Patent Publication Number: US-7905761-B2

Title: Remote controlled toy vehicle, toy vehicle control system and game using remote controlled toy vehicle

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a division of pending U.S. patent application Ser. No. 11/120,214 filed 2 May 2005, which claims priority to U.S. Provisional Application No. 60/422,728 filed 31 Oct. 2002 and International Application No. PCT/US03/34528 filed 31 Oct. 2003, the disclosures of which are all incorporated by reference herein in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to a remotely controlled battery powered toy vehicle which includes one or more vehicle mounted simulated weapons which may be employed for playing a single player or multi-user game. 
     Remotely controlled battery powered toy vehicles are generally well known. Such toy vehicles may take the form of a race car, truck, motorcycle, sport utility vehicle or the like or may include a fighting vehicle, such as a jeep, tank, hummer, etc. Additionally, incorporating simulated weapons into such remotely controlled toy vehicles, particularly such as a fighting vehicle is also generally well known. The present invention includes an improvement upon such known remotely controlled toy vehicles with such remotely fireable simulated weapons by incorporating from one to four such toy vehicles into an interactive game, where each of the vehicles may be separately controlled by different users for playing the game. 
     BRIEF SUMMARY OF THE INVENTION 
     One aspect of the present invention is, in a wireless controlled toy vehicle system having a plurality of at least two independently remotely controllable toy vehicles, each of the toy vehicles being independently remotely controlled by a separate, respective, associated hand-held manual wireless controller of a plurality of hand-held manual wireless controllers of the system, each of the plurality of toy vehicles having actuators for controlling the operation of the plurality of vehicles in accordance with control signals received from the associated, respective manual wireless controller of the plurality of manual wireless controllers, an improvement comprising: a first manually actuable wireless controller of the plurality being respectively associated with a first of the plurality of toy vehicles and generating a stream of first control signal packets in response to user manual inputs to the first controller, the stream of first control signal packets being transmitted to the plurality of toy vehicles during a first transmission window and coded to control only the first of the plurality of toy vehicles; and a second manually actuable wireless controller being respectively associated with a second of the plurality of toy vehicles and generating a stream of second control signal packets in response to user manual inputs to the second controller, the stream of second control signal packets being transmitted to the plurality of toy vehicles during a second transmission window and coded to control only the second of the plurality of toy vehicles, wherein the first and second transmission windows are time synchronized such that the streams of first and second control signal packets avoid time overlap of each other when transmitted to the plurality of toy vehicles while user inputs are being simultaneously manually entered into at least the first and second manually actuable wireless controllers. 
     Another aspect of the present invention is a method for controlling a plurality of at least two toy vehicles in a wireless controlled toy vehicle system ( 50 ), each of the toy vehicles of the plurality being remotely controlled by separate respective associated manually actuable wireless controllers, the at least two toy vehicles having actuators for controlling the operation of the at least two toy vehicles in accordance with control signals received from the respective associated manually actuable hand-held, wireless controllers, the method comprising: defining a series of sequential, repeated first and second transmission windows, each transmission window having a single, common transmission window length (TL); time synchronizing the first and second transmission windows such that the first and second windows do not overlap each other; generating a stream of first control signal packets; generating a stream of second control signal packets; of transmitting the stream of first control signal packets to the plurality of toy vehicles during the first transmission window to control only a first of the plurality of toy vehicles; and transmitting the stream of second control signal packets to the plurality of toy vehicles during the second transmission window to control only a second of the plurality of toy vehicles. 
     Another aspect of the present invention is an interactive toy vehicle game system comprising: at least one wireless controlled toy vehicle having a mobile platform configured to move over a playing surface, an on-board vehicle controller configured to control the at least one toy vehicle based on manual input from a player, at least one vehicle weapon mounted to the mobile platform and configured to fire on an enemy vehicle and at least one damage sensor mounted to the at least one toy vehicle and configured to detect hits on the at least one toy vehicle; and at least one mobile droid vehicle having a mobile droid platform configured to move over the playing surface, the at least one mobile droid vehicle having an enemy weapon mounted to the mobile droid platform and an on-board mobile droid controller configured to seek the at least one toy vehicle and fire the enemy weapon at the at least one toy vehicle; wherein the vehicle controller is further configured to disable the at least one toy vehicle when the vehicle controller detects collectively from each damage sensor of the vehicle a predetermined number of hits from the enemy weapon. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The following detailed description of preferred embodiments of the invention will be better understood when read in conjunction with the appended diagrammatic drawings. For the purpose of illustrating the invention, there is shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. 
