US20030148703A1

US20030148703A1 - Systems and methods for radio control and operation of a miniature toy vehicle including interchangeable bodies

Info

Publication number: US20030148703A1
Application number: US10/137,858
Authority: US
Inventors: Ken Scott; Ron Clements; David Berkowitz; John Montgomery
Original assignee: XXAP DESIGN Inc
Current assignee: XXAP DESIGN Inc
Priority date: 2001-05-03
Filing date: 2002-05-01
Publication date: 2003-08-07
Also published as: WO2002089939A2; AU2002256430A1; WO2002089939A3

Abstract

A radio control system for a single or multi-controller, single or multi-receiver independently controlled system providing digital and proportional control without mutual interference, especially suited for a miniature toy vehicle. The controller may operate on multiple frequencies (channels) selected by the user. The receivers may receive on multiple frequencies (channels) selected by the user. When the receiver is first turned on, it reads the channel select switch and sets its receiver accordingly then normal remote control signals may be received such as speed, steering and digital commands. Commands are sent in bursts with an error checking protocol implemented. Commands are not executed by the receiver unless they are received error free. If the receiver fails to receive error-free command bursts within a short period of time (less than one second), it shuts off all motors and controls and go into a dormant state awaiting an error-free command burst. If error-free command bursts are not received within an extended period of time such as two minutes, the receiver completely shuts off thereby conserving battery power. The receiver includes a long-life rechargeable battery system that lasts for the normal lifetime of the car. The vehicle includes a simplified steering system that provides full proportional control without requiring position feedback.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No. 60/288,684 (Attorney Docket No. 020864-000300US) filed May 3, 2001 which is herein incorporated by reference for all purposes.[0001]

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a radio control system in which a plurality of receivers are independently controlled by a plurality of radio controllers without mutual interference, and a toy vehicle including the same.

2. Description of the Prior Art

Radio control systems are well known for many applications including toys such as, for example, toy cars, toy boats and toy airplanes. However, such systems are usually large, complex and require the user to change components to set the operating frequencies so that they do not mutually interfere with each other.

Existing small products have tried to imitate typical/normal use of a vehicle. They were only successful in providing part of the experience but could not provide a completely self contained and independently controlled vehicle. For example, there are vehicles that receive their energy source from outside the vehicle, or that can be steered by external sources such as slot cars.

There are existing remote control cars that have full digital proportional control of both speed and steering giving variable movement left/right and forward/reverse. They are primarily meant for outdoor use as they are large and fast. They generally do not work well in confined or limited spaces.

There are also a number of vehicles meant for use indoors. They range from vehicles with limited control of two or three functions, to vehicles with limited features. There is also a type of miniature car for indoor use by racing on a track but it contains only a motor. Previous inventions were unable to provide the means to realistically control a vehicle. These cars run on a track with a slot to control the steering and metal guides to transfer power to the motor. There was also a wire to connect the controller to the track or vehicle. In a racing environment, current playsets allow only two slot cars running on a track with each vehicle coupled to a groove and power strip in the track. There is no means to operate the vehicles independently of the groove in a track. Furthermore, alternative existing systems designed for large vehicles, require use of matching crystal sets to be plugged into the transmitter and receiver to allow more than one to operate simultaneously in a given area.

Existing remote controlled vehicles which have internal power sources have used non-rechargeable batteries that required frequent replacement or rechargeable batteries that were large, had a limited life span and required frequent recharging.

There is a very large installed base of miniature cars, track and play sets. To increase the users enjoyment of these accessories, there is a need for an indoor vehicle with variable controls that can work on or independently of a track or a play set. The problem that until now has not been overcome is to make a vehicle for confined spaces that is completely controllable and can be used independently or with any track, play set, or racing environment.

Thus, a miniature vehicle with proportional control of the steering and speed has not been successfully designed. Attempts have been made over the years to design a controllable vehicle that works with existing miniature vehicle play sets. A variety of methods to accomplish parts of this have been developed and include:

Make a slot in a track to control the steering and power the motor through two external contacts;

Use a solenoid to force the steering left and right. This provides only limited control since it is not proportional;

Install a capacitor to charge and provide power to a motor to drive the wheels. This type does not allow proportional speed and has no steering function;

Connect the car to a spring loaded or motor driven external device that projects the car forward;

Use a spring to wind up and drive the rear wheels; and

Drive some of the vehicles on a track with vertical sides.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a control system for radio controlled devices which overcomes the limitations of the prior art.

