Basic stroke training and evaluating device for soft pen calligraphy

Abstract

The invention provides a soft pen calligraphy basic stroke training evaluation device, and belongs to the technical field of behavior operation automatic evaluation. The technical problem that a device capable of monitoring and evaluating the standardization and accuracy of soft pen calligraphy basic stroke writing in real time is lacked is solved. The method comprises the following steps that standard writing and common wrong writing in the soft pen calligraphy basic stroke writing process are analyzed; the method comprises the following steps: acquiring sensor data of standard writing and common wrong writing in a basic stroke writing process through a sensor array module, performing feature extraction on the data acquired by a sensor, and establishing a stroke starting operation training evaluation model, a stroke running operation training evaluation model and a stroke receiving operation training evaluation model by utilizing the sensor feature data; the basic stroke writing process of a writer is trained and evaluated according to the writing starting operation training evaluation model, the writing running operation training evaluation model and the writing stopping operation training evaluation model, a standard conclusion is given according to writing standards, and a non-standard writing conclusion, corresponding reasons and suggestions are given according to non-standard writing. The method is applied to the automatic training evaluation of the basic stroke writing of the soft pen calligraphy.

Description

Technical Field

[0001] The invention provides a basic stroke training and evaluation device for soft brush calligraphy, belonging to the technical field of automatic training and evaluation of behavioral operations. Background Art

[0002] The basic stroke training of soft brush calligraphy is not only a skill training, but also a comprehensive cultivation of the mind, aesthetics, culture and spirit. It is the only way for calligraphy learners to enter a higher level of creation and expression, and it is also an important way to inherit and promote Chinese traditional culture. The training of the basic strokes of soft brush calligraphy, such as starting, moving and ending, is an indispensable part of calligraphy learning. Through repeated practice, the calligrapher can not only improve his technical level, but also better express his personal style and enhance his deep understanding of the art of calligraphy.

[0003] In soft brush calligraphy, the training of starting, moving and ending basic strokes is the core content, but there are often some difficulties in traditional training. When starting a stroke, the force of the pen tip needs to be accurately controlled to ensure that the line at the beginning of the stroke is full and stable. Beginners often cannot grasp the appropriate force, resulting in the stroke being too light or too heavy, affecting the overall effect; different starting methods require the writer to accurately control the angle of the pen tip, and beginners often find it difficult to perceive and maintain the correct angle, resulting in the beginning of the stroke being less than ideal. During the writing process, the pen tip needs to apply force evenly to ensure the continuity and consistency of the line; the writing needs to maintain a certain speed, and the direction of the pen tip needs to be adjusted as the shape of the character changes. Beginners are prone to problems such as too fast or too slow speed and direction deviation when writing, which affects the beauty of the character shape. In traditional training, it is difficult for writers to accurately perceive and maintain the changes in force during the writing process, and it is easy to have problems such as broken pen and trembling pen. When finishing a stroke, you need to control the force to form a natural finishing effect. In traditional training, beginners often find it difficult to master this force change, resulting in a too stiff or weak finishing stroke. Different finishing methods have different requirements for the direction of the pen tip. In traditional training, beginners are prone to unnatural finishing strokes due to inaccurate direction control. Therefore, there is a great need for a technology that can monitor and evaluate the standardization and accuracy of the basic strokes of soft brush calligraphy in real time, so as to effectively improve the writing skills of the writer and improve the efficiency of writing learning. Summary of the invention

[0004] In order to solve the technical problem that the standardization and accuracy of the basic strokes of soft-brush calligraphy written by the writer cannot be monitored and evaluated in real time, the present invention proposes a basic strokes training and evaluation device for soft-brush calligraphy.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a soft brush calligraphy basic stroke training and evaluation device, including a pressure sensor array module, a data acquisition module, a wireless transmission module and a host computer; the pressure sensor array module is a capacitive touch sensor array, which is used to collect the writing force and position changes of the writer during the writing process; the data acquisition module uses a multi-channel analog-to-digital converter and a microcontroller to collect data, and the real-time pressure data of the pressure sensor array module is read by the microcontroller; the wireless transmission module transmits the real-time pressure data collected by the data acquisition module to the host computer; The pressure data is transmitted to the host computer, which analyzes and processes the real-time pressure data, evaluates the writer's basic stroke writing process and gives feedback; the host computer is provided with a pen-starting operation training evaluation model, a pen-traveling operation training evaluation model and a pen-ending operation training evaluation model, wherein the pen-starting operation training evaluation model includes training evaluation of pen-starting with the tip of the brush in reverse, pen-starting with the tip of the brush exposed and pen-starting with the tip of the brush hidden; the pen-traveling operation training evaluation model includes training evaluation of pen-traveling with the tip of the brush in the middle, pen-traveling with the tip of the brush sideways and pen-lifting and pressing; the pen-ending operation training evaluation model includes training evaluation of pen-ending with the tip of the brush in reverse, pen-ending with the tip of the brush exposed and pen-ending with the tip of the brush hidden.

[0006] The present invention can effectively solve the problems existing in the prior art and improve the training effect by taking advantage of the advantages of sensor technology. The device enables the writer to master calligraphy skills faster and more accurately through real-time force feedback, angle calibration, speed control and automated evaluation. This technology not only improves the training efficiency, but also helps beginners better understand and apply the basic essentials of calligraphy, providing a more scientific and efficient way for calligraphy learning.

[0007] Furthermore, the device adopts a soft brush calligraphy basic stroke training and evaluation method to realize soft brush calligraphy basic stroke writing training and evaluation; the soft brush calligraphy basic stroke training and evaluation method comprises the following steps: step one, analyzing the standard writing and common incorrect writing in the writing process of starting, running and ending of the basic strokes of soft brush calligraphy, the starting methods include reverse tip starting, exposed tip starting and hidden tip starting, the standard writing of reverse tip starting is moderate reverse tip starting force, correct reverse tip starting writing direction and natural turning tip, the common incorrect writing is reverse tip starting force The pen tip is too large or too small, the angle of the pen tip is wrong, and the pen tip is unnatural; the standard writing of the exposed tip is moderate in force, correct in writing direction, and steady in the exposed tip. Common mistakes are too large or too small in force, wrong in writing angle, and unstable in the exposed tip. The standard writing of the hidden tip is accurate in speed and uniform in force, and common mistakes are uneven force, too fast or too slow in speed; the writing methods include center-point writing, side-point writing, and lifting-point writing. The standard writing style of center-point writing is that the tip of the pen is located in the middle of the stroke, and the writing force is uniform. Common mistakes are that the tip of the pen deviates from the center line and the writing force is uneven. The standard writing style of side-point writing is that the tip of the pen is appropriately offset and the writing force changes naturally. Common mistakes are that the tip of the pen is excessively or insufficiently offset and the writing force changes unnaturally. The standard writing style of lifting and pressing is that the lifting and pressing force is uniform and the lifting and pressing rhythm is accurate during the writing process. Common mistakes are that the lifting and pressing force is improperly controlled and the lifting and pressing rhythm is uneven. The methods of finishing the stroke include returning the tip of the pen to finish the stroke, and extending the tip of the pen to finish the stroke. The standard writing of the ending stroke and the ending stroke with hidden tip is that the writing force of the ending stroke is moderate and the ending angle of the ending stroke is correct. Common mistakes are that the writing force of the ending stroke is too large or too small and the ending angle of the ending stroke is incorrect; the standard writing of the ending stroke with the tip is that the writing force of the ending stroke is uniform and the ending angle of the ending stroke is correct. Common mistakes are that the writing force of the ending stroke is uneven and the ending angle of the ending stroke is incorrect; the standard writing of the ending stroke with hidden tip is that the writing force of the ending stroke is uniform and the ending speed of the ending stroke is accurate. Common mistakes are that the writing force of the ending stroke is uneven and the ending speed of the ending stroke is inappropriate; Step 2: The pressure sensor array module is used to collect the pressure sensor data of the standard writing and common incorrect writing of the basic strokes of soft brush calligraphy, and the pressure sensor array arranged in the form of an N´N matrix is ​​embedded under the writing surface to measure the pressure applied to the writing surface during writing. The analog signal of the pressure sensor is converted into a digital signal using a multi-channel analog-to-digital converter (ADC) and a microcontroller, and the pressure sensor array data and the collection time collected by the data collection module are transmitted to the host computer through the wireless transmission module; Step 3: The host computer establishes an N×N matrix writing position area according to the installation position of the pressure sensor array in a 1:1 ratio, which corresponds to the pressure sensor array arranged in the N×N matrix form on the writing surface one by one, and stores the data collected by the pressure sensor array in the rectangular writing position area corresponding to each sensor, and records the collection time at the same time; the host computer uses the Kalman filter algorithm to smooth the data collected by the pressure sensor array to eliminate the influence of noise, and extracts features from the data after noise elimination to obtain sensor feature data of standard writing and common erroneous writing, and then uses the sensor feature data to establish a pen-starting operation training evaluation model, a pen-travel operation training evaluation model, and a pen-ending operation training evaluation model; Step 4: Evaluate the entire writing process of the writer based on the pen-starting operation training evaluation model, the pen-travel operation training evaluation model and the pen-ending operation training evaluation model to determine whether the writer's writing is standard. If the writing is standard, give a standard conclusion; if the writing is not standard, give a specific name, corresponding reasons and suggestions.

[0008] In step 3, the pressure sensor array is an N×N matrix, denoted as P(t), where each element p i,j (t) represents the pressure value of the pressure sensor in the i-th row and j-th column of the pressure sensor array at time t. Assume that the writing position area of ​​the host computer matrix is ​​also an N×N matrix, denoted as R, where each element r(i,j,t) represents the pressure value of the sensor in the i-th row and j-th column at time point t, and the upper left corner of the matrix is ​​specified as the starting origin.