       In the drawings: 
         FIG. 1  is a perspective view of a preferred exemplary embodiment of a toy vehicle in accordance with the present invention with a cover plate slightly raised; 
         FIGS. 2   a ,  2   b  and  2   c  are front, side and rear elevational views of a preferred embodiment of a radio controller in accordance with the present invention; 
         FIG. 3  is a functional block diagram schematic of the on-board vehicle control system of the toy vehicle of  FIG. 1 ; 
         FIG. 4  is a functional block diagram schematic of the circuitry of the radio controller of  FIG. 2 ; 
         FIG. 5  is a side elevational view of a portion of a simulated weapon; 
         FIG. 6  is an elevational view of an infrared receiver dome; 
         FIG. 7  is a schematic of the infrared sensor circuit; 
         FIG. 8  is a top perspective view of an alternative embodiment of a tag base having an encoded reflective pattern in accordance with the present invention; 
         FIG. 9  is a top perspective view of the game system according to the present invention; 
         FIG. 10  is a top perspective view of the game system according to an alternative embodiment of the present invention; 
         FIG. 11  is a flow diagram illustrating the operation of the service function MCU of  FIG. 3 ; 
         FIG. 12  is a flow diagram illustrating the receiver functioning of the DPLL MCU of  FIG. 3 ; 
         FIG. 13   a  is a table showing drive and fire data packets generated by a radio controller; 
         FIG. 13   b  is a diagram illustrating a stream of control signal packets; 
         FIG. 13   c  is a diagram illustrating the transmission windows and dead space between transmission windows of the time division multiplex communication scheme; 
         FIGS. 14   a ,  14   b  and  14   c  are flow diagrams illustrating the operation of a portion of the firmware of the transmitter circuitry of  FIG. 4 ; 
         FIG. 15  is a functional schematic block diagram of the control system of a mobile droid used in the present invention; 
         FIG. 16  is a perspective view of several preferred tag bases showing implementations of reflective patterns; 
         FIG. 17  is a flow diagram illustrating the functioning of the control system in reading and implementing a read reflective pattern; 
         FIGS. 18   a ,  18   b  and  18   c  are side elevational, top plan and exploded view of a border droid; 
         FIG. 18   d  is a functional schematic block diagram of the control system of a border droid used in the present invention; 
         FIGS. 19   a ,  19   b  and  19   c  are top plan, front elevational and side elevational views of a stationary droid; 
         FIG. 19   d  is a functional schematic block diagram of the control system of a stationary droid used in the present invention; and 
         FIG. 20  is a side view of a toy vehicle showing the tag reader in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention, in one embodiment, comprises a remotely controlled toy vehicle  10 . In the presently preferred embodiment, the remotely controlled toy vehicle  10  is in the form of a fighting vehicle such as a tank or other such armored vehicle, Humvee or the like, which moves over a surface  16 . The present invention is not limited to a remotely controlled toy vehicle having a particular shape, size, configuration or appearance. The remotely controlled toy vehicle  10  includes a mobile platform  14 , one or more battery powered electric motors  302 ,  304  ( FIG. 3 ) and associated gears, transmissions or other drive mechanisms and control circuitry ( FIG. 3 ) to permit the movement of the toy vehicle  10  in the forward or rearward direction and to permit the toy vehicle  10  to turn to the left or the right under the remote control of a user. Power for the toy vehicle is provided by one or more on-board batteries  306  which may comprise a rechargeable battery pack, individual rechargeable batteries, non-rechargeable batteries or the like. 
     The toy vehicle  10  further includes an on-board control system, or central vehicle hand-held, controller  300  ( FIG. 3 ) which is employed for controlling at least one aspect of the toy vehicle  10 , such as movement of the vehicle, based at least in part upon control signals received from a wireless, preferably, radio remote controller  12  ( FIGS. 2   a - 2   c ). The remote controller  12  is preferably manually operated by a user and configured to remotely control user selected movement of the toy vehicle  10 . Thus, the toy vehicle  10  does not adhere to any defined movement such as, for example, movement along a track. In the presently described embodiment, control signals are transmitted from the radio controller  12  to the central controller  300  of the toy vehicle  10  using radio technology and a control scheme which will hereinafter be described in greater detail. However, any other suitable form of transmission technology, particularly optical such as infrared, could alternatively be employed for controlling the operation of the toy vehicle and a different control scheme could also be used. “Wireless” refers to the communication channel(s) between the hand-held user operated, remote controller and the toy vehicle being controlled. Additionally, the toy vehicle  10  and radio controller  12  may be utilized in a game system having multiple toy vehicles  10 , each having their own, separate associated radio controller  12  for remote radio control of the corresponding toy vehicle. 
     Control Scheme 
     In the presently preferred embodiment, firmware control of the toy vehicle  10  of  FIG. 1  operates entirely in the foreground; that is on a non-interrupt basis with a series of scheduled service routines at predetermined, scheduled times. In the preferred embodiment, the on-board toy vehicle control system  300  includes a service function microprocessor MCU  316  model SPC 215B which runs at a speed of six MHz. The MCU  316  may be any microprocessor known in the art capable of performing the tasks associated with the control system  300 . Running the MCU  316  at 6 MHz allows the firmware to perform all of the required service routines on a non-interrupt basis at regularly scheduled times. The required on-board firmware functions which must be performed can be divided into three categories; functions that must happen at 8 kHz, functions that must happen at about 1 kHz, and functions that may happen less frequently (i.e., less than 100 Hz) and with less precision of scheduling (i.e., plus or minus tens of milliseconds). The basic loop “service” time for the MCU  316  is preferably 125 microseconds (8 kHz) to allow all of the required functions to be serviced at the required time intervals without overlapping. For example, the sound function is serviced at 8 kHz (four times per service loop) while the infrared hit detection, infrared gun and optical tag read functions are all serviced at 8 kHz (20 percent of the time the gun function happens at 8 kHz, 80 percent of the time it is not serviced), the various functions are alternated so they are all serviced at a minimum of the frequency as shown in the diagram of  FIG. 11 . 
     Running the MCU  316  at 6 MHz allows the firmware to perform all of the required service routines with each service routine being performed no more frequently than is necessary. Sufficient additional time is available for making changes in the routines without changing the speed of the microprocessor. 
     The central controller  300  further includes a separate microprocessor, preferably a DPLL MCU  328 , for receiving and decoding control signals received from the radio controller  12  in a manner which will hereinafter become apparent. An oscillator  330  which may be a crystal oscillator, RC oscillator, external oscillator or the like, is included for establishing the timing of the service function MCU  316  and the DPLL MCU  328  in a manner well known to those of ordinary skill in the art. Each central controller  300  further includes a vehicle identification switch  332 , which may be set to any one of several different positions to discriminate between different toy vehicles  10  used in playing a game. As shown in  FIG. 3 , the central controller  300  includes an on/off power switch  334  and a voltage regulation circuit  336  for providing regulated voltage to the various other systems and subsystems of the central controller  300 . 
