MXPA00000428A - Touchtone electronic steering wheel - Google Patents

Abstract

A steering wheel control system (10) that employs a method for passing push-button commands from a steering wheel to a vehicle system where the method is not dependant upon the contact resistance of a sliding contact (32) located in the steering wheel column. The control system (10) uses a steering wheel electronics assembly (20) to generate tones corresponding to the commands, a signal transmission assembly (30) to transmit the tones from the electronics assembly (20) to an electronic control box (40) located elsewhere in the vehicle, and the electronic control box (40) to decode the transmitted tone. The use of discrete frequencies avoids operational problems associated with decreases in the overall system noise margin due to large voltage drops across the sliding contact (32). Furthermore, the use of off-the-shelf tone generation and decoding components allows for an overall reduction in system cost and increase in system reliability.

Description

STEERING ELECTRONIC STEERING WHEEL CROSS REFERENCE TO THE RELATED APPLICATION This application is related to the commonly assigned application entitled: "Electronic Steering Wheel Technique for Passing Information with a Programmable Current Source and Detector", (Electronic Steering Wheel Technology for Passing Information with a Programmable Current Source and a Detector), TRW No. of Agent 20-0080, whose inventor is Stuart G. Downs, filed on the same date of this request. This application is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to steering steering of a vehicle. More particularly, the present invention relates to an improved technique that employs distinctive tones for passing electronic information between an electronic steering wheel assembly and a vehicle system. 2. - Discussion of the Related Technique In the automotive industry, steering wheels commonly provide drivers with a number of automotive controls such as crossover control, braking, flash headlights, and flash taillights that are operated through electronic compression buttons located on the steering wheel of the vehicle These compression buttons generate electronic information that will be used by the vehicle when performing the various automotive functions Current techniques pass electronic information from an electronic assembly of steering wheel to a box Electronic control, located below the dashboard or anywhere on the vehicle The electronic steering wheel assembly is usually located in the center of the steering wheel and can have the various electronic compression buttons and lights mounted on it to operate these systems The rotary movement of the steering wheel in relation to the steering wheel column typically requires the placement of one or more sliding contacts in the column in order to pass electronic information of the steering wheel to the steering box. electronic control Typically, the electronic steering wheel assembly uses a sequence of information time bit and a signal magnitude to transport to the electronic control box which particular button has been compressed. In turn the electronic control box decodes the information electronics and activates the appropriate automotive circuit inside the vehicle This circuit technique is quite complex and difficult to maintain particularly due to the siting sequencing algorithms and the required circuit system. Another important problem with this circuit technique for transmitting signals from a vehicle steering wheel to a vehicle system has to do with the contact resistance of the sliding contacts. The sliding elements of the sliding contacts are typically spring loaded and are very prone to oxidation and other causes of surface degradation. If the electrical resistance between the sliding elements of a contact is too great, there will be an increased voltage drop across the sliding elements, which reduces the total noise margin of the system. The result is that the electronic control box can not effectively interpret the signal magnitude, and the system will both fail to operate and operate intermittently. This failure to operate properly is a source of great frustration for the driver, reduces the reliability of the system, and causes numerous repairs and very expensive. In this way, there is a need to combat the problem created by high contact resistance of the sliding contacts without increasing the cost of the entire operation of the system.

