Communication system for radio controlled toy vehicle

• US 20020106967A1
• Filed: 01/14/2002
• Published: 08/08/2002
• Est. Priority Date: 02/08/2001
• Status: Active Grant

• Current Assignee: Mattel Incorporated
• Original Assignee: Mattel Incorporated
• Inventors: Weiss, Stephen NIcholas, McCall, Charles Stewart, White, Wallace
• Granted Patent: US 6,848,968 B2
• Time in Patent Office: Days
• US Class Current: 446/454
• CPC Class Codes: A63H 30/04 using wireless transmission
• CPC Class Codes: H04L 1/0063 Single parity check
• CPC Class Codes: H04L 25/4904 using self-synchronising codes, e.g. split-phase codes
• CPC Class Codes: H04L 7/0331 with a digital phase-locked loop [PLL] processing binary samples, e.g. add/subtract logic for correction of receiver clock H04L7/0337 takes precedence

Abstract

A communication scheme is employed for transmitting control signals from a remote control to a toy vehicle. The remote control includes control switches, an encoder and a transmitter and the toy vehicle includes a receiver, a decoder and actuators for controlling the operation of the toy vehicle in accordance with received control signals. The encoder generates a continuous stream of control signal packets with each of the packets including a predetermined number of biphase encoded bits. Each biphase encoded bit is of the same predetermined width with a 50% duty cycle, including two transmit elements. For one binary state, both of the transmit elements are the same and for the other binary state both of the transmit elements are opposite. Each packet includes a first predetermined number of flag bits, a second predetermined number of data bits and at least one checksum bit.

Claims

1. In a communication system for transmitting control signals from a remote control to a toy vehicle, the remote control including control switches, an encoder and a transmitter, the toy vehicle including a receiver, a decoder and actuators for controlling the operation of the toy vehicle in accordance with control signals received from the remote control, wherein the improvement comprises:

the encoder generating a continuous stream of control signal packets, each of the packets including a predetermined number of biphase encoded bits, each biphase bit being of the same predetermined width with a fifty percent duty cycle including two transmit elements with one binary state being defined as both of the transmit elements of a bit being the same and the other binary state being defined as both of the transmit elements of a bit being opposite, each packet including a first predetermined number of flag bits which are the same for all packets, a second predetermined number of data bits which vary depending upon the positions of the control switches and at least one checksum bit.

2. The communication system as recited in claim 1 wherein a binary “

zero”

is defined as both transmit elements of a bit being the same and a binary “

one”

is defined as both transmit elements of a bit being opposite.

3. The communication system as recited in claim 1 wherein each packet includes sixteen bits.

4. The communication system as recited in claim 3 wherein the first predetermined number of flag bits is six.

5. The communication system as recited in claim 4 wherein the second predetermined number of data bits is eight.

6. The communication system as recited in claim 5 wherein three of the data bits are for controlling the drive functions of the toy vehicle and three of the data bits are for controlling the steering functions of the toy vehicle.

7. The communication system as recited in claim 6 wherein two of the data bits are for controlling additional toy vehicle functions.

8. The communication system as recited in claim 1 wherein the packet include two checksum bits determined by adding together all of the ones in the data bits and using the lower two bits of the sum.

9. The communication system as recited in claim 1 wherein the flag bits are at the leading edge of each packet and are followed by the checksum bit(s) and the data bits.

10. The communication system as recited in claim 1 wherein the decoder reads the received control signals at the middle of each transmit element of each bit within the packet.

11. The communication system as recited in claim 10 wherein the decoder comprises a microprocessor.

12. The communication system as recited in claim 1 wherein the receiver includes a digital phase-locked loop for synchronization of the decoder with the received stream of packets.