     The exemplary toy vehicle  10  includes a suitable antenna  338  for receiving radio frequency signals from the remote radio controller  12 . The antenna may be hidden under or within the body of vehicle  10 . Output signals from the antenna  338  are sent to a receiver/demodulator  340  for demodulation of the received radio frequency signals. Output signals from the receiver/demodulator  340  are fed to the DPLL MCU  328  through a high gain differential amplifier  342 . The DPLL MCU  328  receives and decodes the instruction signals in a manner as illustrated by the flow diagram of  FIG. 12  and as is well known to those of ordinary skill in the art. Further details concerning the structure and operation of the various components and subassemblies of the on-board central controller  300  are well known to those of ordinary skill in the art and available from a variety of sources. 
     Communication Scheme 
       FIG. 4  is a schematic block diagram of a preferred embodiment of the circuitry  400  employed within the remote radio controller  12 . The circuitry  400  of the radio controller is generally typical of remote control units known to those of ordinary skill in the art for controlling the operation of a remotely controlled toy vehicle. Accordingly, while  FIG. 4  illustrates a presently preferred embodiment of the remote control circuitry  400 , it should be understood by those of ordinary skill in the art that the communication system or scheme could be implemented in some other manner, if desired. The remote control unit circuitry  400  includes an encoder portion having a microprocessor  410  employed for generating a stream of control signal packets for controlling the operation of the toy vehicle  10 . The microprocessor  410  is preferably of a type already used and well known to those of ordinary skill in this art. The remote control circuitry  400  is powered by a battery, preferably a 9-volt battery  412  which may be of the rechargeable or non-rechargeable type. Power from the battery  412  is applied to the microprocessor  410  through a suitable voltage regulator  414  also of a type well known to those of ordinary skill in the art. The battery  412  also provides power to the other components and subassemblies of the control circuit shown in  FIG. 4 . A light emitting diode (LED)  416  is employed for providing to a user an indication of the remaining battery power. 
     In the present embodiment, bi-phase encoded bits are used with each bi-phase encoded bit being of the same predetermined width and employing a fifty percent duty cycle including two transmit elements per encoded bit. Another form of encoding and/or a different duty cycle could be employed, if desired. In the present embodiment, one binary state, binary “0”, is defined as both of the transmit elements of a bit being the same and the other binary state, binary “1”, is defined as both of the transmit elements of a bit being opposite. The use of such a bi-phase encoding scheme is beneficial in that it permits reading of the state of a bit by reading the center portion of each transmit element. The state (high or low) always changes between bits. 
     Referring to  FIG. 13   a , in the present embodiment there are two types of data packets, a “drive” data packet and a separate “fire” data packet. Each drive data packet  132  preferably includes a single, unchanging, six bit drive flag  133 , in the present embodiment 011110, followed by seven bits of drive data  134  (e.g. ID 1 , ID 0 , turbo, forward left, reverse left, forward right and reverse left) depending on the user selection of the direction and speed of movement of the toy vehicle  10 . Similarly, in the present embodiment, each fire data packet  136  preferably includes a single, unchanging six bit fire flag  137  (011111), followed by seven bits of fire data  138  (e.g. ID 1 , ID 0 , EM, HG, ping, forward fire and rearward fire) depending on the user selected fire options. The radio controllers  12  transmit the control data packets  132  or  136  in a steam  140  of packets (see  FIG. 13   b ). Since no check sum bits are used, the presently preferred embodiment relies upon the receipt of two or more identical data packets  132  or  136  as verification of the validity of the received drive and/or fire data. 
     In addition, with the presently preferred embodiments, if the user has not selected vehicle movement or the firing of a weapon, no corresponding data packets are transmitted. For example, if the user is moving the toy vehicle  10  without firing a weapon, only the drive data packet  132  will be continuously transmitted whereas if the toy vehicle  10  is not moving, only the selected fire data packet  136  will be continuously transmitted. If the toy vehicle  10  is firing a weapon while moving both the drive data packet  132  and the fire data packet  136  will be transmitted in an alternating pattern, as shown in  FIG. 13   b.    
     In addition to the microprocessor encoder  410 , the circuitry  400  of the manually actuable controller(s)  12  includes a plurality of control switches or user manual inputs  418 ,  420 , which are manually activated by a user for controlling the operation of the toy vehicle  12 . In the present embodiment a “D-pad”  420  is used for controlling the movement of the toy vehicle  10  (forward, backward, left, right) and additional control switches/buttons  418  are employed for controlling the firing of the simulated weapons on the toy vehicle  10 . The user controlled switches  418 ,  420  may alternately be in the form of lever switches, push button switches, a joy stick or the like. The position of each of the D-pad  420  and fire control switches  418  generates signals which are employed as inputs to the microprocessor encoder  410  which in turn uses the inputs to “encode” the signals by generating the signal packets. As long as the D-pad  420  and fire control switches  418  remain in the same positions, the microprocessor  410  continuously generates the same control signal packet as a stream of packets  140 . If the position of any of the control switches changes, the microprocessor  410  senses the change and generates a series of new control signal packets. If neither the D-pad  420  nor any of the fire control switches  418  are active, no control signals are transmitted. 