COMPENDIUM OF THE INVENTION The steering wheel control system of the present invention utilizes a high impedance AC circuit to pass electronic information between a steering wheel compression button and a vehicle system that does not depend on contact resistance. The system passes electronic information between the steering wheel compression button and the corresponding vehicle system generating a tone assigned to the electronic information, transmitting the tone of the steering wheel to the vehicle system through an AC signal superimposed on a DC source, and decoding the transmitted tone. A given tone corresponds to the particular button that is compressed and allows electronic information to pass through discrete frequencies instead of being a function of signal magnitudes. An electronic control box can then simply search for the presence of particular frequencies instead of the typical information time bit sequence at a minimum required magnitude. The present invention also utilizes a much simpler circuit than currently used due to the nature of off-the-shelf tone generation and decoding components. In addition, the present invention allows the continuous use of current sliding contacts. It should also be appreciated that the same principles can be applied to pass the electronic information from the vehicle systems to the steering wheel. Other objects, aspects, and advantages of the invention will be apparent upon consideration of the following description and the appended claims taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a functional schematic block diagram of a steering wheel control system of the present invention DETAILED DESCRIPTION OF THE PREFERRED MODALITIES The following discussion of the preferred embodiments is directed to an electronic steering wheel assembly that generates a tone indicative of a vehicle function and is merely illustrative in nature, and is not intended in any way to limit the invention or its applications or uses. Returning now to Figure 1, a steering wheel control system as generally indicated at 10, according to the invention, includes an electronic steering wheel assembly 20, a signal transmission assembly 30 and an electronic control box 40, to pass electronic information from a steering wheel compression button assembly 50 to the corresponding electrical system within the vehicle. The compression button assembly 50 includes a plurality of electrical switches, generally compression button switches, which are used to operate various vehicle systems, such as c control systems vehicle noise, emergency flash lights, etc. The present invention aims to provide an improved technique for transmitting the electrical information of the particular compression button switch to activate the corresponding vehicle system, and is thus used for a system control of existing vehicle or contemplated in a steering wheel column of the vehicle. The electronic assembly 20 is electrically connected to the steering wheel compression button assembly 50, the signal transmission assembly 30 is electrically connected to the electronic assembly 20, the electronic control box 40 is electrically connected to the signal transmission assembly 30. and the electronic control box 40, preferably located under the instrument panel, is electrically connected to the particular vehicle system through a relay bank 60. The electronic assembly 20 includes a detection circuit 21, a matching circuit 22 and a tone generator 23. The signal transmission assembly 30 includes a steering wheel signal means 31 connected to the electronic assembly 20, a sliding contact 32 connected to the steering wheel signal means 31 and a vehicle signaling means. signal 33 connected to the sliding contact 32. The signal means 31 and 33 preferably e are standard signal cables, but may also comprise other signal means such as optical fibers. It should be noted that typically the steering wheel column will also have a power sliding contact 90, but the contact resistance is not a problem due to the increased signal strength.

Finally, the electronic control box 40 includes a tone decoder 41. During operation, the electronic assembly 20 includes a tone, which preferably is an audio signal AC corresponding to the electronic information superimposed on a DC source. The detection circuit 21 it detects the electronic information of which button was compressed in the steering wheel compression button assembly 50, the matching circuit 22 matches the electronic information with the tone, and the tone generator 23 produces the tone. For example, the electronic information can be the compression button command for acceleration during the crossing control operation The acceleration command will have a corresponding tone, which can be maintained in a table of information containing information and tone pairs for all applicable vehicle systems comparison of the electronic information with the information table Therefore, it allows the electronic assembly 20 to select the appropriate tone to generate each of the detection circuits., the matching circuit 22 and the tone generator 23 can be well-known electrical circuits that will operate in accordance with the discussion herein. The signal transmission assembly 30 then transmits the tone of the electronic assembly 20 to the selected vehicle system. The tone passes of the electronic assembly 20 through the steering wheel signal means 31, through the sliding contact 32, through the vehicle signal means 33 and towards the electronic control box 40 The electronic control box 40 decodes the transmitted tone using the tone decoder to match the tone with the electronic information The tone detector 41 can also be any well-known electric tone detector operating in accordance with the discussion of the present. Similar to the matching circuit 22, the tone decoder 41 compare the tone in a tone table containing the information and tone pairs, and select the electronic information corresponding to the tone The electronic control box 40 decodes the tone generated by the tone generator 23, and based on the decoded tone signal, activates one of the automotive relay bank 60 to activate the particular automotive system corresponding to the button of compression activated in the compression button assembly 50 Therefore, the present invention allows effective transmission of signal in cases where the sliding contact 32 has a contact resistance as high as approximately 10-50 ohms, while the methods existing ones find transmission problems above about 1 to 10 ohms. It should be understood that the invention is not limited to the exact construction illustrated and described above, but rather that several changes and modifications can be made without departing from the spirit and scope of the invention. invention as defined in the following claims

Claims (9)

1. - A method for passing electronic information between a steering wheel and a vehicle system, said method comprises the steps of: generating a tone corresponding to the electronic information; transmitting the tone of the steering wheel to a tone decoder that decodes the transmitted tone; and send the decoded tone to the vehicle system.

