HK1188420A - Control system with solid state touch sensor for complex surface geometry - Google Patents

Description

Control system with solid state touch sensor for complex surface geometries

This application claims priority from U.S. provisional patent application No. 61/406,337, entitled "solid state touch sensor for complex surface geometries", filed on 25/10/2010, which is hereby incorporated by reference in its entirety.

Technical Field

The present invention relates to control systems for devices and apparatus, and in particular to touch-sensitive control systems for devices and apparatus.

Background

Solid state touch sensing technology, such as capacitive touch sensing, for discrete (discrete) touch pads and multi-touch screens has become widely accepted in recent years for products ranging from cell phones to large displays. The success of these techniques is a direct result of improved user interaction as experienced by the user.

One benefit of using solid state sensing technology is its virtually unlimited lifetime. Unlike mechanical alternatives that have the requisite active elements that wear out over time and repeated use, solid state touch sensing technology does not have these limitations. As such, it rarely fails and the user does not have to worry about user interface failure. Solid state touch sensors have previously been incorporated under a single fixed cover (e.g., glass or molded plastic) so that the sensitive elements inside the product are substantially unaffected by the external environment. Conversely, achieving these through traditional mechanical alternatives is very difficult and costly, although not impossible.

By combining infinite lifetime with the ability to seal the user interface, capacitive sensing provides significant benefits for products used in harsh outdoor environments. However, solid state sensors have heretofore been adopted primarily in two-dimensional planes, generally by using capacitive sensors on touch screens and touch pads. Although capacitive sensors have previously been implemented on complex surfaces, they are typically limited to a single touchpad that is a digital binary switch (digital binary switches).

However, such implementations can only provide limited information about human-machine interaction for the machine. For example, in existing systems implemented in rail vehicles, the vehicle speed controller is equipped with a capacitive sensor to detect contact of the driver's hand. If the hand is removed for a longer period of time, the track brake is activated to stop or slow the vehicle. However, a disadvantage of this system is the manner and nature of the system that can only detect contact, not contact. An inattentive or careless driver may defeat the purpose of the system by avoiding application of the brakes by simply leaning on one hand or other body part on the sensor while performing other activities.

There is a need for a system that can apply capacitive or other solid state touch sensing technology to geometrically complex surfaces so that the system can determine characteristics of user contact with the surface in addition to detecting contact only.

Disclosure of Invention

Embodiments of the present invention meet the need of the industry by providing a capacitive or other solid state touch sensing system that incorporates control elements in a geometrically complex surface, wherein the system is capable of determining characteristics of user contact with the elements. As used in this application, a "geometrically complex surface" is defined as a non-planar surface.

In one exemplary embodiment, the present invention may include a vehicle steering wheel equipped with one or more solid state sensors embedded within the steering wheel that sense not only contact by the driver's hand in a simple binary manner (binary washin), but also palm coverage, firm grip, or free-standing. If the driver holding the steering wheel releases while the vehicle is in motion, the system may warn the driver to redirect his attention to the driving task, or may automatically reduce engine power or in some cases apply the vehicle brakes.

Embodiments of the present invention may include a continuous sensing surface below or above the geometrically complex surface. The sensing surface may detect not only the binary presence of a hand or other body part, but also the contours of the hand, the tightness of the bracelet around the surface, the movement of the hand due to slipping down, and other such characteristics of human and facial contact. Implementations may include a flexible carrier on which some sensors (capacitive, infrared, thermal, etc.) are placed. The flexible carrier is designed to conform to complex surface geometries. The sensors work in conjunction or separately to capture the complex but obvious interaction of a human hand with the aforementioned surfaces. The sensor data is incorporated into a processor for analysis and the resulting interaction information is transmitted to a machine for responding to the reaction.