     Each remote radio controller  12  includes a vehicle identification switch  436  having an output which is encoded and transmitted within each control signal packet  132 ,  136  and which when received is decoded and compared to the position of the output of the vehicle identification switch  332  in the central controller  300  for identity comparison purposes. The codes from the vehicle identification switch  436  are transmitted in each control data packet  134 ,  138 , such that each control signal packet includes a vehicle identification tag (ID 1 , ID 0 ) which associates each control signal packet with the toy vehicle  10  associated with that remote radio controller  12 . Further details concerning the manner in which signal packets are set up for controlling a remotely controlled toy vehicle may be obtained from co-pending U.S. patent application Ser. No. 10/046,374, filed Jan. 14, 2002, now U.S. Pat. No. 6,848,968 the complete disclosure which is hereby incorporated herein by reference. 
     The radio controller  12  also includes a transmitter, in the presently preferred embodiment a radio frequency transmitter including an oscillator  422 , a crystal  424  for the oscillator  422 , a radio frequency amplifier  426 , a matching circuit  428  and an antenna  430 , for transmitting the generated control signal packets  132 ,  136  to the toy vehicle  10 . It will be appreciated by those of ordinary skill in the art that some other type of transmitter, such as an infrared transmitter, could alternatively be employed. 
     Time Division Multiplexing Scheme 
     As stated above, the present invention comprises a game in which as many as four toy vehicles  12 , each under the control of a different user, are simultaneously employed to play against each other. Accordingly, each toy vehicle  12  must be separately and independently controlled from each of the other toy vehicles without incurring interference between control signals. In the present embodiment, the streams of control signal packets are transmitted on the same carrier radio frequency for all four of the vehicles. Therefore, time-division multiplexing (TDM) is employed, with each controller being assigned a separate transmission “window”  141 ,  142 ,  143 ,  144 , respectively, during a prescribed time cycle TC. The time cycle includes sufficient “dead” time  146  between the transmission windows so that there is no overlap between the transmission windows, even over the course of the game as windows slowly drift relative to one another. The use of time-division multiplexing requires synchronization and calibration of the several radio controllers  12  to calibrate/adjust for different crystal speeds at the beginning of play so that the transmission windows for each radio controller  12  are scheduled to happen at different times in order to avoid transmission collisions. 
     From experience it is known that a toy vehicle  10  must receive an updated control signal packet from its corresponding radio controller  12  approximately every 100 milliseconds. At a slower update rate, the toy vehicle  10  behaves sluggishly. This means that for four vehicles to be controlled using the same frequency and to avoid collisions, each toy vehicle  10  can be allotted a transmission window which is no larger than twenty-five milliseconds. Since, during play, some drift in the transmissions may occur due to the normal timing drift, the actual control signal packet length must be less than twenty-five milliseconds. 
     In the present embodiment, eighty-eight milliseconds has been chosen as the time of a complete transmit cycle TC. Within the eighty-eight milliseconds, each transmitter (e.g., radio controller  12 ) has fourteen milliseconds of transmission, such that transmission windows have a single, common transmission window length TL, followed by seventy-four milliseconds of non-transmission as shown in  FIG. 13   c . Between each transmission window  141 ,  142 ,  143 ,  144  is an eight millisecond period of dead time  146 . By providing an eight millisecond dead time, a transmission window may drift up to eight milliseconds in either direction relative to the adjacent window without colliding with the transmission of another control signal packet  132 ,  136 . 
     In the prior art are remote control toy vehicles using bi-phase encoding with each transmit element comprising one-half of a bit, a typical bit rate of 1.5 kilobits per second (transmit element of 333 microseconds). In order to accommodate the required control signal packet as well as the time division multiplexing scheme, the bit rate for the presently preferred embodiment has been increased to six and one half kilobits per second—each transmit element having a width of seventy six and one half microseconds. By increasing the bit rate in this manner, three and one-half control signal packets  132 ,  136  can be sent in each fourteen millisecond transmission window  141 ,  142 ,  143 ,  144 . Since one-third of a control signal packet is required for synchronization of the hardware and firmware (referred to as warm up), essentially six complete control signal packets  132 ,  136  may be sent during a given transmission window. If at least two sequential control signal packets are identical when received and decoded by the central controller  300 , the received control signal packets are considered to be valid and the operation of the toy vehicle  10  is actuated accordingly. When transmitting both drive data packets  132  and fire data packets in alternating fashion in the same stream  140  ( FIG. 13   b ), the received control signal packets will be deemed valid if the next sequential packet of the same type is identical. Sending multiple control signal packets in the same transmission window in this manner is desirable because it permits packet level error checking, thereby significantly reducing transmission error. 
     In order to avoid transmission collisions, the radio controllers  12  must be synchronized at the beginning of play so that their transmissions are all scheduled to happen at the appropriate, spaced times. The transmission windows must also not drift during play to the extent that transmissions from two or more of the remote radio controllers  12  could overlap. Synchronization is accomplished by physically plugging together the up to four remote control units prior to transmission of streams of control signal packets (i.e., prior to the beginning of play) using a pair of synchronization ports  432 ,  434  on each radio controller  12 . Once the four remote radio controllers are plugged together, they are turned on and a synchronization button (not shown) on one of the radio controllers  12  is depressed to initiate the synchronization process. The radio controller on which the synchronization button is depressed becomes the master and generates a timed pulse on a synchronization line. The other radio controllers are considered to be “slave” units and use the timed synchronization pulse to establish their respective transmission windows at a fixed amount of time after the end of the master synchronization pulse depending upon the identity of the radio controller and to calibrate their processor speeds relative to the processor speed of the master in order to adjust for drift. The slave radio controllers calibrate by measuring the synchronization pulse and using the difference between the measured pulse length and the nominal pulse length (how long the pulses would be if the remote control units ran at exactly the same speed) to calculate an adjustment. During normal play, the slave remote radio controllers use the calculated adjustment to minimize drift. After calibration is completed, the radio controllers move into normal operation.  FIGS. 14   a ,  14   b  and  14   c  are flow diagrams that illustrate the synchronization process. 
