A multi-dimensional track pad is described that acts as human-machine interface (HMI). Inputs to the HMI can be made not only using the tradition two-dimensional (X-Y) inputs of a track pad, but also a third dimension, force, and even a fourth dimension, time. Tactile or audible feedback to the inputs can be provided. Methods of using the HMI to control a system are described as well as a track pad system that utilizes the HMI in communication with a processor.

BACKGROUND

Conventional control systems present operators with a combination of controls such as switches, buttons, levers, knobs, dials, etc. The operators interact with these control systems by manipulating the presented controls in order to execute various control functions. Recently, control systems have become increasingly complex due to the growing number of controllable features. As control systems increase in complexity, control panels become cluttered with switches, buttons, levers, knobs and/or dials. Accordingly, the control systems become more difficult to operate. In addition, it becomes difficult for engineers to design control panels that are capable of accommodating all of the necessary controls within a confined space.

Track pad devices have been developed to address the problems in the related art. However, these devices are generally two-dimensional (X-Y). For example, some smart phone devices include optical track pads for navigating the graphical user interface (GUI) of the smart phone. The optical track pads have a pleasant tactile feel, provide an audible “tick” for each move and, unlike capacitive touch screens, can be used without direct skin contact. For example, capacitive touch screens do not work with gloves. Some optical track pads do work with gloves; however, because they use a mechanical contact that is separate from the track pad for accept or select functions. Furthermore, optical track pads generally have a fairly low resolution infrared camera susceptible to moisture (sweat) interferences and are limited to measurements in two (X-Y) dimensions.

SUMMARY

Embodiments of the present invention relate to force based track pads for human-machine interfaces (HMI) and in particular track pads capable of sensing forces as well as position and providing tactile and audible feedback.

Described herein is an embodiment of a method of controlling a system using a track pad. The exemplary method comprises a touch interface of a track pad receiving a touch force. The touch interface is positioned over an array of force sensors that are arranged to have a width and a length. The method further comprises passing at least a portion of the touch force through the touch interface to one or more force sensors of the array of force sensors. The one or more force sensors of the array of force sensors transmits the force information to a processor in communication with the array of force sensors. The processor determines from the force information, a force position along the width and length and a corresponding force magnitude. The processor sends a control message to a system, wherein the control message is selected depending upon one or more of the force position along the width and length and the corresponding force magnitude. A feedback generator provides at least one of a tactile or audible feedback to the user of the track pad.

Also described herein is a track pad system that can be used to practice embodiments of the described method. In one aspect, the track pad system comprises a two-dimensional array of force sensors arranged to have a width and a length and a touch interface positioned over the array, wherein the touch interface passes touch forces through to one or more force sensors of the array of force sensors. A processor in communication with a memory executes computer-readable instructions stored on the memory, the instructions cause the processor to receive force information from the array of force sensors; and determine a force position along the width and length and a corresponding force magnitude. The track pad system is further comprised of a feedback generator that generates at least one of a tactile or audible feedback.

A track pad system integrated into a steering mechanism of a vehicle is also described herein. The system comprises a two-dimensional array of force sensors arranged to have a width and a length, the two dimensional array of force sensors embedded into a steering mechanism of a vehicle. The touch interface is positioned over the array, wherein the touch interface passes touch forces through to one or more force sensors of the array of force sensors. The system further comprises a processor in communication with a memory, wherein the processor executes computer-readable instructions stored on the memory, the instructions cause the processor to receive force information from the array of force sensors; determine a force position along the width and length and a corresponding force magnitude; and send a control message to a system, wherein the control message is selected from a plurality of control messages and the system is selected from a plurality of systems depending upon one or more of the force position along the width and length and the corresponding force magnitude.

It should be understood that the above-described subject matter may also be implemented as a computer-controlled apparatus (e.g., a human machine interface for a system), a computing system, or an article of manufacture, such as a computer-readable storage medium.