According to one embodiment, a control system for a device includes a control apparatus having a contact surface, a solid-state touchpad overlying at least a portion of the contact surface of the control apparatus, and a signal processor communicatively coupled with the solid-state touchpad, the signal processor programmed with an algorithm to determine at least one real-time parameter regarding contact of a user's body with the solid-state touchpad. The signal processor may be communicatively coupled with the memory, and at least one predetermined threshold parameter may be defined and stored in the memory. Further, the signal processor may be programmed to compare the at least one real-time parameter to at least one threshold parameter, and the signal processor may then transmit a signal indicating whether the at least one threshold parameter is met by the at least one real-time parameter.

In one embodiment, the solid state touch pad may be a capacitive touch pad. Further, the contact surface of the control device may be of a complex geometry. The at least one real-time parameter may be an area of the area contacted by the user on the control device, a location of the area contacted by the user on the control device, a centroid (centroid) of the area contacted by the user on the control device, a duration of the area contacted by the user on the control device, and/or an amount of movement of the area contacted by the user on the control device.

In an embodiment of the present invention, the control device may be selected from the group consisting of a joystick, a steering wheel, a control lever, and a shift lever. In an embodiment, the signal processor is programmed with an algorithm to determine a plurality of real-time parameters relating to the contact of the user's body with the solid-state touchpad. In such embodiments, the signal processor may be communicatively coupled with the memory, and a plurality of predetermined threshold parameters may be defined and stored in the memory, each predetermined threshold parameter corresponding to a separate one of the real-time parameters. Further, the signal processor may be programmed to compare each real-time parameter to a corresponding threshold parameter, and the signal processor may transmit a signal indicating whether each threshold parameter is met by its corresponding real-time parameter. In an embodiment, the control system may further comprise a device controller communicatively connected to the signal processor, the device processor being adapted to control a piece of equipment.

In other embodiments, a method of controlling a vehicle or device includes placing a solid state touch pad on at least a portion of a user interface of a control device of the vehicle or device, communicatively coupling a signal processor and the solid state touch pad, and algorithmically programming the signal processor to determine at least one real-time parameter related to contact of a body of a user with the solid state touch pad. The method may further include communicatively coupling the signal processor with a memory and storing the at least one predetermined threshold parameter in the memory. The method may further include programming the signal processor to compare the at least one real-time parameter to at least one threshold parameter and programming the signal processor to transmit a signal indicating whether the at least one threshold parameter is met by the at least one real-time parameter.

In other embodiments, the method may include programming the signal processor with an algorithm to determine a plurality of real-time parameters relating to the body of the user in contact with the solid-state touchpad. The method may further include communicatively coupling the signal processor with a memory and storing a plurality of predetermined threshold parameters in the memory, each predetermined threshold parameter corresponding to a separate one of the real-time parameters. The method may further include programming the signal processor to compare each real-time parameter to a corresponding threshold parameter, and programming the signal processor to transmit a signal indicating whether each threshold parameter is met by its corresponding real-time parameter.

Drawings

The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, in which:

FIG. 1 is an isometric cross-sectional view of a joystick in accordance with one embodiment of the present invention;

FIG. 2 is a block diagram of a control system according to one embodiment of the present invention;

FIG. 3 is a flow diagram of an exemplary process according to one embodiment of the invention;

FIG. 4 is an isometric view of the embodiment of the joystick shown in FIG. 1, depicting the contact area resulting from a user grasping the joystick;

FIG. 5 is an isometric view of the joystick shown in FIG. 5 depicting the contact area resulting from a user gripping the joystick;

FIG. 6 is an isometric view of the joystick shown in FIG. 5 depicting the contact areas caused by the user accidentally touching the joystick;

FIG. 7 is an isometric view of a steering wheel according to one embodiment of the present invention;

FIG. 8 is an isometric view of the embodiment of the steering wheel shown in FIG. 7 depicting the contact area resulting from a user gripping the steering wheel; and

FIG. 9 is an isometric view of the steering wheel embodiment shown in FIG. 7 depicting the contact areas resulting from a user holding the steering wheel, one of the areas being moved by a user's hand slippage.