     Weapons 
     The preferred exemplary toy vehicle  10  further includes a simulated weapons system indicated generally at  308  compromising at least one remotely controlled “weapon” simulative of a weapon employed in an actual fighting vehicle. In the presently preferred embodiment, the toy vehicle  10  includes a first light cannon-like weapon in the form of a front firing narrow beam infrared emission source  310  and a second light cannon-like weapon in the form of a rear firing broad beam infrared emission source  312 . The front emission source weapon  310  is used for long range narrow beam targeting while the rear emission source weapon  312  is used for short range spread beam targeting. Preferably, both infrared emission source weapons  310 ,  312  operate with a carrier modulation frequency of about 40 kHz and with a physical optical wavelength of between about 880 and 900 nm. Other modulation frequencies and/or optical wavelengths may be employed. The front firing emissions source weapon  310  preferably uses a narrow half power beam angle infrared light emitting diode (LED)  510  ( FIG. 5 ) of a type well known in the art which is aligned with a single convex lens  520  to create an effective focal length in the range of 35 mm. Preferably, the lens  520  is made out of an acrylic material and is separated from the infrared LED  510  by about 38 mm. As a result, the front emission source weapon has the capability of “firing” an infrared beam up to about 4.25 meters (fourteen feet) with the beam including a diameter, at 4.25 meters, of about 115 mm. 
     The rear emission source weapon  312  also includes an infrared LED. However, because no focusing lens is provided, the range of the rear emissions source weapon is limited to approximately 0.8 to 0.9 meters (about three feet or less) and the diameter of the infrared signal at 0.85 meters is approximately 0.6 meters. Thus, the front firing emissions source weapon  310  may be used for firing precise beams over relatively long distances whereas the rear firing emission source weapon  312  is capable of firing a much wider beam path but only for a relatively short distance. The firing of both the front firing emission source weapon  310  and the rear firing emission source weapon  312  is controlled by a user using one or more appropriate manual control buttons on the hand-held remote control unit  12  in a manner which will hereinafter be described in greater detail. The infrared beams fired by both the front firing emissions source weapon  310  and the rear firing emission source weapon  312  may be used when playing a game to simulate the damaging or destruction of other toy vehicles playing the game in a manner which will hereinafter be described. The front firing emission source weapon  310  and the rear firing emission source weapon  312  can be activated regardless of whether the toy vehicle  10  is stationary or moving and without regard to the direction of movement of the toy vehicle  10 . 
     Damage Sensing 
     The toy vehicle also includes one or more infrared receiver modules, or “damage sensors”  314  for sensing when the toy vehicle has encountered a “hit” as a result of receiving an infrared beam “fired” by an enemy weapon from an “opponent” (i.e., another toy vehicle or an autonomous enemy game piece). In one embodiment of the toy vehicle  10 , four separate infrared sensors are provided one each on the front, rear, left and right sides of the toy vehicle.  FIG. 1  shows the damage sensors  22 ,  24  on the rear and right side of the toy vehicle  10 , respectively. The infrared damage sensors may be conventional IR optical receivers or any other element generally known in the art to detect a directed light beam. 
     In another embodiment, a generally transparent infrared receiver dome  530  ( FIG. 6 ) is located on the top or upper surface of the toy vehicle  10 . The receiver dome  530  includes a generally semispherical transparent cover  532  preferably made of an acrylic transparent material which encloses and covers a substantially conical reflective surface  534  having a central axis of rotation  536 . The apex of the conical reflective surface  534  faces downwardly into the toy vehicle  10 . The conical reflective surface  534  preferably has a base of approximately 25 mm and an angle of approximately 30°. Other angles and base dimensions may be employed. A single infrared receiver module, or damage sensor  314  with a center frequency which corresponds to the frequency of the infrared emissions source weapons  310 ,  312  is located within the toy vehicle  10  at a predetermined distance beneath the apex of the conical reflective surface  534 . In this manner, the combination of the conical reflective surface  534  and the transparent dome  532  cooperate to focus and direct downwardly toward the infrared sensor  314 , infrared light  538  received from any generally horizontal direction. This arrangement blocks a large percentage of downwardly directed extraneous background radiation that would otherwise saturate or adversely affect the damage sensor  314  yet allows generally horizontally traveling infrared signals, such as the type of signals that would be emitted by the simulated weapons  310 ,  312  from an opponent to be focused and reflected onto the infrared sensor  314  within the toy vehicle  10 . Preferably the infrared sensor  314  or receiver is a PIC 1018 available from Waitrony Co. Limited of China and Hong Kong. Upon receipt of an infrared signal, the damage sensor  314  within the toy vehicle  10  provides an electrical output signal to a microprocessor control unit (MCU)  316  of the control system  300  on board the vehicle  10 . The damage sensor  314  outputs demodulated digital signals, a “1” or a “0” based upon whether the received infrared radiation exceeds predetermined amplitude threshold criteria. In this manner, infrared noise within the playing area is not sufficient to produce an output signal unless its amplitude exceeds the threshold criteria, the modulation falls within the bandpass characteristics of the sensor and the wave length of the source is within the operating characteristics of the sensor. 
       FIG. 7  is a circuit diagram of the infrared sensor circuitry. The MCU  316  of the control system  300  on board the toy vehicle  10  determines, based upon the signal received from the damage sensor  314 , the extent of the simulated damage sustained by the toy vehicle  10  as a result of being “hit” by the infrared beam from the weapon of an opponent. The complete destruction of a toy vehicle  10  may end a game, at least for the player whose toy vehicle  10  received the hit whereas a toy vehicle  10  which has received only minor or collateral damage may be permitted to continue to play the game, perhaps with a penalty. 