[0009] In the step three, the host computer extracts features from the data collected by the pressure sensor array to obtain sensor feature data for standard writing and common incorrect writing, wherein the sensor feature data for standard writing and common incorrect writing include the pressure value during standard writing, the standard deviation of the pressure value, the writing path direction, the rate of change of the writing path direction, the smoothness of the writing pressure change, the writing speed, the centerline offset, and the pen tip offset; the host computer plots the indication r(i, j, t) of the pressure sensor during the writer's standard writing into a pressure curve, finds the peak TFR of the pressure curve, which is the upper limit of the force of the writer's standard writing, finds the trough TGR of the curve, which is the lower limit of the force of the writer's standard writing, takes the maximum value of the force TFR of the standard writing of all operators as the upper limit of the interval, and takes the minimum value TGR as the lower limit of the interval, that is, the pressure sensor force value interval is [min{TGR}, max{TFR}], which is used as a basis for judging whether the writing force is appropriate; for each time point t, extracts the maximum pressure value Rm(t) of the pressure sensor array, and calculates the standard deviation σ of the pressure value during the writing process. R , , is the mean of the maximum pressure value time series; by analyzing the changes in pressure data, the writing path direction is determined, and for each time point t, the maximum position A(i t , j t ), calculate the path direction at each time point t, that is, the direction d from time point t−1 to t t , d t =arctan((j t -j t-1 ) / (i t -i t-1 ) ; Calculate the rate of change of the path direction dd, that is, calculate d t With d t-1 The difference dd is used to indicate the rate of change of the writing path direction; t Determine the direction of the writing path. For each time point t, extract the maximum pressure value Rm(t) of the pressure sensor array and calculate the gradient G(t) of the pressure time series, that is, the pressure change between adjacent time points. G(t)=Rm(t+1)−Rm(t). For t=1,2,…,T−1, calculate the absolute value of the pressure gradient |G(t)| and take the average value Smean to evaluate the smoothness of the writing pressure change. |G(t)|=abs(G(t)), where abs is the absolute value operation. ; The writing speed is calculated by analyzing the time series of the pressure sensor data to calculate the writing speed v(t) during the writing process; the trajectory of the maximum pressure point in the pressure sensor array at each time point in the writing process is recorded to form a path, P(t)=(i t ,j t ), where i t and j t are the row and column coordinates of the pressure sensor array, respectively. Assuming that the ideal midline position is a fixed row or column, such as i c or c , then the deviation of the pen tip from the center line can be expressed as Δc(t)=abs(j t −j c ) or Δc(t)=abs(i t −i c ), calculate the mean value mean(Δc) of the offset Δc(t) from each point in the path to the center line, which is used to represent the center line offset; calculate the actual offset Δside(t) of the pen tip relative to the ideal side tip trajectory. Assuming that the ideal side tip trajectory is parallel to a certain center line and has a fixed offset di, then Δside(t)=abs((j t −j c )−di), calculate the mean value mean(Δs) of the offset, which is used to represent the pen tip offset.

[0010] In the step 3, the sensor characteristic data is used to establish a pen-starting operation training and evaluation model; the standard writing of the reverse-tip pen-starting is moderate reverse-tip pen-starting force, correct reverse-tip pen-starting direction and natural turning of the pen tip, wherein the correct reverse-tip pen-starting direction means that the pen tip first gently hooks back against the direction of the stroke, and then turns to the positive direction of the pen, and common incorrect writing is that the reverse-tip pen-starting force is too large or too small, the reverse-tip pen-starting angle is incorrect and the turning of the pen tip is unnatural; the pressure sensor data when the reverse-tip pen-starting is analyzed and features are extracted, and the extracted features include the pressure value when the reverse-tip pen-starting is written, the writing path direction and the writing path direction change rate; the standard writing force value interval [min{TGR}, max{TFR}] when the reverse-tip pen-starting is extracted as a basis for judging whether the reverse-tip pen-starting force is moderate. When the writer writes, the pressure sensor value is within this interval, indicating that the reverse-tip pen-starting force is moderate, exceeding max{TFR}, indicating that the reverse-tip pen-starting force is too large, and below min{TGR}, indicating that the reverse-tip pen-starting force is too small; calculate the reverse-tip pen-starting time d t If the value is negative first and then positive, it means that the writing direction of the reverse pen is correct. Otherwise, it means that the reverse pen angle is incorrect. The direction change rate of the writing path when the reverse pen is started is extracted, that is, d t With d t-1 The difference dd is calculated. If dd is less than the set threshold value Td, the turning of the pen tip is natural, otherwise the turning of the pen tip is unnatural. Td is the maximum value obtained when writing in a standard way. The standard writing of the pen tip starting with a pen tip is as follows: the pen tip starting with a moderate force, the writing direction of the pen tip starting with a pen tip is correct, and the pen tip is stable when writing in a standard way. The correct writing direction of the pen tip starting with a pen tip is that the pen tip moves directly in the direction of the stroke. Common incorrect writing is that the pen tip starting with a force that is too large or too small, the pen tip starting with a wrong angle, and the pen tip is unstable when writing in a standard way. The pressure sensor data when writing in a standard way is analyzed and features are extracted to provide a method for The features include the pressure value when writing with the tip exposed, the direction of the writing path and the smoothness of the writing pressure change, and the force value interval [min{TGR}, max{TFR}] of the standard writing when the tip is exposed is extracted as the basis for judging whether the force of the pen is moderate. When the writer writes, the pressure sensor value is within this interval, indicating that the force of the pen is moderate. When it exceeds max{TFR}, it indicates that the force of the pen is too large. When it is lower than min{TGR}, it indicates that the force of the pen is too small. Calculate the different moments d when the tip is exposed. tThe value is always positive, indicating that the writing direction of the pen tip is correct and the pen tip moves directly in the direction of the stroke. Otherwise, it indicates that the angle is wrong when the pen tip is started. Calculate G(t), |G(t)| and Smean when the pen tip is started. If |G(t)| is less than the set threshold TGl and Smean is less than the set threshold TSl, the pen tip is stable when the pen tip is started. Otherwise, it indicates that the pen tip is unstable when the pen tip is started. TGl is the maximum value of |G(t)| when the pen tip is written in a standard way. TSl is the maximum value of Smean obtained when writing with the tip of the pen exposed; standard writing with the tip of the pen hidden means that the speed of the pen is accurate and the force is uniform when the pen is hidden. The uniform force when the pen is hidden means that the tip of the pen touches the paper lightly and the force is applied slowly so that the tip of the pen is completely hidden in the stroke. Common errors are uneven force when the pen is hidden and the speed of the pen is too fast or too slow. The pressure sensor data when the pen is hidden is analyzed and features are extracted. The extracted features include the pressure standard deviation σ when the pen is hidden. R and writing speed v(t), calculate the standard deviation of pressure σ when starting to write with the tip of the pen hidden R , if σ R If it is less than the set threshold value Tcq, the force is uniform when the pen is hidden, otherwise it indicates that the force is uneven when the pen is hidden. Tcq is the standard writing time of the pen hidden. R The maximum value obtained; calculate the writing speed v(t) when the pen is started with the tip of the pen hidden. If v(t) is in the speed range [vcqmin,vcqmax], it means that the speed of starting with the tip of the pen is accurate. If it exceeds vcqmax, it means that the speed of starting with the tip of the pen is too fast. If it is less than vcqmin, it means that the speed of starting with the tip of the pen is too slow. vcqmin is the minimum speed when the pen is started with the tip of the pen hidden, and vcqmax is the maximum speed when the pen is started with the tip of the pen hidden.

[0011] In the step three, the sensor feature data is used to establish a pen operation training and evaluation model; the standard writing of the center-point pen is that the pen tip is located in the middle of the stroke, and the writing force is uniform. The uniform writing force means that the pen shaft is kept vertical or nearly vertical to the paper surface when writing. Common writing errors are the pen tip deviating from the center line and the writing force is uneven. The pressure sensor data when the center-point pen is written is analyzed and features are extracted. The extracted features include the center line offset when the center-point pen is written and the smoothness of the writing pressure change; the center line offset mean (Δc) is calculated. If mean (Δc) is less than the set threshold value Tc, the center-point pen tip is located in the middle of the stroke. In the middle, the pen tip does not deviate from the center line, otherwise the pen tip deviates from the center line, and Tc is the threshold for deviation from the center line when writing in a standard manner; calculate G(t), |G(t)| and Smean when writing with the center tip of the pen. If |G(t)| is less than the set threshold TGz and Smean is less than the set threshold TSz, it indicates that the writing force is uniform, otherwise it indicates that the writing force is uneven. TGz is the maximum value of |G(t)| when writing with the center tip of the pen in a standard manner, and TSz is the maximum value of Smean when writing with the center tip of the pen in a standard manner; standard writing with a side tip of the pen means that the pen tip deviates appropriately and the writing force changes naturally. Appropriate pen tip deviation means that the pen tip deviates to one side. When writing with the side tip, the pen is slightly tilted. Common writing errors include excessive or insufficient deviation of the pen tip and unnatural changes in writing force. The pressure sensor data when writing with the side tip is analyzed and features are extracted. The extracted features include the pen tip deviation mean (Δs) and the smoothness of the writing pressure change. If the pen tip deviation mean (Δs) does not exceed the threshold TSS, it indicates that the pen tip deviation is appropriate, otherwise it indicates that the pen tip deviation is excessive or insufficient. Calculate G(t), |G(t)| and Smean when writing with the side tip. If |G(t)| is less than the set threshold TGc and Smean is less than the set threshold TSc, then The force of writing with a side-edge pen changes naturally, otherwise it means that the force of writing with a side-edge pen changes unnaturally. TGc is the maximum value obtained by |G(t)| when writing with a side-edge pen in a standard manner, and TSc is the maximum value obtained by Smean when writing with a side-edge pen in a standard manner. Standard writing of lifting and pressing means that the force of lifting and pressing is uniform and the rhythm of lifting and pressing is accurate during the writing process. Accurate rhythm of lifting and pressing means that the lifting and pressing of the pen are changed according to the needs. Common errors in writing are improper control of the force of lifting and pressing and uneven rhythm of lifting and pressing. The pressure sensor data during lifting and pressing is analyzed and features are extracted. The extracted features include the pressure standard deviation σ during lifting and pressing writing R and writing speed v(t), calculate the standard deviation of pressure when writing with the pen lifted and pressed σ R , if σ R If it is less than the set threshold value TTA, the lifting and pressing force of the pen is uniform, otherwise it indicates that the lifting and pressing force of the pen is improperly controlled. TTA is the standard writing time of lifting and pressing the pen. RThe maximum value obtained; calculate the writing speed v(t) when lifting and pressing the pen. If v(t) is within the speed range [vtamin,vtamax], it indicates that the rhythm of lifting and pressing the pen is accurate, otherwise it indicates that the rhythm of lifting and pressing the pen is uneven. vtamin is the minimum speed when lifting and pressing the pen in a standard way, and vtamax is the maximum speed when lifting and pressing the pen in a standard way.