While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Detailed Description

According to one embodiment of the present invention as shown in fig. 1, a control device 10 generally includes a lever 12 and a spring-loaded detent plate 14. The joystick 12 generally includes a shaft 16, a spacer 18 surrounding the shaft 16, a solid state sensing board 20, a housing 22, and an embedded signal processor 24 communicatively connected to the solid state sensing board 20. The spring-loaded detent plate 14 may be any means known in the art for maintaining the joystick 12 biased to a generally vertical and centered position, and for transmitting control signals to the machine (not shown) to which it is attached based on the directional and amount of movement of the joystick 12. Notably, the surface of the joystick 12 may have a complex outer contour, such as the illustrated cylindrical shape, or other contour that is ergonomically adaptable to the shape of the user's hand. In an exemplary embodiment of the invention, solid state sensing pad 20 may be a capacitive sensing pad capable of detecting multiple simultaneous touches.

In fig. 2, a block diagram of a control system 30 according to one embodiment of the present invention is depicted. The system 30, including the device controller 32, generally includes the control device 10 and the controlled device 34. As with the previously described joystick embodiment shown in FIG. 1, the control device 10 generally includes a solid state sensing pad 20, a signal processor 24, and may also include one or more other sensing devices 36, such as Infrared (IR) or thermal sensors. The signal processor 24 may be embedded in the control device 10 as in the embodiment shown in fig. 1, or may be located remotely from the control device 10 and may be associated with memory such as RAM, EEPROM or other electronic memory circuitry (not shown).

The device controller 32 typically includes a computer processor and any associated peripherals and is programmed with algorithms to control the controlled devices 34 and to receive and process signals from the signal processor 24. For example, the device controller 32 may be a transmission control module of a vehicle transmission (transmission), while the controlled device 34 is a transmission. In such a case, the device controller 32 is typically programmed with algorithms to control and calculate, and use the information provided by the remote sensors to control how and when to shift gears in the vehicle for optimum performance, fuel savings, and shift quality. In one embodiment of the present invention, device controller 32 may also be programmed to recognize and process signals received from signal processor 24 indicating user interaction with control device 10, as described further below.

It should be noted that device controller 32 and controlled device 34 may be any machine having an associated control processor as indicated by user input. For example, the device controller 32 may be a brake system controller of a vehicle, while the controlled device is a vehicle brake system. In other embodiments, the device controller 32 may be a motion controller for a device operated by a joystick or a joystick, or a processor for generating an instrument, message, or alarm signal to a device operator. It should also be noted that the signal processor 24 may cooperate with a variety of device controllers 32 that serve different purposes and control different devices or components of the vehicle or apparatus.

In fig. 3, a flow chart of an algorithm with which the signal processor 24 is programmed according to an exemplary embodiment of the present invention is depicted. In the depicted embodiment, the threshold parameter is defined in step 38 and may be stored in a memory associated with the signal processor 24. Such threshold parameters may include, for example, a desired footprint of user contact with solid state touch pad 20, desired location coordinates of user contact with solid state touch pad 20, a maximum allowable change in location of user contact with solid state touch pad 20, and/or a desired duration of user contact with solid state touch pad 20. It should be noted that any of these parameters may be defined individually, or any combination of these or other such parameters may be defined.

In step 40, real-time parameters of user contact with the solid-state touchpad 20 corresponding to the defined threshold parameters are determined by the signal processor 24. For the embodiments presented above, the footprint of the user in contact with the solid state touchpad 20 may be calculated as a total or separate individual areas for user contact, the coordinates and centroid of the separate areas of user contact with the solid state touchpad 20 may be determined, the change in location of the centroid of the user contact area may be determined and tracked, and/or the duration of user contact with the solid state touchpad 20 may be determined.