     Tag Bases 
     The game with which the toy vehicle  10  is used contains at least one “tag base” such as exemplary tag base  160  ( FIG. 16 ) and preferably a plurality of tag bases which are strategically placed at selected locations throughout the area or playing surface  16  on which the game is to be played ( FIG. 9 ). The tag bases  160  are formed of tags  161  placed on a generally flat mat or pad  163  which is sufficiently thin to be driven over by a toy vehicle  10 . Each pad  163  has at least one tag  161  on an upper surface  165  thereof. Preferably, each tag  161  is small (no larger than 4″×4″), symmetrical, about the thickness of a sheet of paper and made of a polymeric material. In an alternative embodiment, several tags  161  may be removeably placed on or integrally formed with a substantially larger mat or pad  163 ′ which forms the playing surface  16  on which the game is played. Because the tag bases  160  are of the passive type, no separate power supply is required. 
     Each tag  161  incorporates a readable, pre-determined reflective pattern  162 , or barcode, which is encoded with information  170  which, in the preferred system being described, identifies an operational mode  350  of the toy vehicle  10  that is associated with the tag base  160 . As shown in  FIG. 16 , the reflective pattern  162  in a preferred embodiment is formed by a series of “marks”, or substantially non-reflective portions  164  which are separated by or interspaced with a series of “spaces”, or more highly reflective portions  166 . The marks  164  are implemented by a rough textured substantially non-reflective (e.g. matt) surface, which functions to scatter light. The spaces  166  are implemented by a more highly polished or reflective surface which reflects light. The reflective pattern  162  and at least the surface  165  within the pattern and/or the pad  163  are preferably monochromatic meaning marks and spaces between them are the same color. Monochromatic is intended to include monotonic (e.g. all back, all white or all gray). 
     The pattern of the marks and spaces of the reflective pattern  162  of a tag  161  are the same in the two principal opposing directions x, y (left or right when viewing  FIG. 16 ), such that the pattern  162  may be read as the toy vehicle  10  passes over the pattern  162  from either principal direction x, y. Stated differently, the pattern  162  on a tag  161  is symmetrical about a central axis  168 . 
     In the preferred embodiment, the toy vehicle  10  preferably includes a downwardly looking tag reader  318 , such as an infrared bar code scanner, mounted to the mobile platform  14 . The tag reader  318  preferably includes an IR emitter, or light transmitter  320 , an IR collector or optical receiver  322  (see  FIG. 20 ) and an amplifier  324 . The emitter  320  and the receiver  322  are mounted within the toy vehicle  10  at angles such that the light beams associated with the emitter  320  and receiver  322  intersect each other such that the tag reader  318  is at the appropriate distance from the surface  16  for reading the pattern  162 . The optical receiver  322  is preferably configured to read the reflective pattern  162  when the toy vehicle  10  traverses the reflective pattern  162  in a direction which is generally perpendicular to the central axis  168  (i.e., either of the two principal directions x, y). Thus, since the reflective pattern is symmetrical about the central axis  168 , the tag reader  318  may read the reflective pattern  162  when the toy vehicle is when moving in either a forward or rearward direction over the tag base  160 . By having the toy vehicle  10  pass over the pattern  162  of a tag base  160  within a prescribed angle of either of the two principal directions x, y (left or right), the pattern  162  may be read by the infrared tag reader  318  for enabling the particular feature or operational mode associated with the pattern  162  read from the tag  161 . Since a tag  161  has marks  164  and spaces  166  which have differing light reflecting qualities as described above, the ability of the tag reader  318  to differentiate between the marks  164  and spaces  166  and thus “read” the pattern  162  is enhanced. 
     The tags  161  include coded information  170  which is associated with one or more operational modes  350  of the toy vehicle  10 . The toy vehicle has a variety of modes which, when activated or deactivated, collectively define the vehicle&#39;s powers and/or capabilities. For example, one operational mode may grant the toy vehicle a particular armor strength or level. Additional categories of operational modes include weapons strength, speed and steering capabilities, fuel levels and the ability to employ hazards for an opponent. At least one of the numerous operational modes of the toy vehicle is altered when the vehicle passes over a tag base  160 , thereby giving the toy vehicle an advantage (or disadvantage) in playing the game, at least for a pre-determined time period, with respect to other opponents in the game. The vehicle(s)  10  might start with only nominal rather than maximum characteristics including speed/steering which can be maximized or minimized by passage over a tag base. For example, passing over a tag base may create stronger armor for the toy vehicle  10  causing it to be less susceptible to sustaining damage when attacked by another toy vehicle. Alternatively, the tag base  160  may give the toy vehicle  10  the capability of employing a hazard, such as an oil slick from the rear of the toy vehicle, or other weapon/defensive advantages causing any pursuing vehicles to lose steering control, speed or otherwise become disrupted or disabled for a predetermined time period. This would be accomplished by having the rear firing emission source broadcast a coded signal (e.g. a pulsed signal) that could be received and decoded by the following vehicle(s) and cause such vehicle(s) to reprogram a disability into itself. Other special effects which add increased interest to the playing of the game may also be employed. 
     Preferably, each tag base  160  includes indicia (not shown) in the form of a color code or other marking (e.g. basic monotone colors) to provide a user of with knowledge of the operational mode (i.e., green for advantage or red for disadvantage) which may be obtained by having the toy vehicle  10  pass over the tag base  160 . 