[0012] In the step three, the sensor characteristic data is used to establish a training and evaluation model for the finishing operation; the standard writing of the back-tip finishing stroke is that the writing force of the back-tip finishing stroke is moderate and the back-tip finishing angle is correct, the correct back-tip finishing angle means that the pen tip rotates smoothly to finish the stroke, and common incorrect writing is that the back-tip finishing force is too large or too small and the back-tip finishing angle is incorrect. The pressure sensor data when the back-tip finishing stroke is analyzed and features are extracted. The extracted features include the pressure value and the writing path direction during standard writing. The force value interval [min{TGR}, max{TFR}] of the standard writing when the back-tip finishing stroke is extracted as a basis for judging whether the back-tip finishing force is moderate. When the writer writes, the pressure sensor value is within this interval, indicating that the back-tip finishing force is moderate. When it exceeds max{TFR}, it indicates that the back-tip finishing force is too large. When it is lower than min{TGR}, it indicates that the back-tip finishing force is too small. Calculate the back-tip finishing stroke at different times d t The value satisfies the condition that the positive value is first followed by the negative value, indicating that the angle of the back-stroke is correct, otherwise it indicates that the angle of the back-stroke is incorrect; the standard writing of the tip-out pen is that the tip-out pen force is uniform and the tip-out pen angle is correct. The correct tip-out pen angle means that the tip of the pen quickly extends outward to form a sharp pen ending effect. Common errors in writing are uneven tip-out pen force and incorrect tip-out pen angle. The pressure sensor data during the tip-out pen is analyzed and features are extracted. The extracted features include the smoothness of the change in writing pressure and the direction of the writing path. G(t), |G(t)| and Smean during the tip-out pen writing are calculated. If |G(t)| is less than the set threshold TGch and Smean is less than the set threshold TSch, it indicates that the tip-out pen force is uniform, otherwise it indicates that the tip-out pen force is uneven. TGch is the maximum value obtained by |G(t)| when the tip-out pen is written in a standard way, and TSch is the maximum value obtained by Smean when the tip-out pen is written in a standard way; the tip-out pen at different times d is calculated tThe value is always positive, indicating that the angle of the pen tip is correct, otherwise it indicates that the angle of the pen tip is incorrect; the standard writing of the hidden pen tip is that the force of the hidden pen tip is uniform and the speed of the hidden pen tip is accurate. The uniform force of the hidden pen tip means that the pen tip is gently retracted and gradually lifted. Common errors in writing are uneven force and inappropriate speed of the hidden pen tip. The pressure sensor data when the hidden pen tip is closed is analyzed and features are extracted. The extracted features include the smoothness of the writing pressure change and the writing speed when the hidden pen tip is closed. G(t), |G(t)| and Smean when writing when the hidden pen tip is closed are calculated. If |G(t)| is less than the set threshold TGca and Smean is less than the set threshold TSca, If v(t) is within the speed range [vcamin,vcamax], it indicates that the speed is accurate; if it exceeds vcamax, it indicates that the speed is too fast; if it is less than vcamin, it indicates that the speed is too slow, it indicates that the speed is inappropriate; vcamin is the minimum speed when the writing is in accordance with the standard; vcamax is the maximum speed when the writing is in accordance with the standard.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention applies modern sensor technology to the training of basic strokes of soft brush calligraphy, extracts sensor feature data of standard writing and common incorrect writing in the starting, running and ending of basic strokes of soft brush calligraphy by analyzing the standard writing and common incorrect writing, and uses the sensor feature data to establish a training and evaluation model for starting operation, a training and evaluation model for running operation and a training and evaluation model for ending operation, so as to monitor and evaluate the standardization and accuracy of the basic stroke writing of the writer in real time and provide personalized operation feedback and improvement suggestions, quantify each writing action, and provide instant feedback. Through the real-time feedback and guidance of the sensor, the learner can master the basic essentials of calligraphy more quickly, thereby lowering the learning threshold, helping beginners to better understand and apply the basic essentials of calligraphy, and providing a more scientific and efficient way for calligraphy learning. DETAILED DESCRIPTION

[0014] The present invention is further described below by taking the writing operation of the basic strokes of soft brush calligraphy, namely, horizontal stroke, left stroke, right stroke and vertical hook as an example. For other basic strokes of soft brush calligraphy, there are similar evaluation processes as described below.

[0015] The writing process of the basic strokes of soft brush calligraphy includes starting, moving and ending. The starting methods include starting with the tip of the brush, starting with the tip of the brush exposed and starting with the tip of the brush hidden. The moving methods include moving with the center of the brush, moving with the side of the brush and moving with lifting and pressing. The ending methods include ending with the tip of the brush back, ending with the tip of the brush exposed and ending with the tip of the brush hidden. The requirements for the basic horizontal strokes are as follows: starting with the tip of the brush back, moving with the center of the brush and ending with the tip of the brush exposed; the requirements for the basic left-falling strokes are as follows: starting with the tip of the brush exposed, moving with the side of the brush and ending with the tip of the brush exposed; the requirements for the basic right-falling strokes are as follows: starting with the tip of the brush hidden, moving with the side of the brush and ending with the tip of the brush back; the requirements for the basic vertical hook strokes are as follows: starting with the tip of the brush back, moving with lifting and pressing and ending with the tip of the brush hidden. The specific implementation steps are as follows: Step 1: Analyze the standard writing and typical incorrect writing in the process of starting, moving and ending the basic strokes of soft brush calligraphy. The methods of starting a stroke include starting with the tip of the brush, starting with the tip of the brush exposed and starting with the tip of the brush hidden. The standard writing of starting with the tip of the brush is moderate in strength, correct in writing direction and natural in turning the tip of the brush. The correct direction of starting with the tip of the brush means that the tip of the brush first gently hooks back against the direction of the stroke, and then turns to move in the positive direction. Common incorrect writing is that the strength of the starting stroke of the brush is too large or too small, the angle of the starting stroke is incorrect and the turning of the tip of the brush is unnatural; the standard writing of starting with the tip of the brush exposed is exposed. The force when starting to write with the tip of the pen is moderate, the writing direction when the tip of the pen is exposed is correct, and the pen tip is steady when starting to write with the tip of the pen exposed. The correct writing direction when starting to write with the tip of the pen exposed means that the pen tip moves directly in the direction of the stroke. Common writing errors include too much or too little force when starting to write with the tip of the pen exposed, wrong angle when starting to write with the tip of the pen exposed, and unstable pen tip when starting to write with the tip of the pen exposed. Standard writing when starting to write with the tip of the pen hidden is accurate in the speed of starting to write with the tip of the pen hidden and uniform force when starting to write. Uniform force when starting to write with the tip of the pen hidden means that the tip of the pen lightly touches the paper surface, and force is slowly applied so that the pen tip is completely hidden in the stroke. Common errors include uneven force when starting to write with the tip of the pen hidden and too fast or too slow in the speed of starting to write with the tip of the pen hidden. The writing methods include center-point writing, side-point writing and lift-and-press writing. The standard writing method of center-point writing is that the pen tip is located in the middle of the stroke and the writing force is even. Even writing force means keeping the pen shaft vertical or nearly vertical to the paper surface when writing. Common writing errors are the pen tip deviating from the center line and uneven writing force; the standard writing method of side-point writing is that the pen tip is appropriately offset and the writing force changes naturally. Appropriate offset of the pen tip means that the pen tip is biased to one side and the pen shaft is slightly tilted when writing. Common writing errors are excessive or insufficient offset of the pen tip and unnatural writing force changes; the standard writing method of lift-and-press writing is that the lifting and pressing force is even and the lifting and pressing rhythm is accurate during the writing process. Accurate lifting and pressing rhythm means that the lifting and pressing of the pen are changed according to needs. Common writing errors are improper control of lifting and pressing force and uneven lifting and pressing rhythm. The methods of finishing a stroke include ending with a return tip, ending with an outward tip and ending with a hidden tip. The standard writing of ending with a return tip is that the writing force of the return tip is moderate and the writing angle of the return tip is correct. The correct angle of ending with a return tip means that the tip of the pen turns back and finishes the stroke smoothly. Common writing errors are that the force of the return tip is too large or too small and the angle of the return tip is incorrect; the standard writing of ending with an outward tip is that the force of the outward tip is uniform and the angle of the outward tip is correct. The correct angle of ending with an outward tip means that the tip of the pen quickly extends outward to form a sharp finishing effect. Common writing errors are uneven force of the outward tip and incorrect angle of the outward tip; the standard writing of ending with a hidden tip is that the force of the hidden tip is uniform and the speed of the hidden tip is accurate. The uniform force of the hidden tip means that the tip of the pen is gently retracted and gradually lifted up. Common writing errors are uneven force of the hidden tip and inappropriate speed of the hidden tip.