In steps 42 and 44, each real-time parameter determined in step 40 is compared to the corresponding threshold defined in step 38. If the defined threshold parameter is not met by the corresponding real-time determined parameter, a signal is sent by the signal controller 24 to the device controller 32 at step 46 indicating that the threshold has not been met. Alternatively, if the defined threshold parameter is reached by the corresponding real-time determined parameter, a signal is sent by the signal controller 24 to the device controller 32 at step 48 indicating that the threshold has been reached. In either case, the process returns to step 40 and repeats.

It should be noted that, alternatively or in addition to the binary signals transmitted at steps 46 and 48, the values of the real-time user contact parameters determined at step 40 may be transmitted as signals only to the device controller 32 for processing. For example, the value of the footprint of the user in contact with the solid state touchpad 20, the coordinates and centroid of the separate regions of user contact with the solid state touchpad 20, the change in location of the centroid of the user contact region, and/or the duration of user contact with the solid state touchpad 20 may be communicated to the one or more device controllers 32.

Referring now to fig. 4-6 for exemplary purposes, as the user holds the joystick 12 with a hand (not shown), a solid state sensing pad 20 is used to detect various locations where the user's hand is in contact with the joystick 12, and a signal processor may determine and calculate various parameters associated with the contact area according to methods well known in the art. For example, as shown in FIG. 4, the palm of the user's hand may contact the joystick 12 at contact area 50, while the user's index, middle, ring and small fingers may contact the joystick 12 at contact areas 52, 54, 56, 58, respectively. A single processor 24 communicatively coupled to the solid state sensing pads 20 in the joystick 12 may be used to determine or calculate the area of each of the contact regions 50, 52, 54, 56, 58. Further, the location of the centroid of each region can be calculated and presented in a coordinate system such as polar or x-y-z coordinates. Likewise, the duration of contact for each region can be determined.

As previously discussed with respect to FIG. 3, any one or more of these detected or calculated parameters may be compared to a defined threshold parameter to determine whether the threshold has been reached. For example, it may be desirable to set the threshold parameter for the purpose of avoiding accidental operation of the joystick 12. In this case, the total area of the contact regions 50, 52, 54, 56, 58 may be summed and compared to a threshold value for user contact by the signal processor 24 by holding the joystick 12 with the palm and fingers as shown in FIG. 4. When the threshold is reached, the signal processor 24 may send an indication signal to the device controller 32, and the device controller 32 may then assert a control input from the joystick 12 so that movement of the joystick away from the vertical position against the biasing force applied by the spring-loaded detent plate 14 causes a control signal to be generated to the machine controlled by the joystick 12. The signal content depends on the direction and extent to which the joystick 12 is moved. If the threshold is not reached, for example, as shown in FIG. 6, if the user only accidentally hits the joystick 12 at the contact area 60, the signal processor 24 may transmit a signal to the device controller 34 and the device controller 34 may be programmed to ignore the control signal from the joystick 12.

Further, as shown in FIG. 5, if the user grips the joystick 12 more tightly, the area of one or more of the contact regions 50, 52, 54, 56, 58 may be enlarged. In addition, when the touch panel 20 is a capacitive touch panel, the degree of capacitive coupling (the degree of capacitive coupling at each area) can be increased. Signal controller 24 may be programmed to recalculate a larger area of contact regions 50, 52, 54, 56, 58 and/or to detect an increase in capacitive coupling according to methods known in the art and transmit a signal to device controller 32 indicating a tighter grip.

Thus, in embodiments of the present invention, solid state touchpad 20 may be embedded with a capacitive touch sensor that is capable of detecting multiple touches, and the characteristics of user contact may be inferred by analyzing various parameters sensed by the touch sensor. For example, the position of the user's fingers and palm may be inferred from the shape and area of each multi-touch. The centroid of each touch zone can be calculated and the movement of the centroid can be tracked in real time to enable determination of the displaced position of the hand, for example if the user's hand is slid over the control element. The strength of the user's grip on the control element and the relative coupling of each touch point can be inferred from the size of the area of each of the multiple touches.