More specifically, it is an object of the present invention to provide a control system for a radio controlled device that permits the proportional and digital control of many functions for a plurality of systems without mutual interference between them.

Still another object of the present invention is to provide a simplified method for the users to set up the system in a multiple transmitter and receiver environment.

A still further object of the present invention is to enable the receiving device to be miniaturized in both size and weight.

According to an aspect of the present invention, there is provided a radio control system of the type having a plurality of receivers that are independently radio controlled by a plurality of radio controllers comprising the ability in each controller to repetitively generate command bursts.

According to a feature of the present invention, the command burst sent by a controller is encoded in such a way as to contain error control information without excessive overhead such that the receiver may easily check the integrity of the received burst and reject any bursts that are not entirely error free.

According to a further feature of the present invention, the receiver shuts off any motors or other operations if it fails to receive an error free command burst within a specific time period.

According to a further feature of the present invention, the controller normalizes the analog (proportional) control signals to zero such that when the transmitter is first turned on, the analog inputs such as, for example, steering or speed, that are assumed to be in their zero position, are sent as a zero command.

According to yet a further feature of the present invention, a radio controlled toy vehicle comprises at least one front wheel, at least one rear wheel, a motor coupled to at least one of the wheels, a receiver including a channel selecter, an antenna coupled to the receiver and a steering drive apparatus coupled to the at least one front wheel, the steering drive apparatus comprising a stepper motor.

In accordance with another feature of the present invention, the vehicle further comprises dust cones coupled to each wheel.

In accordance with yet another feature of the present invention, the antenna comprises a substantially flat metallic strip.

In accordance with another feature of the present invention, a standard chassis of each vehicle type (including but not limited to) such as Racer, Sedan, Sports car, SUV, Truck, Van, Tank, F 1 etc. is utilized, and thus allows multiple styles of color, appearance, versions, brands, banners on vehicle bodies to be attached to the chassis.

The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings in which like reference numerals designate the same elements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a radio controlled toy automobile system in accordance with the present invention; [0031]
FIG. 2 is a schematic illustration of the receiver system illustrated in FIG. 1; [0032]
FIG. 3 is a schematic illustration of the transmitter system illustrated in FIG. 1;. [0033]
FIG. 4 is an exploded perspective of a toy automobile in accordance with the present invention; [0034]
FIG. 5 is a schematic illustration of a toy automobile in accordance with the present invention illustrating an example of a dust cone and a portion of an antenna; [0035]
FIG. 6 is a schematic illustration of a toy automobile in accordance with the present invention further illustrating the antenna example of FIG. 5; and [0036]
FIG. 7 is a schematic illustration of a toy automobile in accordance with the present invention further illustrating the dust cone.[0037]

