Trinary to trinary rolling code generation method and system

• US 7,589,613 B2
• Filed: 04/03/2006
• Issued: 09/15/2009
• Est. Priority Date: 04/03/2006
• Status: Expired due to Fees

• Current Assignee: Lear Corporation
• Original Assignee: Lear Corporation
• Inventors: Kraft, Clifford H.
• Primary Examiner(s): Bugg; George
• Assistant Examiner(s): KING, CURTIS J
• Application Number:
  US11/396,964
• Publication Number:
  US 20070236328A1
• Time in Patent Office: 1,261 Days
• Field of Search: 340/2.7, 340/5.2, 340/5.7
• US Class Current: 340/5.26
• CPC Class Codes: G07C 2009/00253 dynamically, e.g. variable code - rolling code
• CPC Class Codes: G07C 2009/00769 with data transmission performed by wireless means
• CPC Class Codes: G07C 2009/00928 for garage doors
• CPC Class Codes: G07C 9/00182 operated with unidirectional data transmission between data carrier and locks

Abstract

An all-trinary rolling code method and system which allow a barrier opener to generate and transmit trinary rolling codes without entering or storing any rolling code values as binary words includes obtaining a stored trinary counter value upon a transmitter being actuated to remotely control a barrier. A trinary function void of trinary to binary or binary to trinary conversions is used to transform the trinary counter value to a trinary rolling code output such that the trinary rolling code output represents a trinary value that would be produced if the trinary counter value were converted to binary, mirrored, had its highest ordered bit set to zero after being mirrored, and converted back to trinary. The trinary rolling code output is combined with a stored trinary transmitter identification value to generate a trinary word. The transmitter transmits the trinary word for receipt by a receiver associated with the barrier.

Claims

1. A method comprising:

obtaining a trinary rolling counter value stored in a transmitter upon the transmitter being actuated to remotely control a barrier;

using a trinary function void of any trinary to binary conversions or any binary to trinary conversions to transform the trinary rolling counter value to a trinary code output such that the trinary code output represents a trinary value that would be produced if the trinary rolling counter value were converted to binary, mirrored, had its highest ordered bit set to zero after being mirrored, and converted back to trinary;

combining the trinary code output with a trinary identification value stored in the transmitter to generate a trinary word, wherein the trinary identification value identifies the transmitter; and

transmitting the trinary word from the transmitter for receipt by a receiver associated with the barrier.

2. The method of claim 1 further comprising:

adding a fixed value to the trinary rolling counter value to generate a new trinary rolling counter value; and

storing the new trinary rolling counter value in the transmitter for the new trinary rolling counter value to be obtained upon the transmitter being subsequently being actuated to remotely control the barrier.

3. The method of claim 1 wherein:

the trinary function determines a power series of two that converges to the trinary rolling counter value, wherein the determined power series is represented by a set of power series coefficients.

4. The method of claim 3 further comprising:

permuting the set of power series coefficients to produce a new power series.

5. The method of claim 4 wherein:

permuting includes mirroring the power series coefficients about a predetermined point in the power series.

6. The method of claim 3 wherein:

the trinary function successively reduces the trinary rolling counter value by decreasing powers of two using trinary arithmetic to form the new power series.

7. The method of claim 6 wherein:

the decreasing powers of two are stored in a table which is stored in the transmitter.

8. The method of claim 4 wherein:

permuting the power series includes adding permuted powers of two into a running sum using trinary arithmetic to produce the trinary code output.

9. The method of claim 8 wherein:

the permuted powers of two are stored in a table which is stored in the transmitter.

10. A system comprising:

a transmitter;

a user activation input;

a memory for storing a trinary rolling counter value and a trinary identification value, wherein the trinary identification value identifies the transmitter;

a processor in communication with the user activation input and the memory, wherein the processor;

(a) retrieves the trinary rolling counter value from the memory based on receiving a signal from the user activation input;

(b) transforms the trinary rolling counter value to a trinary code output by performing a sequence of trinary operations void of any trinary to binary conversions or any binary to trinary conversions on the trinary rolling counter value;

(c) interleaves the trinary code output and the trinary identification value to generate a trinary word; and

(d) transmits the trinary word using the transmitter for receipt by a receiver;

wherein the processor transforms the trinary rolling counter value to the trinary code output by;

(i) initializing the trinary code output to zero;

(ii) initializing an index (I) to N−

1, where N is an integer representing the length of the trinary rolling counter value;

(iii) comparing the trinary rolling counter value to 2^I;

(iv) if the trinary rolling counter value is greater than 2^I, then subtracting in trinary 2^I from the trinary rolling counter value and adding in trinary 2^(N−

I−

1) to the trinary code output;

(v) decrementing I by 1; and

(vi) repeating steps (iii) to (v) until I equals zero.

11. The system of claim 10 wherein:

the processor further

(e) adds a fixed value to the trinary rolling counter value to generate a new trinary rolling counter value; and

(f) stores the new trinary rolling counter value in the memory for the new trinary rolling counter value to be retrieved by the processor upon the processor receiving a subsequent signal from the user activation input.

12. The system of claim 10 further comprising:

a table stored in the memory and accessible by the processor, the table containing trinary values of 2^I for each value of I from 0 to N−

1.

13. The system of claim 10 further comprising:

a table stored in the memory and accessible by the processor, the table containing trinary values of 2^(N−

I−

1) for each value of I from 0 to N−

1.

14. The system of claim 10 further comprising:

a table of two columns and N rows stored in the memory and accessible by the processor, each row of the table representing a value of I from 0 to N−

1, the first column containing trinary values of 2^I and the second column containing trinary values of (N−

I−

1).

15. The system of claim 10 wherein:

the transmitter comprises an oscillator generating a radio frequency (RF) carrier signal, and a modulator in communication with the processor, wherein the modulator modulates the RF carrier with the trinary word.

16. The system of claim 15 wherein:

the modulator is a pulse width modulator.

17. A remote control system for remotely controlling a garage door responsive to a radio frequency (RF) signal modulated by a trinary code output, the remote control comprising:

an oscillator for generating a RF carrier signal;

a modulator for modulating the RF carrier signal with a modulation signal;

a user activation input;

a memory for storing a previous trinary rolling counter value;

control logic in communication with the modulator, the user activation input, and the memory, wherein the control logic in response to receiving an activation signal from the user activation input;

(a) retrieves the previous trinary rolling counter value from the memory;

(b) adds, in trinary, a fixed value to the previous trinary rolling counter value to produce a new trinary rolling counter value;

(c) stores a copy of the new trinary rolling counter value as the previous trinary rolling counter value in the memory;

(d) performs, in trinary, a binary mirror operation, on the new trinary rolling counter value to produce a trinary code output;

(e) generates the modulation signal based on the trinary code output; and

(f) transmits the RF signal to control the garage door.