DETAILED DESCRIPTION

Described herein are embodiments of an invention that include a track pad system for recording multi-dimensional data including an X-Y direction and a force magnitude.

FIG. 1illustrates a plan view of an exemplary steering apparatus implementing a force-based track pad interface for vehicle control panels in accordance with the present disclosure. An example steering apparatus100can have a steering grip102. A steering grip102can be shaped in such a way to facilitate a driver's control of a vehicle when holding the steering grip102. For example, the steering grip102can include an annular ring shape with an outer contour that is essentially circular in shape. In an alternate implementation, the steering grip102can define any suitable shape including, for example, circular, elliptical, square, rectangular, or any other regular or irregular shape. In an exemplary implementation, the steering grip102can include a single continuous grip portion or any number of unique grip sections. Additionally the steering grip102can be mounted on a fixed component104such that it can be rotationally moved about a steering axis. An exemplary fixed component104can include, for example, a steering column, which receives a steering spindle that extends along the steering column and serves to transmit the rotational movement of the steering grip102to the wheels of the motor vehicle. Rotational movement of the steering grip102may be transmitted to the wheels by mechanical and/or electrical means. In an exemplary implementation, the steering apparatus100can also include a force-based track pad sensor106, wherein the force-based track pad sensor106is operably coupled to the steering grip102.

Coupling a force-based track pad sensor106to the steering grip102of a steering apparatus100provides a driver with a human-machine interface that can be configured to detect a touch or force provided by a user and determine if a switch function should or should not be activated. In one embodiment, the user can be provided with a tactile or audible feedback response.

A force-based track pad sensor106can be any sensor configured to change at least one electrical property in response to a touch or force applied to the sensor106. A touch, also known as a touch event, can be for example a physical contact that occurs when a driver in a vehicle uses their hand (gloved or ungloved) to apply a force to force-based track pad sensor106. A force-based track pad sensor106, can be any suitable tactile sensor including, a mechanical sensor, a resistive sensor, a capacitive sensor, a magnetic sensor, an optical fiber sensor, a piezoelectric sensor, a silicon sensor, and/or a temperature sensor.

The force-based track pad sensor106can include a two-dimensional array of force sensors arranged to have a width and a length, where each force sensor includes conductors and electrodes and is in at least partial contact with a touch interface positioned over the array. In one embodiment the track pad sensor106can further comprise a base that is in at least partial contact with each of the force sensors. In one aspect, the base can comprise a printed circuit board. The touch interface passes touch forces to one or more force sensors of the array of force sensors. The touch interface can embody any touch-sensitive deformable member that can pass at least part of the forces from a user through the touch interface to one or more force sensors of the array of force sensors. In one embodiment, the touch interface can be used to provide haptic feedback to the user.

Referring toFIG. 2, a block diagram of a force-based track pad sensor system200according to an implementation of the invention is shown. The sensor system200is an example of a human machine interface for controlling a system as discussed in further detail below. The sensor system200may be used to sense a position and magnitude of force applied to the sensor system200. In other words, the sensor system200may be configured to sense the position of the applied force in either one dimension (e.g., the X- or Y-direction) or two dimensions (e.g., the X- and Y-directions), as well of as the magnitude of the applied force (e.g., force in the Z-direction). The sensor system200can also be configured to sense the time that a force is applied at a particular location. The sensor system200may include a computing unit206, a system clock208, one or more force sensors210and communication hardware212. In its most basic form, the computing unit206may include a processor202and a system memory204. The processor202may be a standard programmable processor that performs arithmetic and logic operations necessary for operation of the sensor system200. The processor202may be configured to execute program code encoded in tangible, computer-readable media. For example, the processor202may execute program code stored in the system memory204, which may be volatile or non-volatile memory. The system memory204is only one example of tangible, computer-readable media. In one aspect, the computing unit206can be considered an integrated device such as firmware. Other examples of tangible, computer-readable media include floppy disks, CD-ROMs, DVDs, hard drives, flash memory, or any other machine-readable storage media, wherein when the program code is loaded into and executed by a machine, such as the processor202, the machine becomes an apparatus for practicing the disclosed subject matter.