[0016] Step 2: Build a sensor array data acquisition and transmission module, collect sensor data of standard writing and common incorrect writing of basic strokes of soft brush calligraphy through the pressure sensor array module, embed an N×N rectangular pressure sensor array under the writing surface, measure the pressure applied to the surface during writing, use a multi-channel ADC and a microcontroller to convert analog sensor signals into digital signals, and transmit the pressure sensor array data and acquisition time collected by the data acquisition module to the host computer through the wireless transmission module; Step 3: Through the pressure sensor array data acquisition and transmission module built in the second step, the writer performs standard writing of basic strokes of soft brush calligraphy and common errors, and the pressure sensor array collects standard writing and common errors of basic strokes of soft brush calligraphy. The data includes standard writing and common errors of reverse tip starting, exposed tip starting, hidden tip starting, center tip writing, side tip writing, lifting and pressing writing, back tip ending, out tip ending and hidden tip ending, and the above data are transmitted to the host computer through the wireless transmission module.

[0017] Step 4: The host computer establishes an N×N matrix to write the position area according to the installation position of the pressure sensor array in a 1:1 ratio, stores the sensor pressure data of the corresponding position area to the corresponding position, and records the acquisition time. Assume that the pressure sensor array is an N×N matrix, denoted as P(t), where each element p i,j (t) represents the pressure value of the sensor in the i-th row and j-th column of the sensor array at time t. The upper computer rectangular writing position area is also an N×N matrix, denoted as R, where each element r(i,j,t) represents the pressure value of the sensor in the i-th row and j-th column at time point t, and the upper left corner is the starting point. The upper computer uses the Kalman filter algorithm to smooth the data collected by the pressure sensor array to eliminate the influence of noise.

[0018] Step 5: The host computer extracts features from the data collected by the pressure sensor array to obtain sensor feature data of standard writing and common incorrect writing. The sensor feature data of standard writing and common incorrect writing include the pressure value during standard writing, the standard deviation of the pressure value, the writing path direction, the rate of change of the writing path direction, the smoothness of the writing pressure change, the writing speed, the centerline offset, and the pen tip offset. The pressure sensor reading at the writing position is r(i, j, t). The host computer plots the reading r(i, j, t) of the pressure sensor during standard writing as a pressure curve, finds the peak TFR of the pressure curve, which is the upper limit of the force of the standard writing of the writer, and finds the trough TGR of the curve, which is the lower limit of the force of the standard writing of the writer. The maximum value of the force TFR of the standard writing of all operators is taken as the upper limit of the interval, and the minimum value TGR is taken as the lower limit of the interval, that is, the pressure sensor force value interval is [min{TGR}, max{TFR}], which is used as the basis for judging whether the writing force is appropriate; for each time point t, extract the maximum pressure value Rm(t) of the pressure sensor array, and calculate the standard deviation σ of the pressure value during the writing process R , , is the mean of the maximum pressure value time series; by analyzing the changes in pressure data, the writing path direction is determined, and for each time point t, the maximum position A(i t , j t ), calculate the path direction at each time point t, that is, the direction d from time point t−1 to t t ,d t =arctan((j t -j t-1 ) / (i t -i t-1 ) ; Calculate the rate of change of the path direction dd, calculate d t With d t-1 The difference dd is used to indicate the rate of change of the path direction; t Determine the writing path direction. For each time point t, extract the maximum pressure value Rm(t) of the pressure sensor array and calculate the gradient G(t) of the pressure time series, that is, the pressure change between adjacent time points. G(t)=Rm(t+1)−Rm(t). For t=1,2,…,T−1, calculate the absolute value of the pressure gradient |G(t)| and take the average value Smean to evaluate the smoothness of the pressure change. |G(t)|=abs(G(t)), where abs is the absolute value operation. ; The writing speed v(t) is calculated by analyzing the time series of the pressure sensor data during the writing process, and the writing speed is approximately calculated by the rate of change of the path direction; the trajectory of the maximum pressure point in the pressure sensor array at each time point in the writing process is recorded to form a path, P(t)=(i t ,j t ), where i t and j t are the row and column coordinates of the sensor array, respectively. Assuming that the ideal midline position is a fixed row or column, such as i c or c , then the deviation of the pen tip from the center line can be expressed as Δc(t)=abs(j t −j c ) or Δc(t)=abs(i t −i c ), calculate the mean value mean(Δc) of the offset Δc(t) from each point in the path to the center line, which is used to represent the center line offset, and calculate the actual offset Δside(t) of the pen tip relative to the ideal side tip trajectory (assuming that the trajectory is parallel to a certain center line and has a fixed offset di), Δside(t)=abs((j t −j c )−di), calculate the mean value of the offset mean(Δs), which is used to represent the pen tip offset.

[0019] Step 6: Use sensor feature data to establish a pen-starting operation training and evaluation model. The pen-starting operation training and evaluation model includes reverse-tip pen-starting, exposed-tip pen-starting, and hidden-tip pen-starting training and evaluation. The standard writing of reverse-tip pen-starting is moderate reverse-tip pen-starting force and correct reverse-tip pen-starting direction. The correct reverse-tip pen-starting direction means that the pen tip first goes against the direction of the stroke and then turns to write in the positive direction. Common errors in writing are too much or too little reverse-tip pen-starting force, wrong reverse-tip pen-starting angle, and unnatural turning of the tip. The sensor data of reverse-tip pen-starting is analyzed and features are extracted. The extracted features mainly include the pressure value, writing path direction, and writing path direction change rate when writing reverse-tip pen-starting. According to the method for extracting the pressure value characteristics when writing in a standard manner as described in the fifth step, the pressure value when writing in a standard manner when starting with the tip of the pen is extracted, that is, the force value interval when writing in a standard manner when starting with the tip of the pen is [min{TGR}, max{TFR}], which is used as a basis for judging whether the force of starting with the tip of the pen is moderate. When the writer writes, the pressure sensor value is within this interval, indicating that the force of starting with the tip of the pen is moderate. When it exceeds max{TFR}, it indicates that the force of starting with the tip of the pen is too large. When it is lower than min{TGR}, it indicates that the force of starting with the tip of the pen is too small. According to the method for extracting the direction characteristics of the writing path as described in the fifth step, the direction characteristics of the writing path when starting with the tip of the pen are extracted, and the direction characteristics of the writing path when starting with the tip of the pen are calculated at different times d when starting with the tip of the pen tIf the value is negative first and then positive, it indicates that the writing direction of the reverse pen is correct, otherwise it indicates that the reverse pen starting angle is incorrect; according to the method of extracting the writing path direction change rate feature described in step 5, the writing path direction change rate feature when the reverse pen is started is extracted, and d is calculated. t With d t-1 The difference dd, if dd is less than the set threshold Td, the turning of the pen tip is natural, otherwise it is unnatural. Td is the maximum value obtained when writing in a standard way. Standard writing of starting with a pen tip is as follows: the force of starting with a pen tip is moderate, the writing direction is correct, and the pen tip is stable when starting with a pen tip. The correct writing direction of starting with a pen tip means that the pen tip moves directly in the direction of the stroke. Common writing errors are too much or too little force when starting with a pen tip, the wrong angle of starting with a pen tip, and unstable pen tip when starting with a pen tip. The sensor data when starting with a pen tip is analyzed and features are extracted. The extracted features mainly include the pressure value, path direction, and smoothness of the writing pressure change when writing with a pen tip. According to the method for extracting the pressure value features of standard writing described in the fifth step, the pressure value of starting with a pen tip is extracted. The pressure value during standard writing, that is, the force value interval during standard writing with the tip of the pen exposed is [min{TGR}, max{TFR}], which is used as the basis for judging whether the force of the pen exposed is moderate. When the writer writes, the pressure sensor value is within this interval, indicating that the force of the pen exposed is moderate. When it exceeds max{TFR}, it indicates that the force of the pen exposed is too large. When it is lower than min{TGR}, it indicates that the force of the pen exposed is too small. According to the method for extracting the direction feature of the writing path described in the fifth step, the direction feature of the writing path when the tip of the pen is exposed is extracted, and the different moments d of the pen exposed at different times are calculated. t value, which is always positive, indicating that the writing direction of the pen tip is correct, otherwise it indicates that the writing angle of the pen tip is incorrect; according to the method for extracting the smoothness characteristics of the writing pressure change when the pen tip is started, the smoothness characteristics of the writing pressure change when the pen tip is started are extracted, and G(t) and |G(t)| and Smean are calculated. If |G(t)| is less than the set threshold TGl and Smean is less than the set threshold TSl, the pen tip is stable when the pen tip is started, otherwise it indicates that the pen tip is unstable when the pen tip is started. TGl is the maximum value of |G(t)| when the pen tip is written in a standard manner, and TSl is the maximum value of Smean when the pen tip is written in a standard manner. Standard writing of hiding the tip of the pen means that the speed of hiding the tip of the pen is accurate and the force is uniform when hiding the tip of the pen is started. The uniform force when hiding the tip of the pen means that the tip of the pen touches the paper lightly and the force is applied slowly so that the tip of the pen is completely hidden in the stroke. Common errors are uneven force when hiding the tip of the pen is started and the speed of hiding the tip of the pen is too fast or too slow. The sensor data when hiding the tip of the pen is started is analyzed and features are extracted. The extracted features mainly include the pressure standard deviation and writing speed when hiding the tip of the pen is started. According to the method of extracting the pressure value standard deviation feature when standard writing is performed in the fifth step, the pressure standard deviation of standard writing when hiding the tip of the pen is extracted, and σ is calculated. R , if σ RIf it is less than the set threshold value Tcq, the force is uniform when the pen is hidden, otherwise it indicates that the force is uneven when the pen is hidden. Tcq is the standard writing time of the pen hidden. R The maximum value obtained. According to the method of extracting writing speed characteristics described in step 5, calculate v(t). If v(t) is within the speed interval [vcqmin, vcqmax], it indicates that the speed of starting the pen with the tip of the pen is accurate. If it exceeds vcqmax, it indicates that the speed of starting the pen with the tip of the pen is too fast. If it is less than vcqmin, it indicates that the speed of starting the pen with the tip of the pen is too slow. vcqmin is the minimum speed when the pen is starting with the tip of the pen, and vcqmax is the maximum speed when the pen is starting with the tip of the pen.