     A flow diagram showing the operation of the control system  300  in reading a pattern  162  is set forth in  FIG. 17 . Output signals from the tag reader  318  are provided to the MCU  316  for processing. Whenever a tag base  160  is read utilizing a bar code reader  318 , a decoded output signal from the reader/receiver  318  is sent to the MCU  316  of the on-board vehicle control system  300  for implementation. The MCU  316  receives the decoded tag base signal (the coded information  170 ) and takes appropriate action for implementing the corresponding operational mode  350  or feature afforded by the tag base  160 . Implementing a new operational mode  350  as the result of reading a tag  161  has the effect of at least partially re-programming the central controller  300 . That is, when the central controller  300  determines what the coded information  170  from the tag  161  represents, the controller  300  partially alters the executable code which it uses to effect operation of the toy vehicle  10 . The manner in which the controller  300  is re-programmed is consistent with the new operational mode  350 . The toy vehicle  10  further includes a series of visible indicators such as LEDs  326  which are illuminated by the MCU  316  to show the user the status of the features or operational modes enabled or actuated. 
     In an alternative embodiment, the tag bases  260  and tags  261  may have a generally circular shape, generally resembling a bull&#39;s eye design (see  FIG. 8 ). The tags  261  are similar to the tags  161  with the exception that the marks  264  and spaces  266  are formed from concentric rings around the center  268  of the pattern  262 . In this embodiment the optical reader  322  is configured to read the pattern  262  when the toy vehicle passes within a pre-determined distance of the center  268  of the pattern  262 . The advantage of bulls-eye tags is that they can be approached from any direction. The disadvantage is that the vehicle must pass over the tag much closer to its physical center than is necessary with the bar code tags  161 . It will be appreciated that either type of pattern (bar code of parallel bars  164 ,  166  and bull&#39;s eye of concentric rings  264 ,  266 ) will be read as long as the vehicle crosses the central axis of symmetry of the tag sufficiently perpendicularly to the central axis. For the bar code pattern  162  this means sufficiently close to parallel to the x, y directions and for the bull&#39;s-eye it means sufficiently close to the physical center of the bull&#39;s-eye. 
     It will be appreciated by those of ordinary skill in the art that the concept of employing a tag  161  for the toy vehicle  10  to pass over could be implemented using a technology other than the scanning or reading of a pattern. In addition, game features other than those specifically discussed above could also be employed. 
     One Player Games 
     In order to permit a single player/user to enjoy meaningful playtime with the toy vehicle  10 , the present invention further comprises separate, enemy (opponent) beam weapon firing toy devices in the form of “droids”. In the present embodiment there are three different types of droids: mobile droid vehicles, stationary droids and border droids. 
     Each mobile droid vehicle  60  takes the form of a mobile platform  62  (see  FIG. 9 ) configured to move over the playing surface  16 , preferably on wheels or rollers. The mobile droid vehicle further includes one or more enemy weapons  64  mounted to the platform  62 . The enemy weapon is preferably in the form of an infrared cannon which fires from the front of the mobile droid vehicle  60 . The mobile droid vehicle  60  further includes an on-board mobile droid controller  66  as shown in  FIG. 15 , which controls the operation of suitable drive and steering motors  69  as well as the enemy weapon  64 . The moving droid  60  may include tank-style steering to permit it to turn quickly in different directions. The controller  66  further includes a microcontroller  61  with a memory in which is stored a plurality of preprogrammed movement paths and preprogrammed firing sequences. In addition, the moving droid may be provided with a three position switch  67  that permits the player to set the defenses/“armor” on the moving droid to light, medium and strong. The moving droid further includes an infrared receiver, or droid damage sensor  68  mounted to the platform  62  for permitting the mobile droid vehicle to sustain damages from the simulated weapons of the toy vehicle  10 . The mobile droid controller  66  thus is configured to detect hits on the mobile droid vehicle  60  from the vehicle weapon of the toy vehicle  10 . The mobile droid  60  may further include a speaker  59  which emits sounds, for example, when firing or in response to a hit on the mobile droid. Additionally, LED indicators  58  may be provided to show the status (for example, damage level) of the mobile droid. The mobile droid is preferably powered by a battery  58 . A voltage regulation circuit  57  regulates power to the droid controller  66 . The mobile droid  60  may be turned on or off by the switch  56   
     The described mobile droid vehicle  60  is essentially self-contained and self-operating—i.e., no remote control unit is used with the moving droid. Once the moving droid is turned on and placed in the area of play, the mobile droid controller  66  moves the mobile droid vehicle  60  over the playing surface  16  in one of the predefined patterns  65  while firing the enemy weapon  64  according to its predetermined firing sequence. The toy vehicle  10  must then maneuver and fire its weapons to disable or destroy the moving droid before the moving droid effectively disables or destroys the toy vehicle  10 . Alternatively the mobile droid  60  can be configured to track the remotely controlled vehicle  10  in the manner described in U.S. Pat. No. 6,780,077 incorporated by reference herein in its entirety. 
       FIGS. 19   a ,  19   b  and  19   c  show a preferred embodiment of a stationary droid  70 . The droid  70  includes a non-mobile platform  72  which remains at a single location throughout the game. The stationary droid  70  includes a single rotating turret  74  mounted to the platform  72  and having simulated enemy weapon  76  in the form of an infrared beam firing cannon. The stationary droid  70  includes a stationary droid controller  78  shown in  FIG. 19   d , and includes a microcontroller  71 , a speaker  79  and voltage regulator  75 . The stationary droid is powered by batteries  73  and is turned on and off by the switch  77 . The turret  74  rotates along a predefined path  75  in opposite directions (oscillates) between two limits to establish a predetermined field of fire for the weapon  76  which is fired in a random or partially random manner as the turret  74  rotates. Once the stationary droid  70  is turned on and placed at a fixed location within the play area, it continues to rotate its turret and fires its weapon in the prescribed manner. A control switch or movable stops (not shown) on the stationary droid  70  permits a user to adjust the characteristics of rotation of the turret. The user must maneuver the toy vehicle  10  using the radio controller  12  to avoid being hit by “fire” from the enemy weapon  76  of the stationary droid  70 . 