It should be noted that the information obtained by analyzing the parameters sensed and determined from the touch sensor can be applied to a wide variety of uses in machine control algorithms. As shown in fig. 7-9, for example, a vehicle steering column 62 generally includes a column 64 and a steering wheel 66. Steering wheel 66 generally includes a core 68 that may be partially or fully covered with a solid sensing board 70, which is in turn covered by a housing 72, housing 22. The core 68 may have finger grips 69 formed therein. A signal processor 74 communicatively connected to the solid state sensing board 70 may be housed in the column 64 or steering wheel 66 as shown. In accordance with embodiments of the present invention, solid state sensing pads 70 in conjunction with signal processor 74 may be used to detect user contact at contact areas 76, 78. Further, the area of each contact region 76, 78 may be calculated, and a respective centroid 80, 82 may be determined for each contact region 76, 78, which may be determined by methods known in the art. This information may be used to determine whether the driver is holding the steering wheel with both hands in the appropriate "10 o 'clock and 2 o' clock positions" on the steering wheel, as shown, for example, in fig. 8. The duration of contact at each contact region 76, 78 may also be determined. If the driver removes one hand from the steering wheel for more than a few seconds (e.g., sending a text message with a mobile phone), or if the driver's hand slips as shown, the position of the centroid 80 (indicated by the arrow) of the contact region 76 changes, the control algorithm in the onboard computer of the automobile may be programmed to emit a sound to alert the driver to place both hands on the steering wheel. If the warning is not noticed for a period of time, an algorithm in the on-board computer may reduce engine power or apply vehicle brakes to slow or stop the vehicle.

In another embodiment, a touch sensor according to the invention may be embedded in a gear shift lever of a vehicle and arranged to detect whether a user holds the gear shift lever in some suitable way. If the lever is held in an appropriate manner and then a shift from neutral to drive is made, an algorithm in the vehicle's on-board computer can be programmed to cause the transmission to effect the shift as instructed. However, if the lever is not held in an appropriate manner, such as if the lever is merely accidentally bumped into forward gear, the algorithm will cause the transmission to ignore the shift and remain in neutral.

It should also be noted that the present invention is not limited to a particular type of control element, but may be used with any type of control element that is controlled by contact with the body of the user. For example, but not limiting of, the present invention may be embedded in joysticks, steering wheels, levers, poles, buttons, other types of hand or foot controls, and any other type of control controlled by contact.

It should also be noted that other types of sensors may be used instead of or in addition to capacitive touch sensors. For example, an infrared or thermal sensor may be embedded in the control element to detect the amount or character of touch by sensing the body temperature of the user. Such sensors may be used to augment information derived from capacitive touch sensors that are also embedded with control elements, or used alone in certain applications.

It should also be noted that the invention described herein can be applied to control elements of virtually any shape and size and to solid state sensors in virtually any location on the control element. The solid state sensor may be made of a flexible and/or resilient polymeric material having suitable dielectric properties in the case of a capacitive touchpad, and may be configured to conform to the geometry of the control element. For example, the solid state sensor may conform to the generally cylindrical shape of a joystick as shown in FIG. 1, or a steering wheel shape in a more geometrically complex shape as shown in FIGS. 7-9. In other embodiments, the solid state sensor may conform to the shape of a control or shift lever, and may even be shaped to conform to a finger grip formed therein.

The foregoing description has described numerous specific details that may provide a thorough understanding of various embodiments of the invention. It will be apparent to one skilled in the art that the various embodiments disclosed herein may be practiced without some or all of these specific details. In other instances, components well known in the art have not been described in detail herein in order to avoid unnecessarily obscuring the present invention. It is to be understood that even though numerous characteristics and advantages of various embodiments have been set forth in the foregoing description, the disclosure, together with details of the structure and function of various embodiments, are illustrative only. Other embodiments may be constructed which still use the principles and spirit of the invention. This application is therefore intended to cover any adaptations or variations of the present invention.