[0020] Step 7: Use sensor feature data to establish a pen operation training and evaluation model. The pen operation training and evaluation model includes center-point pen, side-point pen, and lift-and-press pen training and evaluation. The standard writing of center-point pen is that the pen tip is located in the middle of the stroke and the pen force is uniform. Uniform pen force means that the pen shaft is kept vertical or nearly vertical to the paper surface when writing. Common errors in writing are that the pen tip deviates from the center line and the pen force is uneven. The sensor data of center-point pen is analyzed and features are extracted. The extracted features mainly include the center line offset of center-point pen and the smoothness of writing pressure changes. According to the method for extracting the center line offset feature described in the fifth step, the center line offset feature is extracted when the center is written, and the center line offset mean (Δc) is calculated. If mean (Δc) is less than the set threshold Tc, the center tip of the center pen is located in the middle of the stroke and the pen tip does not deviate from the center line. Otherwise, the pen tip deviates from the center line. Tc is the threshold for deviation from the center line in standard writing. According to the method for extracting the smoothness characteristics of writing pressure changes described in the fifth step, the smoothness characteristics of writing pressure changes when writing with the center of the pen are extracted, and G(t) and |G(t)| and Smean are calculated. If |G(t)| is less than the set threshold TGz and Smean is less than the set threshold TSz, it indicates that the writing force is uniform, otherwise it indicates that the writing force is uneven. TGz is the maximum value of |G(t)| when writing with the center of the pen in a standard manner, and TSz is the maximum value of Smean when writing with the center of the pen in a standard manner. Standard writing with a side-tip pen is characterized by proper pen tip offset and natural pen force changes. Proper pen tip offset means that the pen tip is biased to one side and the pen shaft is slightly tilted when writing. Common writing errors are excessive or insufficient pen tip offset and unnatural pen force changes. The sensor data when writing with a side-tip pen is analyzed and features are extracted. The extracted features mainly include the pen tip offset of the side-tip pen and the smoothness of the writing pressure change. According to the method for extracting pen tip offset features described in the fifth step, the pen tip offset mean (Δs) when writing with a side-tip pen is extracted. If the pen tip offset mean (Δs) does not exceed the threshold TSS, it indicates that the pen tip is not offset. The offset is appropriate, otherwise it indicates that the pen tip is over- or under-offset; according to the method for extracting the smoothness characteristics of writing pressure changes described in the fifth step, the smoothness characteristics of writing pressure changes when writing with a side-tip pen are extracted, and G(t) and |G(t)| and Smean are calculated. If |G(t)| is less than the set threshold TGc and Smean is less than the set threshold TSc, the change in writing force when writing with a side-tip pen is natural, otherwise it indicates that the change in writing force when writing with a side-tip pen is unnatural. TGc is the maximum value of |G(t)| obtained when writing with a side-tip pen in a standard manner, and TSc is the maximum value of Smean obtained when writing with a side-tip pen in a standard manner.Standard writing of lifting and pressing requires uniform lifting and pressing force and accurate lifting and pressing rhythm during writing. Accurate lifting and pressing rhythm means changing the lifting and pressing of the pen according to needs. Common writing errors include improper control of lifting and pressing force and uneven lifting and pressing rhythm. The sensor data during lifting and pressing are analyzed and features are extracted. The extracted features mainly include the standard deviation of pressure and writing speed during lifting and pressing writing. According to the method of extracting the standard deviation features of pressure values ​​during standard writing described in the fifth step, the standard deviation of pressure during lifting and pressing writing is extracted, and σ is calculated. R , if σ R If it is less than the set threshold value TTA, the lifting and pressing force of the pen is uniform. Otherwise, it indicates that the lifting and pressing force of the pen is improperly controlled. TTA is the standard writing time σ R The maximum value is obtained. According to the method of extracting writing speed features described in step 5, v(t) is calculated. If v(t) is within the speed interval [vtamin, vtamax], it indicates that the rhythm of the pen is accurate. Otherwise, it indicates that the rhythm of the pen is uneven. vtamin is the minimum speed when the pen is written in a standard manner, and vtamax is the maximum speed when the pen is written in a standard manner.

[0021] Step 8: Use sensor feature data to establish a pen-closing operation training and evaluation model. The pen-closing operation training and evaluation model includes training and evaluation of returning to the tip of the pen, ending with the tip of the pen and hiding the tip of the pen. The standard writing of returning to the tip of the pen is that the writing force of the returning tip of the pen is moderate and the angle of the returning tip of the pen is correct. The correct angle of the returning tip of the pen means that the pen tip turns back and ends the pen smoothly. Common errors in writing are that the force of returning to the tip of the pen is too large or too small and the angle of returning to the tip of the pen is incorrect. The sensor data when returning to the tip of the pen is analyzed and features are extracted. The extracted features mainly include the pressure value during writing and the direction of the writing path. According to the fifth step, the pressure value features of the standard writing are extracted. The method extracts the pressure value when the back-stroke is written in a standard manner, that is, the range of the force value when the back-stroke is written in a standard manner is [min{TGR}, max{TFR}], which is used as a basis for judging whether the back-stroke force is moderate. When the writer writes, the pressure sensor value is within this range, indicating that the back-stroke force is moderate. When it exceeds max{TFR}, it indicates that the back-stroke force is too large. When it is lower than min{TGR}, it indicates that the back-stroke force is too small. According to the method for extracting the direction feature of the writing path described in the fifth step, the direction feature of the writing path when the back-stroke is written is extracted, and the back-stroke force at different times d is calculated. tIf the value is positive first and then negative, it means that the angle of the stroke is correct. Otherwise, it means that the angle of the stroke is incorrect. The standard writing of the pen tip and the pen end is that the force of the pen tip and the pen end is uniform and the angle of the pen tip and the pen end is correct. The correct angle of the pen tip and the pen end means that the pen tip quickly extends outward to form a sharp pen end effect. Common incorrect writing is uneven force of the pen tip and the pen end is incorrect. The sensor data when the pen tip and the pen end are analyzed and features are extracted. The extracted features mainly include the smoothness of the change in writing pressure and the direction of the writing path. According to the method for extracting the smoothness feature of the change in writing pressure described in the fifth step, the smoothness feature of the change in writing pressure when the pen tip and the pen end are extracted, and G(t) and |G(t)| and Smean are calculated. If |G(t)| is less than the set threshold TGch and Smean is less than the set threshold TSch, it indicates that the force of the pen tip and the pen end is uniform. Otherwise, it indicates that the force of the pen tip and the pen end is uneven. TGch is the maximum value of |G(t)| obtained when the pen tip and the pen end are written in a standard way, and TSch is the maximum value of Smean obtained when the pen tip and the pen end are written in a standard way. According to the method for extracting the direction features of the writing path described in step 5, the direction features of the writing path when the tip of the pen is drawn are extracted, and the direction features of the writing path when the tip of the pen is drawn are calculated at different times d t The value is always positive, indicating that the angle of the pen tip is correct, otherwise it indicates that the angle of the pen tip is incorrect. The standard writing of the pen tip is uniform and accurate. The uniform force of the pen tip means that the pen tip is gently retracted and gradually lifted. Common errors are uneven force and inappropriate speed. The sensor data when the pen tip is hidden is analyzed and features are extracted. The extracted features mainly include the smoothness of the change in writing pressure and the writing speed when the pen tip is hidden. According to the method for extracting the smoothness feature of the pressure change during standard writing described in the fifth step, the smoothness feature of the writing pressure change when the pen tip is hidden is extracted. G(t) and |G(t)| and Smean are calculated. If |G(t)| is less than the set threshold TGca and Smean is less than the set threshold TSca, then it means The force of the ending of the stroke is uniform, otherwise it means that the force of the ending of the stroke is uneven. TGca is the maximum value of |G(t)| when the ending of the stroke is written in a standard way, and TSca is the maximum value of Smean when the ending of the stroke is written in a standard way. According to the method of extracting writing speed characteristics described in the fifth step, v(t) is calculated. If v(t) is in the speed interval [vcamin,vcamax], it means that the ending speed of the stroke is accurate. If it exceeds vcamax, it means that the ending speed of the stroke is too fast. If it is less than vcamin, it means that the ending speed of the stroke is too slow, which indicates that the ending speed is inappropriate. vcamin is the minimum speed when the ending of the stroke is written in a standard way, and vcamax is the maximum speed when the ending of the stroke is written in a standard way.

[0022] Step 9: Conduct horizontal writing training and evaluation of basic strokes. According to the reverse pen starting training and evaluation in the pen starting operation training and evaluation model established in step 6, evaluate the horizontal pen starting writing. If the force value range is within the standard writing range [min{TGR}, max{TFR}], it means that the reverse pen starting force is moderate. If it exceeds max{TFR}, it means that the reverse pen starting force is too strong. If it is lower than min{TGR}, it means that the reverse pen starting force is too weak. Calculate the reverse pen starting force at different times d. t The value satisfies the condition that it is negative first and then positive, indicating that the writing direction of the reverse pen is correct, otherwise it indicates that the reverse pen starting angle is incorrect; the horizontal pen writing is evaluated according to the center pen training evaluation in the pen operation training evaluation model established in the seventh step, and the center line offset mean(Δc) is calculated when writing. If mean(Δc) is less than the set threshold value Tc, the center pen tip is located in the middle of the stroke and does not deviate from the center line, otherwise the pen tip deviates from the center line; according to the method for extracting the smoothness feature of the writing pressure change when the center pen is writing as described in the fifth step, the smoothness feature of the writing pressure change when the center pen is writing is extracted, and G(t), |G(t)| and Smean when the center pen is writing are calculated when writing. If |G(t)| is less than the set threshold value TGz and Smean is less than the set threshold value TSz, it indicates that the writing force The degree of uniformity is obtained, otherwise it indicates that the force is uneven when writing. TGz is the maximum value of |G(t)| when writing with the center of the pen in a standard manner, and TSz is the maximum value of Smean when writing with the center of the pen in a standard manner. According to the pen-ending training evaluation model established in the eighth step, the horizontal pen-ending writing is evaluated, and G(t), |G(t)| and Smean are calculated when the pen is written with the tip of the pen. If |G(t)| is less than the set threshold TGch and Smean is less than the set threshold TSch, it indicates that the force of the pen is uniform, otherwise it indicates that the force of the pen is uneven. TGch is the maximum value of |G(t)| when writing with the tip of the pen in a standard manner, and TSch is the maximum value of Smean when writing with the tip of the pen in a standard manner. Calculate the different moments d of the pen-ending. t If the value is always positive, it means the angle of the pen tip is correct, otherwise it means the angle of the pen tip is incorrect. The host computer will give the operator real-time feedback of the result.