In addition, the sensor system200may include one or more force sensors210that can change at least one electrical property (e.g., resistance) in response to forces applied to the sensor system200. The force sensor210is an example of a pressure sensitive input device as discussed in further detail below. Further, the sensor system200may include communication hardware212that interfaces with the force sensor210and receives/measures the sensed changes in the at least one electrical property of the force sensor210. Additionally, the sensor system200may include a system clock208. The processor202may be configured to associate the sensed changes in the at least one electrical property of the force sensor210with a time from the system clock208and store the sensed changes and corresponding time to the system memory204. Optionally, the processor202may be configured to analyze the stored data and associate measured changes in the at least one electrical property of the force sensor210with various control messages for controlling system functions.

FIGS. 3A and 3Billustrate a cross-sectional view and a plan view of an embodiment of a force-based track pad300. This embodiment of a force-based track pad300includes a two-dimensional array of force sensors302arranged to have a geometric shape having a width304and a length306. For example, the array of force sensors302may have a width304or length306that is 8 mm or larger. In another example, the array of force sensors302may have a width304or length306that is less than 8 mm. In one embodiment, the track pad300can have a depth314that is 0.5 mm or less. In another example, the track pad300can have a depth314that is greater than 0.5 mm. While shown inFIGS. 3A and 3Bas having a rectangular shape, it is to be appreciated that this is for illustrative purposes only and the two-dimensional array of force sensors302can have shapes such as circular, oval, square, rectangular, triangular and irregular shapes. Further comprising the embodiment of a force-based track pad300as shown inFIGS. 3A and 3Bis a touch interface308positioned over the array of force sensors302, wherein the touch interface308passes touch forces through to one or more force sensors302of the array of force sensors302. As described herein, the touch interface308can embody any touch-sensitive deformable member that can pass at least part of the forces from a user through the touch interface308to one or more force sensors302of the array of force sensors302. For example, the touch interface308can be comprised of rubber, plastics, flexible metals, leather, and the like including combinations thereof. Generally, the force sensors302are connected to or integrated with a base310. For example, the base310can comprise a printed circuit board (PCB) used to electronically communicate information or power to and from the force sensors302in the form of electrical signals. In various embodiments, the base310can further comprise electronic circuit components such as resistors, capacitors, diodes, LEDs, transmitters, receivers, and the like. In one embodiment, the base310is used to electrically connect the force sensors302with a processor202, as described herein.

The force sensors302are arranged such that the position of a force on the touch interface308can be detected by one or more of the force sensors302of the array of force sensors302. In this manner, by the force sensors302affected by the force on the touch interface308and the magnitude of the force on each of the affected force sensors302, the position (X, Y) of the force on the touch interface308can be determined. For example, force information from the array of force sensors can be transmitted to a processor such as the processor202shown inFIG. 2and described herein. The processor202can be in communication with a memory204, wherein the processor202executes computer-readable instructions stored on the memory204. The instructions can cause the processor202to receive the force information from the array of force sensors302and determine a force position along the width304and length306and a corresponding force magnitude. The force information can be transmitted from the array of force sensors302to the processor202via a wired connection (including fiber optics, wirelessly (RF using protocols such as Bluetooth™, WiFi (IEEE 802.11n), etc.), or combinations thereof. For example, referring now toFIG. 3B, the processor can receive force information from force sensors c, d, g, and h. By having the location of these force sensors302programmed into its memory204, the processor202can determine that a force is being applied to the upper right-hand quadrant of the force-based track pad300. By determining the magnitude of the force being applied to the force sensors302, the processor202can be programmed via instructions from the memory204to further refine the location of the force and to take specific actions based on any of the location of the force on the track pad300, the magnitude of the force applied to the track pad300, the time the force is applied to the track pad300, the change of the location of the applied force to the track pad300, the rate of the change of the location of the applied force to the track pad300(e.g., quickly swiping a thumb across the track pad300results in one action being taken while slowly swiping the thumb across the track pad300results in a different action being taken), the direction of the change of the location of the applied force to the track pad300, the length from a first touch point to a second touch point on the track pad300, the length or distance that a digit is moved across the track pad300after a first touch point, the direction that a digit is moved across the track pad300after a first touch point, changes in the magnitude of the force applied to the track pad300, rate of change in the magnitude of the force applied to the track pad300, combinations of any of the above, and the like.