It is clear that for the purposes of interpreting the claims of this invention, the provisions of article 6, volume 112, of the american code, law, should not be cited unless a specific term "means" or "step" is re-listed in a claim.

Claims (21)

1. A control system for a device, comprising:

a control device having a contact surface;

a solid state touchpad overlying at least a portion of the contact surface of the control device; and

a signal processor communicatively connected to the solid state touch pad, the signal processor programmed with an algorithm to determine at least one real-time parameter relating to contact of a user's body with the solid state touch pad.

2. The control system of claim 1, wherein the signal processor is communicatively coupled with a memory, and wherein at least one predetermined threshold parameter is defined and stored in the memory.

3. The control system of claim 2, wherein the signal processor is programmed to compare the at least one real-time parameter to the at least one threshold parameter, and wherein the signal processor transmits a signal indicating whether the at least one threshold parameter is met by the at least one real-time parameter.

4. The control system of claim 1, wherein the solid state touch pad is a capacitive touch pad.

5. The control system of claim 1, wherein the contact surface is in a complex geometry.

6. The control system of claim 1, wherein the at least one real-time parameter comprises an area of user contact with the control device.

7. The control system of claim 1, wherein the at least one real-time parameter comprises a location of an area contacted by a user on the control device.

8. The control system of claim 1, wherein the at least one real-time parameter comprises a centroid of an area of user contact with the control device.

9. The control system of claim 1, wherein the at least one real-time parameter comprises a duration of user contact with the control device.

10. The control system of claim 1, wherein the at least one real-time parameter includes an amount of change in a location of an area contacted by a user on the control device.

11. The control system of claim 1, wherein the control device is selected from the group consisting of a joystick, a steering wheel, a control lever, and a shift lever.

12. The control system of claim 1, wherein the signal processor is programmed with an algorithm to determine a plurality of real-time parameters relating to contact of a user's body with the solid state touchpad.

13. The control system of claim 12, wherein the signal processor is communicatively coupled with a memory, and wherein a plurality of predetermined threshold parameters are defined and stored in the memory, each predetermined threshold parameter corresponding to a separate one of the real-time parameters.

14. The control system of claim 13, wherein the signal processor is programmed to compare each real-time parameter to the corresponding threshold parameter, and wherein the signal processor transmits a signal indicating whether each threshold parameter is reached by its corresponding real-time parameter.

15. The control system of claim 1, further comprising a device controller communicatively coupled with the signal processor, the device processor adapted to control a piece of equipment.

16. A method of controlling a vehicle or device, the method comprising:

placing a solid state touch pad on at least a portion of a user interface of a control device of the vehicle or apparatus;

communicatively connecting a signal processor with the solid state touch pad; and

the signal processor is programmed with an algorithm to determine at least one real-time parameter relating to contact of a user's body with the solid-state touchpad.

17. The method of claim 16, further comprising communicatively coupling the signal processor with a memory and storing at least one predetermined threshold parameter in the memory.

18. The method of claim 17, further comprising programming the signal processor to compare the at least one real-time parameter to the at least one threshold parameter and programming the signal processor to transmit a signal indicating whether the at least one threshold parameter is met by the at least one real-time parameter.

19. The method of claim 16, further comprising programming the signal processor with an algorithm to determine a plurality of real-time parameters regarding contact of a user's body with the solid state touchpad.

20. The method of claim 19, further comprising communicatively coupling the signal processor with a memory and storing a plurality of predetermined threshold parameters in the memory, each predetermined threshold parameter corresponding to a separate one of the real-time parameters.

21. The method of claim 20, further comprising programming the signal processor to compare each real-time parameter to the corresponding threshold parameter and programming the signal processor to transmit a signal indicating whether each threshold parameter is reached by its corresponding real-time parameter.