[0023] Step 10: Conduct basic stroke writing training and evaluation. According to the pen-starting operation training and evaluation model established in step 6, the writing of the pen-starting stroke is evaluated. It shows that the pen-starting force is moderate. If it exceeds max{TFR}, it means that the pen-starting force is too strong. If it is lower than min{TGR}, it means that the pen-starting force is too weak. Calculate the pen-starting force at different times d tThe value is always positive, indicating that the writing direction of the exposed pen tip is correct and the pen tip moves directly in the direction of the stroke, otherwise it indicates that the angle is wrong when the exposed pen tip is started; calculate G(t), |G(t)| and Smean when the exposed pen tip is started. If |G(t)| is less than the set threshold TGl and Smean is less than the set threshold TSl, the pen tip is stable when the exposed pen tip is started, otherwise it indicates that the pen tip is unstable when the exposed pen tip is started. TGl is the maximum value of |G(t)| when the exposed pen tip is written in a standard way, and TSl is the maximum value of Smean when the exposed pen tip is written in a standard way; evaluate the writing of the slanting pen according to the side-tip pen training evaluation in the pen operation training evaluation model established in the seventh step. When writing, the pen tip offset mean(Δs) does not exceed the threshold TSS, indicating that the pen tip offset is appropriate, otherwise it indicates that the pen tip offset is excessive or insufficient; calculate G(t), |G(t)| and Smean when writing with a side-tip pen. If |G( t)| is less than the set threshold TGc and Smean is less than the set threshold TSc, then the change of the writing force of the side-tip pen is natural, otherwise it indicates that the change of the writing force of the side-tip pen is unnatural. TGc is the maximum value of |G(t)| when the side-tip pen is written in a standard way, and TSc is the maximum value of Smean when the side-tip pen is written in a standard way. According to the pen-ending training evaluation model established in the eighth step, the writing of the left-falling stroke is evaluated, and G(t), |G(t)| and Smean when the pen-ending stroke is written are calculated. If |G(t)| is less than the set threshold TGch and Smean is less than the set threshold TSch, it indicates that the pen-ending force is uniform, otherwise it indicates that the pen-ending force is uneven. TGch is the maximum value of |G(t)| when the pen-ending stroke is written in a standard way, and TSch is the maximum value of Smean when the pen-ending stroke is written in a standard way. Calculate the pen-ending stroke at different times d t If the value is always positive, it means the angle of the pen tip is correct, otherwise it means the angle of the pen tip is incorrect. The host computer will give the operator real-time feedback of the result.

[0024] Step 11: Conduct basic stroke writing training and evaluation. According to the pen-starting operation training and evaluation model established in step 6, evaluate the writing of the pen-starting stroke. Calculate the standard deviation of the pressure when writing, and calculate σ R , if σ RIf it is less than the set threshold value Tcq, it indicates that the force is uniform when the pen is hidden, otherwise it indicates that the force is uneven when the pen is hidden. Calculate v(t). If v(t) is within the speed interval [vcqmin, vcqmax], it indicates that the speed of the pen is accurate. If it exceeds vcqmax, it indicates that the speed of the pen is too fast. If it is less than vcqmin, it indicates that the speed of the pen is too slow. According to the side-tip writing training evaluation in the pen operation training evaluation model established in the seventh step, the writing of the downward stroke is evaluated. When writing, calculate the pen tip offset mean(Δs). If the pen tip offset mean(Δs) does not exceed the threshold value TSS, it indicates that the pen tip offset is appropriate. Otherwise, it indicates that the pen tip offset is excessive or insufficient. Calculate G(t) and |G(t)| and Smean. If |G(t)| is less than the set threshold TGc and Smean is less than the set threshold TSc, it indicates that the force change of the side-stroke writing is natural. Otherwise, it indicates that the force change of the side-stroke writing is unnatural. According to the pen-ending operation training and evaluation model established in the eighth step, the writing of the downward stroke is evaluated. When the force value is within the interval [min{TGR}, max{TFR}], it indicates that the writing force of the back-stroke writing is moderate. If it exceeds max{TFR}, it indicates that the force is too strong when the pen is ending. If it is lower than min{TGR}, it indicates that the force is too weak when the back-stroke writing is ending. Calculate the back-stroke writing force at different times d. t If the value is positive first and then negative, it means the angle of the pen is correct. Otherwise, it means the angle of the pen is wrong. The upper computer will give the operator real-time feedback of the result.

[0025] Step 12: Conduct basic stroke vertical hook writing training and evaluation. According to the reverse pen starting training and evaluation in the pen starting operation training and evaluation model established in step 6, the vertical hook starting writing is evaluated. If the writing force value range is within the standard writing range [min{TGR}, max{TFR}], it indicates that the writing force is moderate. If it exceeds max{TFR}, it indicates that the reverse pen starting force is too large. If it is lower than min{TGR}, it indicates that the reverse pen starting force is insufficient. Calculate the reverse pen starting force at different times d. t If the value is negative first and then positive, it means that the writing direction of the reverse pen is correct. Otherwise, it means that the reverse pen angle is incorrect. The direction change rate of the writing path when the reverse pen is started is extracted, that is, d t With d t-1 The difference dd is calculated. If dd is less than the set threshold value Td, the turning of the pen tip is natural, otherwise it is unnatural. Td is the maximum value obtained during standard writing. According to the lifting and pressing pen operation training evaluation model established in the seventh step, the vertical hook pen writing is evaluated. The pressure standard deviation σ is calculated during writing. R , if σ RIf the value is less than the set threshold value TTA, the force of the pen is uniform, otherwise it indicates that the force of the pen is improperly controlled. Calculate v(t). If v(t) is within the speed interval [vtamin, vtamax], it indicates that the rhythm of the pen is accurate, otherwise it indicates that the rhythm of the pen is uneven. According to the training and evaluation of the pen-closing operation established in the eighth step, the vertical hook writing is evaluated. When the pen is closed, calculate G(t) and |G(t)| and Smean. If |G(t)| is less than the set threshold value TGca and Smean is less than the set threshold value TSca, it indicates that the force of the pen is uniform, otherwise it indicates that the force of the pen is uneven. Calculate v(t). If v(t) is within the speed interval [vcamin, vcamax], it indicates that the speed of the pen is accurate. If it exceeds vcamax, it indicates that the speed is too fast. If it is less than vcamin, it is too slow, indicating that the speed of the pen is inappropriate. The host computer will feedback the results to the operator in real time.

[0026] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A soft brush calligraphy basic stroke training and evaluation device, comprising a pressure sensor array module, a data acquisition module, a wireless transmission module and a host computer; characterized in that: The pressure sensor array module is a capacitive touch sensor array, which is used to collect the writing force and position changes of the writer during the writing process. The data acquisition module uses a multi-channel analog-to-digital converter and a microcontroller for data acquisition, and reads the real-time pressure data of the pressure sensor array module through the microcontroller. The wireless transmission module transmits the real-time pressure data collected by the data acquisition module to the host computer, and the host computer analyzes and processes the real-time pressure data, evaluates the writer's basic stroke writing process and gives feedback. The host computer is provided with a pen-starting operation training and evaluation model, a pen-traveling operation training and evaluation model, wherein the pen-starting operation training and evaluation model includes reverse pen-starting, exposed pen-starting and hidden pen-starting training and evaluation; the pen-traveling operation training and evaluation model includes center pen-traveling, side pen-traveling and lift-and-press pen-traveling training and evaluation; the pen-traveling operation training and evaluation model includes return pen-traveling, exposed pen-traveling and hidden pen-traveling training and evaluation.