DESCRIPTION OF SPECIFIC EXEMPLARY EMBODIMENTS

Referring now to FIGS. [0038] 1-3, a radio controlled toy automobile system 10 is illustrated and includes a plurality of control sets x-1 to x-N that may be simultaneously energized to transmit command signals to a plurality of toy automobiles 1 to N. Each control set, for example, controller 1, includes a transmitter 11, a channel select code generator 12 providing a selectable channel code, such as for example, any one of channels 1-N to transmitter 11, a speed command generator 13 and a steering command generator 14. Transmitter 11 repetitively transmits bursts of command signals containing channel, speed, steering and control data on antenna 15 that are received only by the automobile tuned to the particular corresponding transmitter channel. Note, for simplicity and clarity, the present invention is being described with reference to a toy automobile. Those skilled in the art will understand that many features of the present invention are applicable to other devices and systems. Power is preferably provided by a battery 16.
Furthermore, the present invention is generally directed to, and makes possible, radio controlled miniature toy vehicles that are typically {fraction (1/58)}-{fraction (1/62)} in scale or smaller. In real terms, this works out to vehicles that are generally 3″ long or smaller when the toy vehicle is an automobile, truck, etc. [0039]
Each toy automobile, for example, toy automobile x-[0040] 1, contains a receiver 20 that is tuned to the respective transmitter channel by means of a selector switch 21 and receives a signal from an antenna 22, and that in turn feeds the demodulated signals to a command decoder 23. When a command burst received in the receiver and applied to the command decoder is correct, the command decoder stores the steering, speed and control signals and begins producing: a) steering pulses for the steering motor that is coupled to a steering apparatus 24; b) a pulse width modulated drive signal that is applied to a drive motor 25; and c) digital control signals that may operate devices such as lights, horns, etc. (Not shown). Power is preferably provided by a battery 26.
In FIG. 4, [0041] selector switch 21 is illustrated as a switch or button on the receiver printed circuit board. In an alternative embodiment, a push button is provided with an LED on the bottom of the vehicle. The default channel is one. To change the channel, the push button is depressed a corresponding number of times for a desired channel. The LED flashes the corresponding number of times.
Preferably, proportional steering is accomplished by means of a [0042] stepper motor 27 included with the toy vehicle. This permits precise control of the steering mechanism with a low power requirement, which could be by means of a worm gear turning other gears or a spur gear turning other gears and/or the addition of a steering rack. Preferably, the wheel hubs are an integral part of the mechanism to help keep it simple and small.
The steering signal fed from the command decoder to a [0043] steering drive apparatus 28 is converted to a 2-phase stepper motor drive signal. When the vehicle is first turned on, it centers its steering by driving the steering to one end of its travel then returning a preset number of stepper motor steps. Steering commands are then executed to turn the vehicle right or left by sending the appropriate number of pulses to the stepper motor. The controller keeps track of the position of the steering mechanism by storing the pulse count. Such a control system which responds directly to commands is known as an “open-loop” control system.
The speed signal fed from the command decoder to the drive apparatus is converted to a pulse-width modulated signal, which is applied to a direct current motor and determines the speed at which the toy vehicle is driven. It may be seen in FIG. 1 that no feedback line is provided from drive apparatus to the command decoder. Such a control system which responds directly to commands is known as an “open-loop” control system. [0044]
The command decoder preferably responds only to a command burst which is correct in every respect. Command bursts received with any errors are preferably rejected by the command decoder that continues to execute the last properly decoded command burst it received. Preferably, an entire set of channel, speed command, steering command and control signals is transmitted in a command burst. As previously noted, the command decoders preferably reject all command bursts that are not correct in every respect. Preferably, the command decoder stores, and continues to execute, the last properly decoded command signals until the next properly decoded command burst occurs. Thus, when interference causes rejection of one or two command bursts, execution of the most recent command continues for one or more additional periods until the next properly decodable signal is received. By making the burst repetition frequency high enough, the loss of one or a few consecutive command bursts has little or no noticeable effect on the performance of the controlled vehicle. [0045]
The command burst may have any format capable of transmitting the required information including time, frequency, position and width coding, but in a preferred embodiment, digital coding sent and received by a standard UART (Universal Asynchronous Receiver/Transmitter) in NRZ format is employed. Preferably, seven bytes are sent in each command burst. Obviously, more or less bits may be sent as needed or desired. The first byte, called the preamble, is used by the receiver demodulator to set the slicing level and as an indication that this is the first byte in the burst. This byte has a unique value that never occurs in any other byte. The next byte is the channel number and is used only to verify that the receiver is set to the same channel as the transmitter. Only eight channels are allowed and are encoded in the four least significant bits (low nibble) of the byte. The four most significant bits (high nibble) are set to the compliment of the least significant bits and is used for error detection by the receiver as well as maintaining the slicing level for the demodulator. The speed command which is an eight bit value is encoded into the next two command burst bytes. The first byte contains the low nibble of the speed command in its low nibble and the compliment of it in the high nibble. The second byte contains the high nibble of the speed command in its low nibble and the compliment of it in the high nibble. As with the channel byte, this system is used for error detection by the receiver as well as maintaining the slicing level for the demodulator. The steering command, which is preferably an eight bit value, is encoded into the next two command burst bytes in a similar manner to the speed command. The last byte is the control command and is used to control functions such as lights or a horn on the vehicle. Only four bits are used and are encoded in the four least significant bits (low nibble) of the byte. The four most significant bits (high nibble) are set to the compliment of the least significant bits as with the previous command bytes. [0046]
The table below shows the equivalent decimal ranges available for the channel code, speed command, steering command and control command signals. [0047]

