A tactile transmission method for identifying virtual buttons on cockpit smart surfaces

Abstract

The present invention discloses a tactile transmission method for identifying virtual buttons on a cockpit smart surface, comprising: obtaining the pressure of pressing the virtual button through a pressure sensor, realizing the button function and providing normal response feedback when pressing hard, and helping the user identify the button only through a tactile transmission method when pressing lightly, comprising: step 1, constructing a set of stimulus signals, presenting the stimulus signals to the user in pairs for subjective difference scoring, and obtaining a comparative distance matrix for each pair of stimuli; step 2, calculating a reduced two-dimensional coordinate matrix of the stimuli through a multidimensional scaling algorithm; step 3, when the stimuli in the two-dimensional graph are uniformly distributed, there exists a set M of m stimuli with the largest difference sum, and the distances between the stimulus pairs in the set are all greater than the standard deviation, then determining this set of stimuli as the stimulus set with the highest discriminability; when no stimulus set that meets the conditions exists in the graph, adding a new stimulus signal to step 1, comparing it with the existing stimuli, and repeating steps 2 and 3.

Description

Technical Field

[0001] The present invention relates to a tactile transmission method for identifying virtual buttons on a cockpit smart surface, and belongs to the field of human-computer interaction. Background Art

[0002] With the development of intelligent car interiors, interior decoration and user interfaces have evolved from physical buttons to clean and harmonious surfaces. Smart surfaces are distributed in various positions in the cockpit. They are a combination of car interior aesthetics and human-machine interface technology. They upgrade traditional mechanical interaction media such as buttons in traditional car interiors to touch interaction media with surface materials such as plastic or wood.

[0003] The user's perception of control buttons can be divided into search tactile and confirmation tactile. Search tactile is about how to use tactile cues to best support users in finding interactive areas, distinguishing adjacent control elements, and providing directions to users on the surface. Confirmation tactile refers to clear and specific tactile feedback used to change the operating status of control elements. Currently, the virtual buttons in the interactive area of smart surfaces in the cockpit lack tactile feedback, or the tactile feedback of each button is single, and only provides confirmation tactile feedback when touched, which does not help users perform tactile search. In order to reduce the visual needs of drivers and passengers, it is particularly important to develop interactive surfaces that not only ensure the smoothness of the interactive surface, but also help users restore the tangibility of virtual buttons and even recognize button functions without eyes. Summary of the Invention

[0004] The present invention designs and develops a tactile transmission method for identifying virtual buttons on the intelligent surface of the cockpit. Through a multi-dimensional scaling algorithm, a method for creating distinguishable vibration signals in the same way for different numbers of virtual buttons is adopted, so that different virtual buttons can correspond to stimuli with recognizable differences, realizing a method for creating distinguishable vibration signals in the same way.

[0005] The technical solution provided by the present invention is:

[0006] A tactile transmission method for identifying virtual buttons on a cockpit smart surface, comprising:

[0007] The pressure sensor detects the pressure applied to the virtual key. When pressed hard, the virtual key responds normally to the finger, reminding the user that the operation was successful. When pressed lightly, tactile transmission methods are used to help the user identify the key, including:

[0008] Step 1: Construct a set of stimulus signals, present them to users in pairs for subjective difference scoring, and obtain a comparative distance matrix for each pair of stimuli;

[0009] Step 2: Calculate the reduced 2D coordinate matrix of the stimulus using a multidimensional scaling algorithm. Obtain the representation of each stimulus in 2D space by comparing the distance matrix. The distance between each pair of stimuli in 2D space remains unchanged as the distance in the difference matrix, and draw a 2D coordinate diagram.

[0010] Step 3: When the stimuli in the two-dimensional image are evenly distributed, and there exists a set M of m stimuli, in which the sum of the differences between the stimulus pairs is the largest, and the distances between the stimulus pairs in the set are all greater than the standard deviation, then this set of stimuli is determined to be the stimulus set with the highest discriminability;

[0011] When there is no stimulus set that meets the conditions in the graph, a new stimulus signal is added to step one and compared with the existing stimulus, and steps two and three are repeated.