Referring back toFIG. 3A, the force sensors302can be any device or structure that can transform force into a signal. The signal can be electrical, electronic (digital or analog), mechanical, or optical. For example, in one embodiment the force sensors are microelectromechanical systems (MEMS) sensors. In one embodiment, the MEMS sensors are structure-based piezo-resistive sensors.

FIG. 3Cillustrates another embodiment of a force-based track pad300that further comprises a feedback generator312that generates at least one of a tactile or audible feedback. In one aspect, the tactile or audible feedback provided by the feedback generator312is proportional to at least one of the force position and the force magnitude. For example, the tactile or audible feedback can get stronger or louder as greater force is applied to the track pad300. Similarly, the tactile or audible feedback can get stronger or louder depending upon the location on the track pad300where the force is applied. The feedback generator312may, in some embodiments, be controlled by the processor202. For example, the processor202may determine the location or magnitude of the force applied to the track pad300, as described herein, and then cause the feedback generator312to generate the tactile or audible feedback that is proportional to at least one of the force position and the force magnitude. Software stored in the memory204can cause the processor202to perform these functions. In one embodiment, the feedback generator312can be integrated into the structure that comprises the force-based track pad300. For example, in one embodiment the feedback generator312can be integrated into the base310. In another embodiment, the feedback generator312is a structural part of the structure-based piezo-resistive sensors, as described herein. In yet another embodiment, the feedback generator312is a haptic generator used to generate the tactile and audible feedback. In one embodiment, the haptic generator can be a coneless coil and magnet assembly such as that described in U.S. Pat. App. Pub. No. 2012/0039494 entitled “LOUDSPEAKERS” and filed on Feb. 16, 2010, which is fully incorporated herein by reference and made a part hereof.

The embodiments of a force-based track pad300described herein can be used to control one or more systems. For example, embodiments of a force-based track pad300described herein can be used to control the systems of a vehicle such as environmental (HVAC), audio, telephone, cruise control, windshield wipers, lighting, window and mirrors, and the like. For example, instructions stored in the memory204can further cause the processor202to send a control message to a system selected from a plurality of systems, wherein the control message is selected from a plurality of control messages by the processor202. The selection of system and control message can be made depending upon one or more of the force position along the width and length and the corresponding force magnitude. For example, in one embodiment the system can be selected from the plurality of systems depending upon the force magnitude and the control message is selected from the plurality of control messages depending at least partially upon the force position along the width and length. Consider this example, the force-based track pad300can have a plurality of force thresholds that can be used to select the system from the plurality of systems. For example, the force-based track pad300can have at least three thresholds that correlate to a different system for each threshold. In one example, the force thresholds are in increments of one Newton (N) or one ounce, two N or two ounces, and the like. For example, the first threshold may be at a force of one Newton (N) or one ounce and correlate to the audio system of a vehicle. The second threshold can be at two N or two ounces of force that correlates to the HVAC system for the vehicle. The third threshold can be at three N or three ounces of force that correlates to the cruise control system for the vehicle. In other words, the track pad300can recognize force magnitude of at least three thresholds and the system is selected from the plurality of systems depending upon the force magnitude exceeding one or more of the thresholds.

