction.

4 . Apparatus according to claim 1, 2 or 3 wherein the control means includes a clock function whereby real time signals received from the detector means are compared with previous signals to determine fi there has been any change thereof and, in the event that there has not, to produce drive signals whereby the detector means are driven by the actuator means to point to other parts of the spatial area covered by the apparatus in a scanning mode.

5. Apparatus according to any one of the preceding claims wherein the control means controls the actuator means to sweep the detectors or movable parts thereof in at least one direction and back continuously until an object is detected, and wherein when an object is detected the actuator means stop and the control means carries out an evaluative measurement to see if the object is moving and if the object is evaluated not to have moved within a predetermined period the control means emit a drive signal to the actuator to continue to sweep the detectors over the spatial area until an object is again detected.

6. Apparatus according to any one of the preceding claims wherein the radiation transmission means comprises one or more infrared emitters, and wherein the radiation detector means include infrared receiver means responsive to radiation of the same wavelengths as that emitted by the emitters.

7. A toy doll including apparatus according to any one of the preceding claims wherein there are two detector means, one being positioned in each eye of the doll, each eye being capable of movement left and right and/or up and down, said actuator means being adapted to move both of the eyes simultaneously left or right, or up or down as the case may be, in response to the drive signals being received from the control means.

8. A toy doll according to claim 7, wherein one radiation transmission means is placed centrally within the iris of each eye and insulated so as to prevent backwards or sidewards emission of radiation directly onto the detector means, and arranged to project a beam of radiation generally forward of the eyes wherein each eye includes a lens surrounding the radiation emitter being capable of focusing reflected radiation onto each respective detector means and wherein each eye includes a housing having an internal surface which is reflective of incoming radiation so as to maximize the strength of reflected radiation received through each eye and detected by the detector means.

9. A doll according to claim 7 or 8 wherein when the limit of travel of the eyes in any direction is reached the head continues to rotate in the same direction.

10. A method of detecing and tracking an object eithin a special area comprising the steps of: transmitting radiation to project over the special area; detecting with detection means, at at least two points, radiation reflected by an object in the spatial area; producing signals indicative of the detected signals and comparing them; and using the result of the comparison to cause at least some part of the detection means to direct itself towards the detected object in the spatial area.

11. Apparatus according to claim 1 substantially as herein described with reference to the accompanying drawings.

12. A toy doll according to claim 7 substantially as herein described with reference to the accompanying drawings.

13. A method according to claim 10 substantially as herein described with reference to the accompanying drawings.