[0012] Preferably, in the step 1, the number of stimulus signals is n, and d is set. ij is the subjective difference score between stimuli i and j, and the comparative distance matrix D of each pair of stimuli is obtained as:

[0013]

[0014] Preferably, the step 2 includes:

[0015] A single stimulus is mapped into a two-dimensional coordinate matrix represented as zi = (z i1 ,z i2 ), the two-dimensional coordinate matrix Z of all n stimuli is:

[0016]

[0017] Let B be the inner product matrix after dimensionality reduction,

[0018] b ij is the sample z after dimensionality reduction i With z j The inner product of ij =z i1 *z j1 +z i2 *z j2 ,

[0019] The subjective difference score after dimensionality reduction is:

[0020] Preferably, the step 2 further comprises:

[0021] After calculation, the elements of the inner product matrix B after dimensionality reduction are:

[0022]

[0023] Perform eigenvalue decomposition on the inner product matrix B after dimensionality reduction, and obtain B=VAV T ;

[0024] Where A is a diagonal matrix and V is a matrix with eigenvectors as columns;

[0025] Set the A matrix to retain the first two largest eigenvalues and become The corresponding characteristic phasor V becomes The result after dimensionality reduction is:

[0026] Construct a reduced dimensional analysis two-dimensional space graph based on the Z two-dimensional space matrix.

[0027] Preferably, the step three includes:

[0028] Assume that the mutual distinguishability distance of a group of m stimuli is: Dis tan ce(M) = ∑ i,j∈M＝j d ij ;

[0029] Where M represents a combination of m stimuli.

[0030] Preferably, when light pressure is applied, the pressure sensor acquires a finger pressure less than or equal to 0.5N, and when heavy pressure is applied, the pressure sensor acquires a finger pressure greater than 0.5N.

[0031] Beneficial effects of the invention:

[0032] 1. This invention restores the tangibility of virtual buttons on the cockpit's intelligent touch surface. Unlike previous approaches that only used vibration to alert users to key input confirmation, this invention adds the ability to use tactile vibration to assist users in searching and identifying keys, enhancing the user interaction experience and reducing visual distractions during driving. Furthermore, requiring a certain amount of pressure to activate and deactivate functions prevents accidental touches.

[0033] 2. The design of intelligent touch interaction surfaces in cockpits is diverse. The size and number of virtual buttons, the electromechanical characteristics of motors with different tactile feedback, etc., will affect the user's tactile perception. The differential perception dimension of vibration tactile sensation felt by fingers is unknown, and the diversity of tactile waveform design may cause dimensionality disaster. This invention introduces a multidimensional scaling algorithm and proposes a method for creating distinguishable vibration signals in the same way for different numbers of virtual buttons. This can simplify the design process, rationally construct and select identifiable and different stimuli corresponding to different virtual buttons, and has strong portability. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram of the layout of the smart surface virtual keyboard described in the present invention.

[0035] Figure 2This is a flow chart of the tactile feedback described in the present invention.

[0036] Figure 3 This is a flow chart of the method for constructing a high-recognition-difference tactile signal for a virtual keyboard according to the present invention. DETAILED DESCRIPTION

[0037] The present invention will be described in further detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0038] like Figure 1-3 As shown, the present invention provides a tactile transmission method for identifying virtual keys on a cockpit smart surface. This method uses a smart surface virtual keyboard layout device to identify tactile presses. The smart surface virtual keyboard includes a pressure sensor 101 and a vibration element 100 disposed below the virtual keyboard. The smart surface is made of a translucent hard decorative material. An optoelectronic display with control logic is used to display virtual key icons. A pressure sensor 101 is disposed under each virtual key. The smart surface also includes a circuit layer for transmitting sensor signals and driving the vibration element 100.

[0039] The vibration element 100 is a piezoelectric element, a linear resonant motor, or an eccentric rotor motor. The pressure sensor 101 is a resistive flexible sensor. The pressure sensor 101 receives the keystrokes and pressure input by the user and transmits them to the corresponding control unit.

[0040] The control unit retrieves the target waveform parameters from the memory unit according to the user input key and the corresponding pressure;

[0041] A target driving signal is generated according to the target waveform parameters, and the target driving signal is sent to the vibration element 100 to drive the vibration element to vibrate the entire smart surface panel.

[0042] Among them, the pressing pressure is divided into light pressure and heavy pressure. Among them, in the present invention, as a preference, the dividing threshold between light pressure and heavy pressure is set to 0.5N, that is, light pressure is a pressure value below 0.5N, and heavy pressure is a pressure value greater than 0.5N.

[0043] When the user lightly presses any virtual key, the control unit calls the memory unit, provides the user with the tactile waveform corresponding to the current key, and outputs the waveform signal to drive the vibration source 100 through the circuit layer interface, without realizing the function of the current key. At this time, the user's pressing pressure is detected in real time. If the key is pressed lightly continuously, the tactile reminder of the current key is repeatedly output according to the interval period; if the user further presses it hard at this time, the function of the current key is realized, and the tactile vibration feedback of the successful response is output in sequence.

