The present invention generally relates to devices and methods for providing haptic effects. This invention more particularly relates to a haptic actuator capable of providing resistive and vibrotactile feedback.
A haptic actuator provides tactile sensations to a user of an interface device incorporating the actuator. The actuator may be active or resistive. An active actuator may provide feedback to the user through kinesthetic or vibrotactile effects. The active actuator moves an interface device, such as a manipulandum, or imparts a vibration in the device. In contrast, a resistive actuator requires that a user move an input device. The resistive actuator then provides haptic feedback by resisting the movement.
Conventional interface devices typically incorporate either an active or resistive actuator. An interface device will typically not incorporate both an active and passive actuator because of the complexity, size, and expense of incorporating two separate actuators.
Thus a need exists for a compact and efficient actuator capable of providing effective resistive and vibrotactile feedback.
An embodiment of the present invention provides resistive and vibrotactile effects. One embodiment of the present invention comprises a manipulandum and a resistive haptic actuator configured to generate a resistive haptic force in order to generate a vibrotactile haptic effect.
This embodiment is mentioned not to limit or define the invention, but to provide an example of embodiments of the invention to aid understanding thereof. Embodiments are discussed in the Detailed Description, and further description of the invention is provided there. Advantages offered by the various embodiments of the present invention may be further understood by examining this specification.
These and other features, aspects, and advantages of the present invention are better understood when the following Detailed Description is read with reference to the accompanying drawings, wherein:
Embodiments of the present invention comprise devices and methods for providing resistive and vibrotactile effects. Referring now to the drawings in which like numerals indicate like elements throughout the several figures,
A device according to the present invention may provide haptic feedback in various manipulanda, such as the knob (108) shown in
The knob 202 is mounted on a shaft 204 to allow the knob 202 to rotate in a plane perpendicular to the shaft 204. The shaft 204 is shown mounted to the bottom of the knob 202 in
On the side of the knob 202 shown in
The electromagnetic brake 206 comprises a core (not shown) and a magnetic coil (not shown) wrapped around the core. These elements are shown in further detail in
In the embodiment shown, the electromagnetic brake 206 performs multiple functions. The brake 206 exerts a resistive force on the knob 202 as described above. The brake 206 is also configured to provide a vibrotactile feedback to the knob 202. The dual actuation may be performed in various ways. For example, the full actuator may perform dual actuation, i.e., the entire actuator may vibrate and impart a vibration on the knob 202. Alternatively, the actuator may comprise multiple coils, which are energized independently within the actuator based on whether a resistive or vibrotactile effect is desired. In yet another embodiment, the actuator passes the magnetic flux created by both types of actuation through the same core.
The electromagnetic brake 206 provides vibrotactile feedback directly to the underside of the knob 202. In other embodiments, the actuator provides a resistive effect to the manipulandum and provides vibrotactile feedback through a ground, such as through the housing of the device housing the manipulandum. For example, the electromagnetic brake 206 may be configured to contact the housing, imparting a vibration on the housing in which the knob, or other elements of the interface, is installed.
The electromagnetic brake may be formed in various shapes. In the embodiment shown, the electromagnetic brake 206 is shaped like a cube, having six sides. The view shown in
The embodiment shown also comprises a spring 210. A first end of the spring 210 is attached to the side of the electromagnetic brake 206 opposite the braking surface. The other end of the spring 210 is attached to a ground 212. When the electromagnetic brake 206 vibrates, it induces a vibration in the spring 210. The spring 210 continues to vibrate after power to the electromagnetic brake 206 ceases. The spring 212 also serves to smooth the actuation of the electromagnetic brake 206. By varying the spring constant (natural frequency) during design, the designer of the actuator is able to tune and refine the characteristics of the vibrotactile feedback produced by the brake 206. Although the embodiment shown comprises a spring 210, the spring 210 is not necessary to provide resistive or vibrotactile feedback.
In the embodiment shown, the electromagnetic brake 306 is a cube with an additional side 307 forming an angle between two adjacent sides, i.e., the cube has seven sides. The view shown in
The embodiment shown also comprises a spring 312. A first end of the spring 312 is attached to a side 313 of the electromagnetic brake 306 adjacent to a corner opposite the braking surface 307. The other end of the spring 312 is attached to a ground 314. Although the embodiment shown comprises a spring 312, the spring 312 is not necessary to provide resistive or vibrotactile feedback. When no current is applied to the electromagnetic brake 306, the spring 312 biases the angled side 313 flat up against the knob 302. When current is applied to the electromagnetic brake, the larger, flat surface of the electromagnetic brake 306 is attracted to the knob 302.