In one embodiment, once the system is selected from the plurality of systems based on the force magnitude, a control message for sending to that selected system can be selected from a plurality of control messages based at least in part on the force position along the width and length of the track pad300. For example, if the HVAC system is selected based on the force magnitude, then a control message such as turn on/off the heat, turn up/down the fan, adjust the temperature, etc., can be selected based at least in part on the force position along the width and length of the track pad300. For example, control messages to send to the selected system can be selected based on one or more of the time the force is applied to the track pad300at a certain location, the change of the location of the applied force to the track pad300, the rate of the change of the location of the applied force to the track pad300(e.g., quickly swiping a thumb across the track pad results in one action being taken while slowly swiping the thumb across the track pad300results in a different action being taken), the direction of the change of the location of the applied force to the track pad300, the length from a first touch point to a second touch point on the track pad300, the length or distance that a digit is moved across the track pad300after a first touch point, the direction that a digit is moved across the track pad300after a first touch point, changes in the magnitude of the force applied to the track pad300, changes in the magnitude of the force applied to the track pad300, rate of change in the magnitude of the force applied to the track pad300, combinations of any of the above, and the like.

In one embodiment, the feedback generator312can provide an audible tick or other sound when the control message is selected from the plurality of control messages depending at least partially upon the force position along the width and length and provide the tactile feedback for each selection made depending on the force magnitude. Alternatively, the feedback generator312can provide an audible tick for each selection made depending on the force magnitude and provide tactile feedback when the control message is selected from the plurality of control messages depending at least partially upon the force position along the width and length of the track pad300.

FIG. 3Dis a cross-sectional view of yet another embodiment of a force-based track pad300. This embodiment includes the two-dimensional array of force sensors302arranged to have a geometric shape having a width304and a length306, a touch interface308positioned over the array of force sensors302, wherein the touch interface308passes touch forces through to one or more force sensors302of the array of force sensors302, a base310, and a feedback generator312that generates at least one of a tactile or audible feedback. Further comprising the embodiment shown inFIG. 3Dis an enclosure316that encloses the components of the track pad300. The enclosure316can be comprised of any suitable material such as plastics, metals, and the like. It can be used to add structural integrity to the track pad300as well as to protect it from physical and/or environmental damage or contamination. The enclosure316may also facilitate manufacturing, installation or removal of the track pad300. Further illustrated inFIG. 3Dis an interchangeable overlay320so that different materials, colors, textures can be used for the track pad300, which can be used for an aesthetic effect of a larger device, such as a vehicle, where the track pad300is installed. This can also allow replacement of the overlay320if it becomes damaged, dirty or worn. Also shown inFIG. 3D, but not required, is the trim318of a larger device, such as a vehicle, where the track pad300is installed. For example, the trim318can be a part of the steering apparatus100shown inFIG. 1.

As noted herein, the force-based track pad can be used to select and control a plurality of systems. The table400ofFIG. 4illustrates examples of systems that can be selected and control messages that can be sent to the selected system. For example, the force-based track pad300can have a plurality of thresholds that correlate to a different system for each threshold. In one example application of an embodiment of the invention, as shown in the table400ofFIG. 4, the first threshold may correlate with the HVAC system for a vehicle. By selecting the first threshold by applying a defined amount of force (e.g., one N or one ounce) to the track pad300(either momentarily or for a defined period of time), the HVAC system can be selected and controlled using the track pad300. Once selected by the force applied to the track pad300, the track pad300can be used to select and send control messages to the HVAC system. Gestures or other actions using the track pad300that are at least partially dependent upon the position along the width and length of the track pad300can be used to send the control messages to the HVAC system. For example, control messages to send to the selected system can be selected based on one or more of the time the force is applied to the track pad300at a certain location, the change of the location of the applied force to the track pad300, the rate of the change of the location of the applied force to the track pad300(e.g., quickly swiping a thumb across the track pad results in one action being taken while slowly swiping the thumb across the track pad300results in a different action being taken), the direction of the change of the location of the applied force to the track pad300, the length from a first touch point to a second touch point on the track pad300, the length or distance that a digit is moved across the track pad300after a first touch point, the direction that a digit is moved across the track pad300after a first touch point, changes in the magnitude of the force applied to the track pad300, changes in the magnitude of the force applied to the track pad300, rate of change in the magnitude of the force applied to the track pad300, combinations of any of the above, and the like. For the exemplary HVAC system that has been selected, such control messages can include for example: Turn on/off; Adjust temperature; Adjust fan speed; Adjust mode (e.g., defrost, face and feet, just feet, etc.); Adjust seat heat/ventilation; and the like.