2. The method according to claim 1, wherein the step of generating the tone comprises the steps of: detecting the electronic information; matching the electronic information with a selected tone of a plurality of available tones; and produce the tone.

3. The method according to claim 2, wherein the matching step comprises the steps of: comparing the electronic information with a table of information containing information and tone pairs; and select the tone corresponding to the electronic information.

4. The method according to claim 1, wherein the step of transmitting the tone comprises the steps of: passing the tone of the steering wheel through a steering wheel signal means; passing the tone of the steering wheel signal means through a sliding contact; passing the tone of the sliding contact through a vehicle signal means; and passing the tone of the vehicle signal medium to the tone decoder.

5. The method according to claim 1, wherein the step of decoding the transmitted tone comprises the step of matching the tone with the electronic information.

6. The method according to claim 5, wherein the step of matching comprises: comparing the tone with a tone table containing information and tone pairs; and selecting the electronic information corresponding to the tone

7. The method according to claim 1, wherein the tone corresponds to an audio signal AC superimposed on a DC source.

8. A steering wheel control system for passing electronic information of a steering wheel to a vehicle system, said control system comprising: an electronic steering wheel assembly connected to the steering wheel to generate a corresponding tone to electronic information; a signal transmission assembly connected to the electronic steering wheel assembly for transmitting the tone from the electronic steering wheel assembly, and an electronic control box that responds to the transmitted tone of the signal transmission assembly, said control box being connected to the signal transmission assembly and to the vehicle system, said control box decoding the transmitted tone and sending the decoded tone to the vehicle system 9 - The steering wheel control system according to claim 8, wherein the electronic steering wheel assembly comprises a detection circuit to detect the electronic information of the steering wheel, a matching circuit to match the electronic information with the tone, and a tone generator to produce the tone 10 - The control system of steering wheel according to claim 8, wherein the The signal transmission assembly comprises a steering wheel signal means connected to the electronic steering wheel assembly, a sliding contact connected to the steering wheel signal means, and a vehicle signal means connected to the sliding contact and to the box. of electronic control, so that the pitch passes from the electronic steering wheel assembly through the steering wheel signal means, through the sliding contact through the vehicle signal means and makes the electronic control box 11 - The steering wheel control system according to claim 10, wherein the steering wheel signal means and the vehicle signal means comprise a signal cable 12 - The steering wheel control system according to claim 10, wherein the steering wheel signal means and the vehicle signal means comprise optical fibers 13 - The steering wheel control system according to claim 10, wherein the sliding contact has a contact resistance of between approxily 10 and 50 ohms 14 - The steering wheel control system according to claim 8, wherein the electronic control box comprises a tone decoder to h the tone with the electronic inforon 15 - The control system of steering wheel according to claim 8, wherein the tone comprises an audio signal AC superimposed on a DC source 16 - The steering wheel control system according to claim 8, wherein the electronic steering wheel assembly The address further includes an address table that includes inforon regarding a plurality of tones assigned to a plurality of e steering wheel compression buttons 17 - A steering wheel control system for operating a vehicle system, said control system comprising: an electronic steering wheel assembly that generates a tone in response to a tire compression button; selected steering wheel in a vehicle steering wheel, wherein a different tone corresponds to each of a plurality of push buttons of the steering wheel, the electronic assembly including a detection circuit to detect an electrical signal of the compression button of selected steering wheel, a hing circuit to h the electrical signal of the selected push button with the generated tone, and a tone generator to produce the tone; a signal transmission assembly connected to the electronic transmission wheel assembly for transmitting the tone generated from the electronic steering wheel assembly, the electronic steering wheel assembly including a sliding contact connected to the tone generator; and an electronic control box including a tone decoder, the tone decoder connected to the sliding contact and decoding the tone back to the electrical signal to operate the vehicle system. 18. The control system according to claim 17, wherein the sliding contact has a contact resistance of between about 10 and 50 ohms. 1

9. The control system according to claim 17, wherein the generated tone is an audio signal AC superimposed on a DC source. 20. The control system according to claim 17, wherein the electronic steering wheel assembly includes an information table that includes information regarding which tone is assigned the steering wheel compression button.