A mass 412 is connected to the electromagnetic brake 406. The shape of one side of the mass 412 corresponds to the indentation formed in the electromagnetic core 406 so that a portion of the mass 412 is situated within the indentation. In the embodiment shown, the mass 412 is connected to the electromagnetic core by a spring 412. Other types of connectors may be used. When the electromagnetic core 406 is energized, the mass 412 is drawn towards the core 406.
One end of a spring 414 is attached to the mass 412. The other end of the spring 414 is attached to a ground 416. Two additional springs 418a,b are present in the embodiment shown. One end of each of the springs 418a,b is attached to the electromagnetic brake 406. The other end of each of the springs 418a,b is attached to the ground 416. The spring constant of springs 418a,b are relatively large to provide bias of the electromagnetic brake 406 against the knob 402. The spring constant of spring 412 and spring 414 are relatively small.
A second side 510 of the electromagnetic brake 506 opposite the knob 502 separated from the rest of the electromagnetic brake and attached by a spring 512. When the electromagnetic brake 506 is energized, electromagnetic brake 506 is drawn towards the knob 502 and the separated side 510 moves towards the electromagnetic brake 506 to complete the magnetic circuit. In vibrotactile mode, the separated side 510 is repeatedly and quickly drawn toward the bottom of the electromagnetic brake, creating vibrotactile effects. In the embodiment shown, the gap 512 between the separated side 510 and the electromagnetic brake 506 is greater than the gap 508 between the electromagnetic brake 506 and knob 502. The spring constant and the gap 512 can both be tuned to provide a useful resonance.
On one side of the electromagnetic brake 606, perpendicular to the first side, is a slug 610. The slug 610 is a small piece of metal influenced by the magnetic field produced by the electromagnetic core 606. The slug 610 is configured to directly contact the manipulandum 602 and provide vibrotactile feedback when current is applied to the electromagnetic brake 606. The slug 610 is attached to the electromagnetic brake 606 such that the slug 610 can move up and down in relation to the electromagnetic brake 606, for example, in a sleeve attached to the electromagnetic brake 606. The slug 610 is attached to a spring 612. The spring 612 is attached a ground 614, which is attached to the electromagnetic brake.
The electromagnetic brake 706 in the embodiment shown is a pot core. The pot core has a central core 709 around which a coil 711 is situated with an intentionally large gap. Mounted proximate to the central core 709 are two voice coils 710a,b. The plunger (not shown) of each of the voice coils 710a,b are attached to a shaft 712a,b. The shafts 712a,b are further attached to a mass 714. When the coil of the pot core is energized the voice coils 710a,b extend. When the polarity is reversed, the voice coils 710a,b retract. In one embodiment, the coil of the electromagnetic brake 706 and of the voice coils 710a,b is energized separately. In such an embodiment, the flux flows through the same steel. In one embodiment, a spring is present between the mass 714 and the electromagnetic brake 706 and is used in a manner similar to the manner in which springs are used in the other embodiments described herein.
The electromagnetic brake 806 in the embodiment shown is an E-core. The E-core has a first side comprising projections. In the embodiment shown, the projections are closest to the manipulandum 802.
The electromagnetic brake 806 is attached to a mass 810 by three springs 812a,b,c. Also attached to the electromagnetic brake 806, between the electromagnetic brake 806 and the mass 810 is a magnetic coil 814. The magnetic coil 814 shown is separate from the coil utilized by the electromagnetic brake 806 to provide resistive force. The magnetic coil 814 serves to move the mass 810 towards and away from the electromagnetic brake 806, causing vibrotactile feedback.
In another embodiment of the present invention, a permanent magnet is mounted on the bottom of the secondary coil by a spring. Actuation of the secondary coil causes the permanent magnet to be drawn towards the secondary coil. In yet another embodiment, the mass 810 or permanent magnet is grounded. The secondary coil 814 moves up and down, for example, on springs, causing vibrotactile feedback.
The electromagnetic brake 906 in the embodiment comprises a base 914. Mounted on the base is a block of magneto-strictive material 912. In the embodiment shown, the block of magneto-strictive material 912 is surrounded by a magnetic coil 914, which is also mounted on the base 910. When a magneto-strictive material becomes magnetized, it changes shape. The extent of the change is proportional to the intensity of the magnetic field but is not dependent on the polarity of the field. Materials having positive magneto-striction expand in the direction of the magnetic field; materials having negative magneto-striction expand in a direction opposite the magnetic field.