NUMBER NOMINAL DECIMAL RANGE

COMMAND OF BYTES MINIMUM CENTER MAXIMUM

PREAMBLE

1 85 85 85

CHANNEL 1 0 N/A 7

SPEED 2 0 128 254

STEERING 2 0 128 254

CONTROL 1 0 N/A 15
The 8-bit speed command signal has 254 possible decimal values, the nominal range employed is from 0 (maximum reverse speed) through 127 (stopped) to 254 (maximum forward speed). The 8-bit steering command signal has 254 possible decimal values, the nominal range employed is from 0 (full left) through 127 (straight ahead) to 254 (full right). An automatic bias correction is generated in the command encoder to produce operation centered on decimal numeral 128. More channels may be included depending upon the requirements and the design. [0048]
A speed command generator preferably comprises a manually controllable speed variable resistor between a voltage supply +V and ground with the wiper an input of a speed A/D converter input to the processor. Similarly, the steering command generator includes a manually controllable steering variable resistor connected between a voltage supply +V and ground with the wiper an input of a speed A/D converter input to processor. [0049]
The channel select switch is optionally an octal rotary switch connected to inputs of the transmitter controller. Any octal number from 0 may be applied to the transmitter controller. Other techniques for providing a channel select code to transmitter controller should be considered within the scope of the present invention. [0050]
The controller preferably sends a seven byte command burst approximately every 15 milliseconds. The command bursts are generated by the microcontroller and coupled to the transmitter IC. The transmitter IC then generates a frequency modulated, radio frequency signal and transmits this signal via antenna. Other forms of modulation may be considered within the scope of the present invention. [0051]
When the controller is first turned on, the microcontroller reads the channel select switch and sends control signals to the transmitter to set its frequency to the selected channel. The microcontroller then reads the analog inputs for speed and steering, converts their respective inputs to an eight bit digital byte then applies an offset to them that when added to the digital value converts that digital value to a decimal value of 128. It is assumed that when the transmitter is first turned on, the speed and steering controls are in their neutral position; in other words motion stopped and steering straight ahead. [0052]
When the receiver is first turned on, the microcontroller tunes the RF receiver IC to the channel selected by the user. The receiver is now ready to receive command bursts from the controller. A timer is also preferably implemented such that if no acceptable signal is received within a preset period of time, the receiver turns off all of its power, thus conserving battery life. [0053]
The user selects a desired channel on the receiver and transmitter before turning on their respective power switches. Preferably, there are eight channels and thus, the user selects any channel between 0 and 7. [0054]
Once the receiver and transmitter are both turned on and set to the same channel, the system is ready for normal operation. [0055]
In a preferred embodiment, the radio system is operating in the 800 MHz to 1000 MHz band. Operation in any other frequency range may be considered within the scope of the present invention. [0056]
Referring now to the vehicle system shown in FIG. 1, command bursts received from a transmitter are coupled from the antenna to the receiver which was previously set to the transmitter channel during startup. [0057]
The steering signal fed from the command decoder to the steering drive apparatus is converted to a 2-phase stepper motor drive signal. The steering stepper motor applies mechanical force to control the angle to which steering wheels, not shown, are turned to deflect them toward the left or the right. When the vehicle is first turned on, it centers its steering by driving the steering to one end of its travel then returning a preset number of stepper motor steps. Steering commands are then executed to turn the vehicle right or left by sending the appropriate number of pulses to the stepper motor. The controller keeps track of the position of the steering mechanism by storing the pulse count. [0058]
A pulse width modulated speed signal is applied from the command decoder to a speed control circuit. The pulse width modulated speed signal is applied to a speed drive circuit which, in turn, applies the pulse width modulated speed signals to a speed drive motor. The speed drive motor produces either a forward torque, a rearward torque according to the input from the speed drive circuit. It should be noted that there is no signal fed back to the command decoder representative of the speed at which the drive wheels are rotated. [0059]
If a vehicle fails to receive an error free command burst in a predetermined period of time, suitably from about 0.1 to about 0.3 seconds, the command decoder stops the drive motor. This avoids the toy vehicle running away and becoming lost or damaged when the control signal is lost due to distance, malfunction or turning off the control set. [0060]
In a preferred embodiment, the power from the rechargeable battery is split into two sources. The first source (Vbat) is used for logic control and the second source (Vbat-P) is used for drive and steering. Partitioning of the power sources in this way permits relatively tight regulation of the DC power employed in logic control without placing unnecessary limitations on the relatively high current power sources required by the steering motor and the speed drive motor. Thus, the drive systems are capable of operating with an unregulated battery source that may be isolated from the regulated logic DC source. [0061]
Preferably, a battery fabricated with a technology that allows it to be made very thin is used. Preferably, it is designed in some degree to fit the shape of the vehicle. In an alternative embodiment, the battery is an integral part of the mechanical construction of the car. By designing the battery to the desired shape of the product, one may optimize the energy capacity and no longer be hindered by its conventional shape. The product may be designed as required and the battery shaped to be an integral part of the design. [0062]
Preferably, as may be seen in FIG. 4, each vehicle has a [0063] removable body 30. Thus, various chassis 31 have several common bodies. For example, NASCAR shaped cars are quite similar in chassis although there are a few brands and many advertisers/drivers. By making removable bodies, people may retain their existing chassis (and their investment in the mechanical/electrical portion of the vehicle) and change bodies based on their favorite drivers and advertisers each year. Another example is an SUV chassis as well that may take various branded bodies.
With reference to FIGS. 5 and 6, an example of an [0064] antenna 40 may be seen. Typical radio controlled cars have very large and disproportionate to scale antennas. The present invention preferably uses a higher frequency signal (900 Mhz range) to reduce the need for a larger antenna. Due to the extremely small scale of vehicles in accordance with preferred embodiments of the present invention, a larger or longer antenna would look out of scale. Thus, in accordance with a preferred embodiment of the present invention, the antenna is located under the car, mounted to the bottom of chassis 31. Additionally, preferably antenna 40 comprises a metallic strip. Such a design provides better performance than just using a traditional wire antenna. Furthermore, the design doesn't detract from the appearance of the vehicle.
With reference to FIGS. 5 and 7, a [0065] dust cone 50 is illustrated. Radio controlled vehicles often pick up lint and carpet fibers etc., that wrap around the axles, tighten up and usually cause the vehicles to run slower or even stop. The dust cone is preferably in the form of a “lint ring” that extends from the chassis into an inner portion 51 of wheel hubs 52.
Thus, the present invention provides a miniature remote control vehicle with variable control that operates independently by means of wireless operation. Advantages include: [0066]
1) Uses a high frequency thus reducing the size of antenna to maintain proportionality of scale; [0067]
2) Controlled with variable steering preferably using a stepper motor (Alternative methods include servo or sensors combined with new motor design or shape, such as piezo, or two coils (motors) connected together like a stepper motor); [0068]
3) Battery designed to the required shape of the vehicle. (Use of a battery as an integral part of the design of the product, i.e. making the vehicle where the form/shape of the battery is made to a structural part of the design, such as making the battery the shape of the vehicle chassis. This allows maximizing the energy capacity and making the vehicle smaller/thinner/lighter); [0069]
4) Additional functions besides variable speed and steering permitted through coding design. (for example light and sound); [0070]
5) Uses internal frequency calculation and channel selector switch to permit simultaneous operation of multiple vehicles; and [0071]
6) Small size allows car to be used in conjunction with large base of existing miniature tracks and play sets. [0072]