2. A soft brush calligraphy basic stroke training and evaluation device according to claim 1, characterized in that: The device adopts a soft brush calligraphy basic stroke training and evaluation method to realize soft brush calligraphy basic stroke writing training and evaluation; the soft brush calligraphy basic stroke training and evaluation method comprises the following steps: step one, analyzing the standard writing and common incorrect writing in the process of starting, running and ending of the soft brush calligraphy basic stroke writing, the starting methods include reverse tip starting, exposed tip starting and hidden tip starting, the standard writing of reverse tip starting is moderate reverse tip starting force, correct reverse tip starting writing direction and natural turning tip, the common incorrect writing is too large or too small reverse tip starting force, wrong reverse tip starting angle and unnatural turning tip; exposed tip starting standard writing is moderate reverse tip starting force, correct reverse tip starting writing direction and natural turning tip; the common incorrect writing is too large or too small reverse tip starting force, wrong reverse tip starting angle and unnatural turning tip; exposed tip starting standard writing is moderate reverse tip starting force, correct reverse tip starting writing direction and natural turning tip; exposed tip starting standard writing is moderate reverse tip starting force, correct reverse tip starting writing direction and natural turning tip; exposed tip starting standard writing is moderate reverse tip starting force, correct reverse tip starting writing direction and natural turning tip; exposed tip starting standard writing is moderate reverse tip starting force, correct reverse tip starting angle and unnatural turning tip; exposed tip starting standard writing is moderate reverse tip starting force, correct reverse tip starting direction and unnatural turning tip; exposed tip starting standard writing is moderate reverse tip starting force, correct reverse tip starting angle and unnatural turning tip; exposed tip starting standard writing is moderate reverse tip starting force, correct reverse tip starting direction and unnatural turning tip; exposed tip starting standard writing is moderate reverse tip starting force, correct reverse tip starting angle and unnatural turning tip; exposed tip starting standard writing is moderate reverse tip starting force, correct reverse tip starting direction and unnatural turning tip; exposed tip starting standard writing is moderate reverse tip starting force, correct reverse tip starting angle and unnatural turning tip; exposed tip starting standard writing is moderate reverse tip starting force, correct reverse tip starting angle and unnatural turning tip; exposed tip starting standard writing is moderate reverse tip starting force, correct reverse tip starting angle and unnatural turning tip; exposed tip starting standard writing is moderate reverse tip starting force, correct reverse tip starting angle and unnatural turning tip; exposed tip starting standard writing is moderate reverse tip starting force, correct reverse tip starting angle and unnatural turning tip; exposed tip starting Writing requires moderate force when the pen tip is exposed, correct writing direction when the pen tip is exposed, and steady pen tip when the pen tip is exposed. Common mistakes include excessive or insufficient force when the pen tip is exposed, incorrect angle when the pen tip is exposed, and unstable pen tip when the pen tip is exposed. Standard writing requires accurate speed and uniform force when the pen tip is exposed. Common mistakes include uneven force when the pen tip is exposed, and too fast or too slow speed when the pen tip is exposed. The writing methods include center-point writing, side-point writing, and lifting and pressing writing. Standard writing requires the pen tip to be located in the middle of the stroke and the force of the writing is uniform. Common mistakes include the pen tip deviating from the center line and uneven force. Standard writing style of writing with side-edge pen is that the pen tip is deflected appropriately and the pen force changes naturally. Common mistakes in writing are excessive or insufficient deflection of the pen tip and unnatural changes in pen force. The standard writing of lifting and pressing is that the lifting and pressing force is even and the lifting and pressing rhythm is accurate during the writing process. Common mistakes are improper control of lifting and pressing force and uneven lifting and pressing rhythm. The methods of finishing the stroke include returning the tip of the brush to finish the stroke, ending the stroke with the tip of the brush and ending the stroke with the tip of the brush hidden. The standard writing of returning the tip of the brush to finish the stroke is that the writing force of the returning tip of the brush is moderate and the angle of the returning tip of the brush to finish the stroke is correct. Common mistakes are that the force of returning the tip of the brush to finish the stroke is too large or too small and the angle of returning the tip of the brush to finish the stroke is incorrect. The standard writing of ending the stroke with the tip of the brush to finish the stroke is that the force of the tip of the brush to finish the stroke is even and the angle of the tip of the brush to finish the stroke is correct. Common mistakes are that the force of the tip of the brush to finish the stroke is uneven and the angle of the tip of the brush to finish the stroke is incorrect. The standard writing method of hiding the tip of the brush is to have even force and accurate speed. Common mistakes are uneven force and inappropriate speed. Step 2: Collect pressure sensor data of standard writing and common incorrect writing of basic strokes of soft brush calligraphy through the pressure sensor array module, embed the pressure sensor array arranged in the form of N´N matrix under the writing surface, measure the pressure applied to the writing surface during writing, use a multi-channel analog-to-digital converter and a microcontroller to convert the analog signal of the pressure sensor into a digital signal, and transmit the pressure sensor array data and collection time collected by the data collection module to the host computer through the wireless transmission module; Step 3: The host computer establishes an N×N matrix writing position area according to the installation position of the pressure sensor array in a 1:1 ratio, which corresponds to the pressure sensor array arranged in the N×N matrix on the writing surface one by one, and stores the data collected by the pressure sensor array into the matrix writing position area corresponding to each sensor, and records the collection time at the same time; The host computer uses the Kalman filter algorithm to smooth the data collected by the pressure sensor array, eliminate the influence of noise, and extract features from the noise-eliminated data to obtain sensor feature data of standard writing and common incorrect writing. Then, the sensor feature data is used to establish a pen-starting operation training and evaluation model, a pen-moving operation training and evaluation model, and a pen-ending operation training and evaluation model. Step 4: Evaluate the entire writing process of the writer based on the pen-starting operation training evaluation model, the pen-travel operation training evaluation model and the pen-ending operation training evaluation model to determine whether the writer's writing is standard. If the writing is standard, give a standard conclusion; if the writing is not standard, give a specific name, corresponding reasons and suggestions.

3. A soft brush calligraphy basic stroke training and evaluation device according to claim 2, characterized in that: In step 3, the pressure sensor array is an N×N matrix, denoted as P(t), where each element p i,j (t) represents the pressure value of the pressure sensor in the i-th row and j-th column of the pressure sensor array at time t. Assume that the writing position area of ​​the host computer matrix is ​​also an N×N matrix, denoted as R, where each element r(i,j,t) represents the pressure value of the sensor in the i-th row and j-th column at time point t, and the upper left corner of the matrix is ​​specified as the starting origin.

4. A soft brush calligraphy basic stroke training and evaluation device according to claim 3, characterized in that: In the step three, the host computer extracts features from the data collected by the pressure sensor array to obtain sensor feature data for standard writing and common incorrect writing, wherein the sensor feature data for standard writing and common incorrect writing include the pressure value during standard writing, the standard deviation of the pressure value, the writing path direction, the rate of change of the writing path direction, the smoothness of the writing pressure change, the writing speed, the centerline offset, and the pen tip offset; the host computer plots the indication r(i, j, t) of the pressure sensor during the writer's standard writing into a pressure curve, finds the peak TFR of the pressure curve, which is the upper limit of the force of the writer's standard writing, finds the trough TGR of the curve, which is the lower limit of the force of the writer's standard writing, takes the maximum value of the force TFR of the standard writing of all operators as the upper limit of the interval, and takes the minimum value TGR as the lower limit of the interval, that is, the pressure sensor force value interval is [min{TGR}, max{TFR}], which is used as a basis for judging whether the writing force is appropriate; for each time point t, extracts the maximum pressure value Rm(t) of the pressure sensor array, and calculates the standard deviation σ of the pressure value during the writing process. R , , is the mean of the maximum pressure value time series; by analyzing the changes in pressure data, the writing path direction is determined, and for each time point t, the maximum position A(i t , j t ), calculate the path direction at each time point t, that is, the direction d from time point t−1 to t t , d t =arctan((j t -j t-1 ) / (i t -i t-1 ) ; Calculate the rate of change of the path direction dd, that is, calculate d t With d t-1 The difference dd is used to indicate the rate of change of the writing path direction; t Determine the direction of the writing path. For each time point t, extract the maximum pressure value Rm(t) of the pressure sensor array and calculate the gradient G(t) of the pressure time series, that is, the pressure change between adjacent time points. G(t)=Rm(t+1)−Rm(t). For t=1,2,…,T−1, calculate the absolute value of the pressure gradient |G(t)| and take the average value Smean to evaluate the smoothness of the writing pressure change. |G(t)|=abs(G(t)), where abs is the absolute value operation. ;The writing speed v(t) during the writing process is calculated by analyzing the time series of the pressure sensor data; Record the trajectory of the maximum pressure point in the pressure sensor array at each time point during the writing process to form a path, P(t)=(i t ,j t ), where i t and j t are the row and column coordinates of the pressure sensor array, respectively. Assuming that the ideal midline position is a fixed row or column, such as i c or c , then the deviation of the pen tip from the center line can be expressed as Δc(t)=abs(j t −j c ) or Δc(t)=abs(i t −i c ), calculate the mean value mean(Δc) of the offset Δc(t) from each point in the path to the center line, which is used to represent the center line offset; calculate the actual offset Δside(t) of the pen tip relative to the ideal side tip trajectory. Assuming that the ideal side tip trajectory is parallel to a certain center line and has a fixed offset di, then Δside(t)=abs((j t −j c )−di), calculate the mean value mean(Δs) of the offset, which is used to represent the pen tip offset.