       FIGS. 18   a - 18   c  show a preferred embodiment of a border droid  80  formed from a non-mobile platform  82 . The border droid  80  is similar to the stationary droid  70  as described above in that the border droid  80  does not move. However, unlike the stationary droid  70 , the border droid  80  has one and preferably two fixed simulated weapons  84 ,  85 , each of which is mounted to fire in a single, fixed direction. The firing directions of the two weapons  84 ,  85  are preferably perpendicular to each other but could be at other angles and could be adjustable. The weapons  84 ,  84  of the border droid  80  are both preferably infrared beam firing cannons and are fired randomly or partially randomly in their fixed directions to effectively establish or define a pair of intersecting border lines or boundaries within the play area. The border droid  80  includes a border controller  86 , shown in  FIG. 18   d . The border controller  86  includes a microcontroller  81 , a speaker  89  and a voltage regulator  83 . The border droid is powered by batteries  88  and is turned on and off by the switch  87 . Preferably, the border droid is placed at a corner  18  of the playing surface  16 , such that the weapons  84 ,  85  are aligned with two edges  17  of the playing surface  16 . Thus, the border droid  80  is used to construct the boundaries of a particular play area. A toy vehicle  10  is at risk of being hit if it attempts to cross either of the boundaries established by the border sentry droid  80 . 
     In playing a single player game, the player would initially place the moving droid in the middle of the play area, the stationary droid  70  at a desired location and the border droid  80  at the boundaries of the play area and scatter the tag bases  160  at various locations around the play area. The player would then turn on the mobile droid vehicle  60  and maneuver the toy vehicle  10  in a direction so that it could shoot and hit the mobile droid vehicle  60  while avoiding being hit by the mobile droid vehicle  60 , the stationary droid  70  and/or the border droid  80 . The toy vehicle  10  may be given a predetermined amount of time to seek out and destroy the mobile droid vehicle  60  before the toy vehicle  10  is disabled and defeated. The predetermined time can be set, for example, for a three minute, five minute or ten minute play time. When the moving droid has received sufficient damage, it can be preprogrammed to indicate it is defeated. For example, it may performs a 360° spin and then shuts down with a loud shut down sound. The toy vehicle  10  can drive around while attempting to attack the mobile droid vehicle  60  and avoid the other droids  70 ,  80  to run over the tag bases  160  to acquire the use of new weapons and/or other features to help the toy vehicle defeat the mobile droid vehicle. 
     Game Play—Multiple Players 
     In a game in which multiple toy vehicles (e.g. up to four) play against each other, each of the toy vehicles is initially placed within the play area of the toy vehicle system  50  (see  FIG. 10 ). Players or users control individual toy vehicles and compete against each other by attempting to kill one another utilizing the on-board simulated weapons. 
     Each of the toy vehicles  10  (and its associated simulated driver) may incorporate a separate appearance and styling and its own simulated “personality”. For example, each vehicle may have its own name (for example “Punisher”, “Technoid”, “Stalker”, “Scavenger”), its own preferred or default weapon (laser cannon, splatter gun, Gatling gun, rail gun) its own driving and/or firing sounds and other associated characteristics. Overall, the features of all of the toy vehicles should balance out to be relatively equal. For example, one toy vehicle may have a slightly more powerful weapons but with less speed or weaker armor, whereas another vehicle may be slightly faster but with a weaker weapon or weaker armor. Other features will be incorporated into the toy vehicles. For example, after firing a light weapon a predetermined number of times a “reload” period may be imposed during which a reloading sound will be heard and no firing is permitted. Heavy weapons can only be fired a small number of times unless “revived” be passing over a special tag base. 
     Players simultaneously try to avoid the fire from other vehicles and, possibly from an autonomous moving droid  60  in the field of play. Once defeated, a toy vehicle  10  is immobilized and credit for the kill can be claimed by another active toy vehicle. As vehicles accumulate kills or minutes of play experience, weaponry and/or mobility for the toy vehicle becomes more potent or robust. When a toy vehicle is killed by another toy vehicle, the dead vehicle will broadcast a “killed” signal through its front emission source weapon  310 . When another vehicle (the killing vehicle or some other vehicle) detects the “killed” signal, by being in the dead vehicle&#39;s line of fire, it can respond with a “claim kill” request. The dead vehicle can “grant” the kill to the requesting vehicle. If the claiming vehicle does not receive the grant signal, then it is lost. A toy vehicle is not able to accept a granted kill signal if it has not recently requested a claim. The firmware of the claiming vehicle provides for this by allowing claims to be accepted for only a limited period of time following a claim request. As the game begins, each user attempts to destroy the other users&#39; toy vehicle utilizing movement techniques and one or more simulated weapons. As the game proceeds, each player attempts to drive his vehicle over or near the tag bases in order to receive the advantages afforded by the tag bases. The tag bases may provide short time advantages such as heavy, medium or light armor, invisibility, an extra missile launcher, etc. Each player receives points based upon passing over or near tag bases, firing a simulated weapon resulting in a hit of another toy vehicle and achieving other goals. The multiplayer game can be played with teams. In addition, one or more of the droids can be used as a common adversary or to add interest in a multiple player game. Alternatively, all of the toy vehicles can play together as a team against one or more droids. 
     For example, although wireless radio control is preferred, other known forms of wireless control such as optical control might be used. The control signals might be passed over a band width spaced from the bandwidth used by the vehicle “weapons”. In such vehicles, control signals would be transmitted by an emitter and received by an appropriate optical sensor. It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. *It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.