Following are examples of receiver and transmitter operation in outline form:



RECEIVER OPERATION

1.	General initialization

	a.	Initialize I/O ports
	b.	Initialize variables
	c.	Turn on 2.8 V to RF section
	d.	Initialize pulse-width-modulator for speed control
	e.	Initialize A/D converter for battery voltage checking (AN3)
		and steering-centering pulse count value (AN0)
	f.	Initialize software serial port for receive
	g.	Read address switch
	h.	Initialize frequency synthesizer per address switch setting
	i.	Get steering centering step count (AN0)
	j.	Center steering
	k.	Initialize and start no-data-timer
	l.	Wait for good data packet
	m.	Center steering again (an indication that good data is being
		received)

2.

Main loop

a.

Perform no-data test

	i.	If no good-data packets received in ¼ second,
		shut off motors and control outputs

b.

Execute steering control commands

	i.	Convert steering command to number of steps for
		stepper motor. To prevent wheels from going to
		end stops (either left or right), scale steering
		input such that wheels turn only a fixed
		percentage of maximum (presently 88%)
	ii.	Test if steering command has changed by at least
		2 counts

	1.	If not, do nothing
	2.	If changed, get value of change and
		move stepper motor in appropriate
		direction

c.

Execute speed control commands

	i.	If speed command too small (less than 4) assume
		zero speed and stop motor and perform battery
		voltage check
	ii.	If speed command greater than 4, test for
		direction (forward or backward) and set pulse-
		width-modulator and direction control (PC7) as
		required to run motor

d.