Similarly, a second force threshold can be correlated with a second system, such as an audio system of a vehicle. In one embodiment, the second threshold is at a force greater than the first threshold. In another embodiment, the second threshold can be at a force less than the first threshold. Similar to the above, once the audio system is selected using force on the track pad300, control messages can be sent to the audio system using gestures or other actions using the track pad300that are at least partially dependent upon the position along the width and length of the track pad300. For the audio system such messages can be, for example: Turn on/off; Adjust sound level; Adjust fade, balance, bass, treble, etc.; Adjust mode (e.g., radio, satellite radio, CD, auxiliary, etc.); and the like. Other systems, such as those shown inFIG. 4, can be selected and controlled in similar fashion.

The track pad system300disclosed herein may be particularly applicable to distracted environments, such as in automobile operation, wherein the human needs additional feedback to properly operate a machine. For example, the driver of an automobile is usually best visually focused on his or her surroundings during the driving task. The ability of the track pad system300to provide haptic and audible feedback makes for more sure and satisfying operation of various automobile systems. As described herein, the track pad system300may be used, for example, to operate stereo and/or climate controls. Each change of a station or degree could generate haptic and audible feedback. In addition, the provision of force sensitivity—and in particular thresholds—allows multiple layers of functionality from a single button. The advantage of this implementation is that the track pad300can replace a large number of controls and shrink the necessary reach range (and the amount of distraction) for the driver.

FIG. 5is an exemplary flowchart500that can be used to describe a method of controlling a system using a track pad. Steps of the method comprise Step502, receiving a touch force by a touch interface308positioned over an array of force sensors302that are arranged to have a width304and a length306. At Step504, passing at least a portion of the touch force through the touch interface308to one or more force sensors302of the array of force sensors302. At Step506, transmitting force information by the one or more force sensors302of the array of force sensors302, to a processor202in communication with the array of force sensors302. At Step508, determining, by the processor, from the force information, a force position along the width304and length306, and a corresponding force magnitude. At Step510, the processor sends a control message to a system, wherein the control message is selected depending upon one or more of the force position along the width304and length306and the corresponding force magnitude. In one aspect, as described herein, sending the control message to the system, wherein the control message is selected depending upon one or more of the force position along the width and length and the corresponding force magnitude, further comprises selecting the system from a plurality of systems and selecting the control message from a plurality of control messages, the selections made depending upon one or more of the force position along the width and length and the corresponding force magnitude. In one embodiment, the system is selected from the plurality of systems depending upon the force magnitude and the control message is selected from the plurality of control messages depending at least partially upon the force position along the width and length. For example, the force magnitude can have at least three thresholds and the system is selected from the plurality of systems depending upon the force magnitude exceeding one or more of the thresholds. In one aspect, a different system is selected for each threshold. In another embodiment, the control message is selected depending upon the force magnitude exceeding a threshold, wherein the force magnitude has at least three thresholds and the control message is selected depending upon the force magnitude exceeding one or more of the thresholds. In one aspect, a different control message is selected for each threshold. At Step512, a feedback generator provides at least one of a tactile or audible feedback. In one aspect, the feedback generator provides a tactile or audible feedback that is proportional to at least one of the force position and the force magnitude. For example, the feedback may get louder, more frequent, more powerful, quieter, less powerful, etc. depending upon the force applied to the track pad300or at least partially upon the force position. In one embodiment, the feedback generator can be configured to provide an audible tick or other sound when the control message is selected from the plurality of control messages depending at least partially upon the force position along the width and length and provide the tactile feedback for each selection made depending on the force magnitude.