When the magnetic coil 914 is energized, the block of magneto-strictive material expands and provides a restive force on the manipulandum 902. Magneto-strictive materials can exert high forces and the change in shape has relatively low hysteresis. In the embodiment shown, the magneto-strictive material is Terfenol, which consists of Terbium (Te) and iron (Fe). Other magneto-strictive materials may also be used, such as nickel and cobalt.
Also attached to the magneto-strictive material 912 is a mass 916. The mass 916 is attached to the magneto-strictive material 912 by a spring 918. The spring 912 is attached to the magneto-strictive material 912 so that the mass 916 moves up and down as the magneto-strictive material expands and contracts, resulting in vibrotactile feedback.
In any of the embodiments shown in
The sensor is in communication with a processor. The processor receives the position signal 1002. The processor includes program code on a computer-readable medium that includes instructions for generating an actuator signal based, at least in part on the position signal. For example, the processor may access a table that specifies the type, magnitude, frequency, etc. of an actuator signal to output based on the position signal and the status of a current application program a user is interacting with. For example, the table may indicate that if a user is accessing a heating ventilation and air conditioning (HVAC) application in an automobile and is currently adjusting the fan speed, a particular actuator signal is to be output at the position indicated by the position signal. The processor generates the signal 1004 and transmits the signal to an actuator 1006, such as the actuators shown in
The actuator receives the signal and, in response, generates a resistive force configured to cause a vibrotactile effect 1008. The vibrotactile effect may be output on the manipulandum or the housing. The actuator may be affixed to a spring. In such a case, the actuator signal may be configured to cause a resonance in the spring, thereby modifying the vibrotactile effect generated by the actuator.
In the embodiment shown in
The processor is in communication with the actuator and with a sensor that reads the position of the manipulandum and provides the position data to the processor. The processor may comprise, for example, a digital logic processor capable of processing input, executing algorithms, and generating output as necessary in response to the inputs received from the knob or from other input devices. Such processors may comprise a microprocessor, an ASIC, and state machines. Such processors comprise, or may be in communication with, media, for example computer-readable media, which stores instructions that, when executed by the processor, cause the processor to perform the steps described herein. Embodiments of computer-readable media comprise, but are not limited to, an electronic, optical, magnetic, or other storage or transmission device capable of providing a processor, such as the processor in communication with a touch-sensitive input device, with computer-readable instructions. Other examples of suitable media comprise, but are not limited to, a floppy disk, CD-ROM, magnetic disk, memory chip, ROM, RAM, an ASIC, a configured processor, all optical media, all magnetic tape or other magnetic media, or any other medium from which a computer processor can read instructions. Also, various other forms of computer-readable media may transmit or carry instructions to a computer, comprising a router, private or public network, or other transmission device or channel, both wired and wireless. The instructions may comprise code from any computer-programming language, comprising, for example, C, C++, C#, Visual Basic, Java, and JavaScript. The processor may contain code for carrying out the methods described herein.
Embodiments of the present invention provide numerous advantages over conventional interface elements. For example, in a conventional device providing both resistive and vibrotactile feedback, at least two actuators are necessary, one for each effect. An embodiment of the present invention utilizes a single actuator to provide both effects. Accordingly, embodiments of the present invention are less expensive and require fewer discreet components. An embodiment of the present invention also provides increased functionality of the vibrotactile effect set being added to that of a resistive device, even when the target is not moving rotationally.
Embodiments of the present invention may be implemented in various environments and devices. For example, many cell phones and personal digital assistants employ scroll wheels to navigate within user interfaces. An embodiment may also be utilized by a remote control or on a DVD player control, such as a jog/shuttle.
The foregoing description of embodiments of the invention has been presented only for the purpose of illustration and description and is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Numerous modifications and adaptations thereof will be apparent to those skilled in the art without departing from the spirit and scope of the present invention.
This application is a divisional application of co-pending U.S. patent application Ser. No. 10/934,142 entitled “Device and Methods for Providing Resistive and Vibrotactile Effects” filed Sep. 3, 2004, the entirety of which is hereby incorporated by reference.
Number | Date | Country | |
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Parent | 10934142 | Sep 2004 | US |
Child | 11869588 | Oct 2007 | US |