[0044] Among them, the tactile waveform during heavy pressure is a vibration signal or a simple short wave that simulates the start and stop of a real physical button; the specific waveform during light pressure needs to be constructed according to a tactile transmission method for identifying virtual buttons on the intelligent surface of the cockpit provided by the present invention. Since the size, number, electromechanical characteristics and load of the virtual buttons on an operating area are not fixed and will affect the user's perception characteristics, the selection of multiple vibration parameters will lead to a dimensional explosion. There are m virtual buttons on the intelligent interactive surface panel. In order to provide unique tactile stimulation to help users identify buttons when lightly pressed, a method is proposed to extract m highly distinguishable stimulation signals using a multi-dimensional scaling algorithm.

[0045] The starting point of the multi-dimensional scaling method is to keep the distance between various points in the original data space unchanged as much as possible in the two-dimensional space. The selection of vibration reminders corresponding to m virtual keys in the present invention needs to be combined with the subjective perception of vibration tactile sensation of human fingers. It is necessary to select m stimulus signals with large differences from each other and use a multi-dimensional scaling algorithm to calculate and select them, including:

[0046] The pressure sensor captures the pressure of pressing the virtual key. When the virtual key is pressed hard, it responds normally to the finger. When the virtual key is pressed lightly, it is recognized and responded to through tactile transmission methods, including:

[0047] The pressure sensor captures the pressure of pressing the virtual key. When the virtual key is pressed hard, it responds normally to the finger. When the virtual key is pressed lightly, it is recognized and responded to through tactile transmission methods, including:

[0048] Step 1: Construct a set of stimulus signals, present them to users in pairs for subjective difference scoring, and obtain a comparative distance matrix for each pair of stimuli;

[0049] Among them, according to the sampling period and the electromechanical characteristics of the vibration element, a set of stimulation signals, n in total, are constructed by changing the frequency, amplitude, waveform, and amplitude modulation parameters;

[0050] Set d ij is the subjective difference score between stimuli i and j, and the comparative distance matrix D of each pair of stimuli is obtained as:

[0051]

[0052] Step 2: Calculate the reduced 2D coordinate matrix of the stimulus using a multidimensional scaling algorithm. Obtain the representation of each stimulus in 2D space by comparing the distance matrix. The distance between each pair of stimuli in 2D space remains unchanged as the distance in the difference matrix, and draw a 2D coordinate diagram.

[0053] Assume that a single stimulus map is a two-dimensional coordinate matrix represented as zi = (z i1 ,z i2), the two-dimensional coordinate matrix Z of all n stimuli is:

[0054]

[0055] Let B be the inner product matrix after dimensionality reduction,

[0056] Where b ij is the sample z after dimensionality reduction i With z j The inner product of ij =z i1 *z j1 +z i2 *z j2 ,

[0057] The subjective difference score after dimensionality reduction is:

[0058] After calculation, the elements of the inner product matrix B after dimensionality reduction are:

[0059]

[0060] Perform eigenvalue decomposition on the inner product matrix B after dimensionality reduction, and obtain B=VAV T

[0061] Where A is a diagonal matrix and V is a matrix with eigenvectors as columns;

[0062] Set the A matrix to retain the first two largest eigenvalues and become The corresponding characteristic phasor V becomes The result after dimensionality reduction is:

[0063] Construct a reduced dimensional analysis two-dimensional space graph based on the Z two-dimensional space matrix.

[0064] The dimensionality reduction graph intuitively reflects the Euclidean distance between all stimulus pairs in two-dimensional space. The mutual distinguishability distance of a group of m stimuli is set as: Distance = ∑d ij .

[0065] Step 3: When there is a set M of m stimuli in the two-dimensional graph, and the distances between each stimulus pair in the set are greater than the standard deviation, and the sum of the distances between all stimulus pairs is the largest, then this set of stimuli is determined to be the stimulus set with the highest discriminability;

[0066] When there is no stimulus set that meets the conditions in the graph, a new stimulus signal is added to step one and compared with the existing stimulus, and steps two and three are repeated.