5. A soft brush calligraphy basic stroke training and evaluation device according to claim 4, characterized in that: In the step 3, the sensor characteristic data is used to establish a pen-starting operation training and evaluation model; the standard writing of the reverse-tip pen-starting is moderate reverse-tip pen-starting force, correct reverse-tip pen-starting direction and natural turning of the pen tip, wherein the correct reverse-tip pen-starting direction means that the pen tip first gently hooks back against the direction of the stroke, and then turns to the positive direction of the pen, and common incorrect writing is that the reverse-tip pen-starting force is too large or too small, the reverse-tip pen-starting angle is incorrect and the turning of the pen tip is unnatural; the pressure sensor data when the reverse-tip pen-starting is analyzed and features are extracted, and the extracted features include the pressure value when the reverse-tip pen-starting is written, the writing path direction and the writing path direction change rate; the standard writing force value interval [min{TGR}, max{TFR}] when the reverse-tip pen-starting is extracted as a basis for judging whether the reverse-tip pen-starting force is moderate. When the writer writes, the pressure sensor value is within this interval, indicating that the reverse-tip pen-starting force is moderate, exceeding max{TFR}, indicating that the reverse-tip pen-starting force is too large, and below min{TGR}, indicating that the reverse-tip pen-starting force is too small; calculate the reverse-tip pen-starting time d t If the value is negative first and then positive, it means that the writing direction of the reverse pen is correct. Otherwise, it means that the reverse pen angle is incorrect. The direction change rate of the writing path when the reverse pen is started is extracted, that is, d t With d t-1 The difference dd is calculated. If dd is less than the set threshold value Td, the turning of the pen tip is natural, otherwise the turning of the pen tip is unnatural. Td is the maximum value obtained when writing in a standard way. The standard writing of the pen tip starting with a pen tip is as follows: the pen tip starting with a moderate force, the writing direction of the pen tip starting with a pen tip is correct, and the pen tip is stable when writing in a standard way. The correct writing direction of the pen tip starting with a pen tip is that the pen tip moves directly in the direction of the stroke. Common incorrect writing is that the pen tip starting with a force that is too large or too small, the pen tip starting with a wrong angle, and the pen tip is unstable when writing in a standard way. The pressure sensor data when writing in a standard way is analyzed and features are extracted to provide a method for The features include the pressure value when writing with the tip exposed, the direction of the writing path and the smoothness of the writing pressure change, and the force value interval [min{TGR}, max{TFR}] of the standard writing when the tip is exposed is extracted as the basis for judging whether the force of the pen is moderate. When the writer writes, the pressure sensor value is within this interval, indicating that the force of the pen is moderate. When it exceeds max{TFR}, it indicates that the force of the pen is too large. When it is lower than min{TGR}, it indicates that the force of the pen is too small. Calculate the different moments d when the tip is exposed. t If the value is always positive, it means that the writing direction of the pen tip is correct and the pen tip moves directly in the direction of the stroke. Otherwise, it means that the writing angle is wrong when the pen tip is started. Calculate G(t), |G(t)| and Smean when the pen is exposed. If |G(t)| is less than the set threshold TGl and Smean is less than the set threshold TSl, the pen tip is stable when the pen is exposed. Otherwise, it indicates that the pen tip is unstable when the pen is exposed. TGl is the maximum value of |G(t)| when the pen is exposed, and TSl is the maximum value of Smean when the pen is exposed. The standard writing of the hidden pen is accurate and the force is uniform when the pen is hidden. The uniform force when the pen is hidden means that the pen tip touches the paper lightly and the force is applied slowly so that the pen tip is completely hidden in the stroke. Common errors are uneven force and too fast or too slow speed when the pen is hidden. The pressure sensor data when the pen is hidden is analyzed and features are extracted. The extracted features include the pressure standard deviation σ when the pen is hidden. R and writing speed v(t), calculate the standard deviation of pressure σ when starting to write with the tip of the pen hidden R , if σ R If it is less than the set threshold value Tcq, the force is uniform when the pen is hidden, otherwise it indicates that the force is uneven when the pen is hidden. Tcq is the standard writing time of the pen hidden. R The maximum value obtained; calculate the writing speed v(t) when the pen is started with the tip of the pen hidden. If v(t) is in the speed range [vcqmin,vcqmax], it means that the speed of starting with the tip of the pen is accurate. If it exceeds vcqmax, it means that the speed of starting with the tip of the pen is too fast. If it is less than vcqmin, it means that the speed of starting with the tip of the pen is too slow. vcqmin is the minimum speed when the pen is started with the tip of the pen hidden, and vcqmax is the maximum speed when the pen is started with the tip of the pen hidden.

6. A soft brush calligraphy basic stroke training and evaluation device according to claim 4, characterized in that: In the step three, the sensor feature data is used to establish a pen operation training and evaluation model; standard writing with a center pen is that the pen tip is located in the middle of the stroke and the writing force is uniform. The uniform writing force means that the pen shaft is kept vertical or nearly vertical to the paper surface when writing. Common writing errors are that the pen tip deviates from the center line and the writing force is uneven. The pressure sensor data when the pen is written with a center pen is analyzed and features are extracted. The extracted features include the center line offset when the pen is written with a center pen and the smoothness of the writing pressure change; the center line offset mean (Δc) is calculated. If mean (Δc) is less than the set threshold value Tc, the pen tip of the center pen is located in the middle of the stroke and does not deviate from the center line. Otherwise, the pen tip deviates from the center line. Tc is the threshold value for deviation from the center line in standard writing; Calculate G(t), |G(t)| and Smean when writing with the center of the pen. If |G(t)| is less than the set threshold TGz and Smean is less than the set threshold TSz, it indicates that the pen stroke force is uniform. Otherwise, it indicates that the pen stroke force is uneven. TGz is the maximum value of |G(t)| when writing with the center of the pen in a standard manner, and TSz is the maximum value of Smean when writing with the center of the pen in a standard manner. Standard writing with a side-tip pen is characterized by appropriate pen tip offset and natural pen force changes. Appropriate pen tip offset means that the pen tip is biased to one side and the pen shaft is slightly tilted when writing. Common writing errors are excessive or insufficient pen tip offset and unnatural pen force changes. The pressure sensor data when writing with a side-tip pen is analyzed and features are extracted. The extracted features include the pen tip offset mean (Δs) and the smoothness of the writing pressure change. If the pen tip offset mean (Δs) does not exceed the threshold TSS, it indicates that the pen tip is appropriately offset, otherwise it indicates that the pen tip is excessive or insufficient. G(t), |G(t)| and Smean when writing with a side-tip pen are calculated. If |G(t)| is less than the set threshold TSS, Gc and Smean is less than the set threshold TSc, then the change of the writing force of the side-tip pen is natural, otherwise it indicates that the change of the writing force of the side-tip pen is unnatural. TGc is the maximum value obtained by |G(t)| when writing with the side-tip pen in a standardized way, and TSc is the maximum value obtained by Smean when writing with the side-tip pen in a standardized way. The standardized writing of lifting and pressing means that the lifting and pressing force is uniform and the lifting and pressing rhythm is accurate during the writing process. Accurate lifting and pressing rhythm means that the lifting and pressing of the pen are changed according to the needs. Common writing errors are improper control of the lifting and pressing force and uneven lifting and pressing rhythm. The pressure sensor data during lifting and pressing is analyzed and features are extracted. The extracted features include the pressure standard deviation σ during lifting and pressing writing R and writing speed v(t), calculate the standard deviation of pressure when writing with the pen lifted and pressed σ R , if σ R If it is less than the set threshold value TTA, the lifting and pressing force of the pen is uniform, otherwise it indicates that the lifting and pressing force of the pen is improperly controlled. TTA is the standard writing time of lifting and pressing the pen. R The maximum value obtained; calculate the writing speed v(t) when lifting and pressing the pen. If v(t) is within the speed range [vtamin,vtamax], it indicates that the rhythm of lifting and pressing the pen is accurate, otherwise it indicates that the rhythm of lifting and pressing the pen is uneven. vtamin is the minimum speed when lifting and pressing the pen in a standard way, and vtamax is the maximum speed when lifting and pressing the pen in a standard way.

7. A soft brush calligraphy basic stroke training and evaluation device according to claim 4, characterized in that: In the step three, the sensor characteristic data is used to establish a training and evaluation model for the finishing operation; the standard writing of the back-tip finishing stroke is that the writing force of the back-tip finishing stroke is moderate and the back-tip finishing angle is correct, the correct back-tip finishing angle means that the pen tip rotates smoothly to finish the stroke, and common incorrect writing is that the back-tip finishing force is too large or too small and the back-tip finishing angle is incorrect. The pressure sensor data when the back-tip finishing stroke is analyzed and features are extracted. The extracted features include the pressure value and the writing path direction during standard writing. The force value interval [min{TGR}, max{TFR}] of the standard writing when the back-tip finishing stroke is extracted as a basis for judging whether the back-tip finishing force is moderate. When the writer writes, the pressure sensor value is within this interval, indicating that the back-tip finishing force is moderate. When it exceeds max{TFR}, it indicates that the back-tip finishing force is too large. When it is lower than min{TGR}, it indicates that the back-tip finishing force is too small. Calculate the back-tip finishing stroke at different times d t The value satisfies the condition that the positive value is first followed by the negative value, indicating that the angle of the back-stroke is correct, otherwise it indicates that the angle of the back-stroke is incorrect; the standard writing of the tip-out pen is that the tip-out pen force is uniform and the tip-out pen angle is correct. The correct tip-out pen angle means that the tip of the pen quickly extends outward to form a sharp pen ending effect. Common errors in writing are uneven tip-out pen force and incorrect tip-out pen angle. The pressure sensor data during the tip-out pen is analyzed and features are extracted. The extracted features include the smoothness of the change in writing pressure and the direction of the writing path. G(t), |G(t)| and Smean during the tip-out pen writing are calculated. If |G(t)| is less than the set threshold TGch and Smean is less than the set threshold TSch, it indicates that the tip-out pen force is uniform, otherwise it indicates that the tip-out pen force is uneven. TGch is the maximum value obtained by |G(t)| when the tip-out pen is written in a standard way, and TSch is the maximum value obtained by Smean when the tip-out pen is written in a standard way; the tip-out pen at different times d is calculated t If the value is always positive, it means the angles of the pen tip and the pen end are correct; otherwise, it means the angles of the pen tip and the pen end are incorrect. The standard writing of hiding the tip of the pen and ending the stroke is that the force of hiding the tip of the pen is uniform and the speed of hiding the tip of the pen is accurate. The uniform force of hiding the tip of the pen means that the pen tip is gently retracted and gradually lifted up. Common incorrect writing is uneven force of hiding the tip of the pen and inappropriate speed of hiding the tip of the pen. The pressure sensor data when hiding the tip of the pen is closed is analyzed and features are extracted. The extracted features include the smoothness of the writing pressure change and the writing speed when hiding the tip of the pen is closed. G(t), |G(t)| and Smean when writing when hiding the tip of the pen are closed are calculated. If |G(t)| is less than the set threshold TGca and Smean is less than the set threshold TSca, it indicates that the force of hiding the tip of the pen is uniform. Otherwise, it indicates that the tip of the pen is closed. The force of ending the stroke is uneven, TGca is the maximum value of |G(t)| when the stroke is written in a standard manner, and TSca is the maximum value of Smean when the stroke is written in a standard manner; calculate the writing speed v(t) when the stroke is written in a standard manner. If v(t) is in the speed range [vcamin,vcamax], it means that the speed of ending the stroke is accurate. If it exceeds vcamax, it means that the speed of ending the stroke is too fast. If it is less than vcamin, it means that the speed of ending the stroke is too slow, which means that the speed of ending the stroke is inappropriate. vcamin is the minimum speed when the stroke is written in a standard manner, and vcamax is the maximum speed when the stroke is written in a standard manner.