Execute digital control commands

	i.	Set control outputs PA4 or PB4 as requested by
		control byte

	e.	Check battery voltage and shut-down vehicle when battery
		voltage is too low to provide reliable operation.

3.	Interrupt functions (background tasks)

a.

Check UART for received data and if available:

	i.	Assemble received data into complete packet and
		check for integrity
	ii.	If data packet check OK, set new speed, steering
		and control bytes for use in main loop
	iii.	If data packet bad, reject all data and do not
		change speed, steering and control bytes used in
		main loop

b.

Timer interrupt used for no-activity timer

	i.	No-activity timer reset when good data packet is
		received.
	ii.	On no-activity timeout, turned off power to the
		RF chip, shut off motors and control outputs, set
		the processor I/O for lowest current drain and put
		processor into sleep mode

TRANSMITTER OPERATION

1.	General initialization

	a.	Initialize I/O ports
	b.	Initialize variables
	c.	Initialize software serial port
	d.	Initialize timer 1 for use as no-activity timer
	e.	Set up interrupts
	f.	Initialize A/D converter
	g.	Read address switch
	h.	Initialize the frequency synthesizer
	i.	Read the controller potentiometer center settings
	j.	Normalize potentiometer settings to 80 h
	k.	Enable global interrupts

2.

Main loop

	a.	Read potentiometer (steering and speed) inputs and
		reset no-activity timer if potentiometers have been moved.
		Limit speed and steering outputs to 0 and FEh
	b.	Check battery voltage

	i.	Provide indication to user of low battery.
	ii.	Shut off transmitter when battery voltage is too
		low for reliable operation.

c.

Send data packet

	i.	Send preamble byte (55 h)
	ii.	Send address switch setting as one byte
	iii.	Send speed setting as two bytes
	iv.	Send steering setting as two bytes
	v.	Read and send control bits as one byte

3.	Interrupt functions (background tasks)

	a.	UART interrupt to send data.
	b.	Timer interrupt used for no-activity timer

	i.	No-activity timer reset when potentiometer
		movement is detected.
	ii.	On no-activity timeout, power is turned off to the
		RF chip and the processor I/O is set for lowest
		current consumption and processor is placed into
		sleep mode

Having described specific preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims. [0074]

Claims

What is claimed is:

1. A radio control system comprising at least one control set to transmit command signals for operation of a remotely controlled device, the controlled device comprising a receiver to receive the transmitted control signals and a decoder to decode the control signals and act upon the control signals as required either sequentially or concurrently.

2. A radio control system in accordance with claim 1 wherein the radio control system comprises a plurality of controlled devices, each controlled device being independently controlled by a respective receiver such that the receivers do not interfere with each other.

3. A radio control system in accordance with claim 1, wherein command bursts are transmitted by the at least one control set encoded such that the receiver may detect errors in the received data burst and thereby reject erroneous data.

4. A radio control system in accordance with claim 2, wherein command bursts are transmitted by the at least one control set encoded such that the corresponding receiver may detect errors in the received data burst and thereby reject erroneous data.

5. An apparatus for communicating between a plurality of controllers and a plurality of receivers in a radio control system wherein said plurality of receivers are independently controlled by said plurality of controllers, respectively, said apparatus comprising:

means in each of said plurality of controllers for generating a radio frequency signal;

said controller including means for a user to set the frequency of operation;

said controller including means of modulating the radio frequency signal;

a receiver in each of said plurality of receivers for receiving said radio frequency signal;

said receiver including means for demodulating said radio frequency signal; and

means of error control to prevent erroneous response to noise or interference.

6. A radio control system in accordance with claim 1 wherein the controlled devices comprise a toy vehicle.

7. A radio controlled toy vehicle comprising:

at least one front wheel;

at least one rear wheel;

a motor coupled to at least one of the wheels;

a receiver including a channel selecter;

an antenna coupled to the receiver; and

a steering drive apparatus coupled to the at least one front wheel, the steering drive apparatus comprising a stepper motor.

8. A radio controlled vehicle in accordance with claim 7 further comprising at least two bodies that may be individually coupled to a chassis of the vehicle.

9. A radio controlled vehicle in accordance with claim 7 further comprising dust cones coupled to each wheel.

10. A radio controlled vehicle in accordance with claim 7 wherein the antenna comprises a substantially flat metallic strip.