[0067] If the dimensionality reduction graph shows that the stimuli are evenly dispersed, and a group of m stimuli can be found with the largest distance, and the perceptual distance between each stimulus pair is greater than the standard deviation of the distance in the Euclidean distance matrix, then this group of signals is determined as the stimulus set with the largest perceptual difference;

[0068] If the above conditions cannot be met, it means that the original vibration parameter selection is biased or the data set has too few stimuli. Based on the dimensionality reduction space diagram, some similar stimuli with similar distances are proposed, and the added stimuli are compared with the retained stimuli to obtain the distance matrix, and steps 2 and 3 are repeated.

[0069] Finally, a set of m stimulus signals with large perceptual differences between each other is finalized and stored in the memory unit corresponding to the corresponding interactive surface. Each virtual button corresponds to a different stimulus signal.

[0070] That is, m stimuli constitute a set M, and their difference scores are added together: Distance(M) = ∑ i,j∈M＝j d ij , is the largest among any m stimulus combinations, and in order to prevent any pair of stimuli from being too similar, the perceived difference score of any pair of stimuli is greater than the standard deviation of the comparison distance matrix, then the set M is determined to be the m stimulus set with the highest discriminability tactile signals.

[0071] The present invention arranges pressure sensors under each virtual button on the smart surface to obtain the force applied by the user on the virtual button in real time. When the user is only touching, the corresponding tactile signal is called according to the corresponding button position of the user's finger, and the signal is output to the motor that provides vibration tactile sensation, thereby providing a unique normal vibration to the user's finger to help the user identify the button position and the corresponding button function. When the input pressure is greater than 0.5N, it indicates that the user is aware of his current operation, and only ordinary tactile feedback is provided to notify the start and stop status of the corresponding function. In order to ensure the identifiable and distinguishable nature of each virtual button, the present invention provides a method for constructing a set of highly identifiable stimulus sets using a multi-dimensional scaling algorithm. Therefore, when the finger moves on the interactive surface, the position of the virtual button and the corresponding button function can be sensed through unique vibration. At the same time, setting the pressure threshold to start and stop the function can also prevent accidental touches.

[0072] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A tactile transmission method for identifying virtual buttons on a cockpit smart surface, characterized in that: include: The pressure sensor detects the pressure applied to the virtual key. When pressed hard, the virtual key responds normally to the finger, reminding the user that the operation was successful. When pressed lightly, tactile transmission methods are used to help the user identify the key, including: Step 1: Construct a set of stimulus signals, present them to users in pairs for subjective difference scoring, and obtain a comparative distance matrix for each pair of stimuli; The constructing of a set of stimulation signals is , set For stimulation and The subjective difference scores of each pair of stimuli are obtained by comparing the distance matrix for: ； Step 2: Calculate the reduced 2D coordinate matrix of the stimulus using a multidimensional scaling algorithm. Obtain the representation of each stimulus in 2D space by comparing the distance matrix. The distance between each pair of stimuli in 2D space remains unchanged as the distance in the difference matrix, and draw a 2D coordinate diagram. A single stimulus is mapped into a two-dimensional coordinate matrix represented as ,all Stimulus 2D coordinate matrix for: ； set up is the inner product matrix after dimensionality reduction, ; is the sample after dimensionality reduction and The inner product of , The subjective difference score after dimensionality reduction is: ; The inner product matrix after dimensionality reduction is calculated The elements are: ； For the inner product matrix after dimensionality reduction Perform eigenvalue decomposition and get ; Where, is a diagonal matrix, is a matrix with eigenvectors as columns; set up The matrix retains the first two largest eigenvalues and becomes , the corresponding characteristic phasor becomes , and get the result after dimensionality reduction: , according to The two-dimensional space matrix constructs the analytical two-dimensional space graph after dimensionality reduction; Step 3: When the stimuli in the two-dimensional image are evenly distributed, there is a group of A stimulating collection , where the sum of the differences between each stimulus pair is the largest, and the distances between each stimulus pair in the set are all greater than the standard deviation, then this set of stimuli is determined to be the stimulus set with the highest discriminability; When there is no stimulus set that meets the conditions in the graph, a new stimulus signal is added to step one and compared with the existing stimulus, and steps two and three are repeated.

2. The tactile transmission method for identifying virtual buttons on a cockpit smart surface according to claim 1, characterized in that: The step three includes: Set a group The mutual distinguishability distance of the stimuli is: ; Where, Indicates containing A stimulating combination.

3. The tactile transmission method for identifying virtual buttons on a cockpit smart surface according to claim 1, characterized in that: When light pressure is applied, the pressure sensor obtains a finger pressure less than or equal to 0.5N. When heavy pressure is applied, the pressure sensor obtains a finger pressure greater than 0.5N.

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