CN106200642A - The two-wheeled balance car of a kind of realizing route automatic Memory and reproduction independently goes on patrol method - Google Patents

Abstract

The present invention relates to an autonomous patrol method for a two-wheeled balance car that realizes automatic path memory and reappearance. The balance car is equipped with a controller and a mileage measurement device. The method includes: after the controller is initialized, select a patrol mode, If it is in the route memory mode, the self-balancing car starts to drive from the starting point, and the mileage measuring device samples the mileage of the left wheel and the right wheel respectively, and the controller generates route record data according to the mileage sampling data, and writes it into the external memory until the end of the drive. If it is in the path reappearance mode, the controller reads the path record data from the external memory to make the balance car drive according to the path. Compared with the prior art, the present invention discards the middle segment data of linear motion or circular motion and Data, to overcome the problem of huge data volume caused by the local repeatability of path information, only record valid data, discard redundant path information, easy to operate, good stability, and high real-time performance.

Description

A two-wheeled self-balancing vehicle autonomous patrol method that realizes automatic path memory and reappearance

technical field

The invention relates to a path memory and reappearance method for a self-balancing vehicle, in particular to an autonomous patrol method for a two-wheeled self-balancing vehicle that realizes automatic path memory and reappearance.

Background technique

In recent years, due to its flexible movement, intelligent control, simple operation, energy saving, green environmental protection and other characteristics, two-wheeled balance vehicles have been more and more widely used in modern transportation tools, such as daily transportation tools, police patrols, advertising Publicity, auxiliary shooting, etc. However, in addition to its manned function, the two-wheeled balance car, as a member of the robot family, can replace patrol robots in many occasions to complete many tasks after being equipped with some sensors on the basis of its basic functions such as automatic walking and attitude adjustment. Tasks, such as power station inspection, community security, daily patrol, environmental monitoring, military reconnaissance, etc.

For the self-balancing car with autonomous patrol function, one of the important functions is to record and save the route information of the self-balancing car, so that in different application scenarios, it only needs to control the self-balancing car to patrol once, and then the self-balancing car can follow the route. The data memorized during the process reproduces the path and completes the patrol autonomously. For a two-wheeled balance car equipped with an odometer, the memory path information is to record the mileage, speed and other information of the left and right wheels through a preset time period (such as every 10ms). When the patrol path distance is long or it needs to be stored When there are many paths, the amount of data is huge, which will occupy a large amount of storage space. In fact, many data recorded by the self-balancing vehicle during the driving process are redundant data, which are not necessary for reproducing the path. Therefore, it is necessary to provide a A path memory and reappearance method for a two-wheeled self-balancing vehicle, the method can greatly save the amount of data stored when the self-balancing vehicle memorizes the path.

Contents of the invention

The object of the present invention is to provide a two-wheel balance car autonomous patrol method with small data storage capacity and high reliability to realize automatic path memory and reappearance in order to overcome the above-mentioned defects in the prior art.

The purpose of the present invention can be achieved through the following technical solutions:

An autonomous patrol method for a two-wheeled self-balancing vehicle that realizes automatic path memory and reappearance, the self-balancing vehicle is provided with a controller and a mileage measuring device, and the method includes:

After the controller is initialized, select the patrol mode. If it is the path memory mode, the self-balancing car starts to drive from the starting point. The mileage measurement device samples the mileage data of the left wheel and the right wheel respectively. The controller generates path record data according to the mileage sampling data, and Write to the external memory until the end of driving. If it is in the route reproduction mode, the controller reads the route record data from the external memory to make the self-balancing vehicle drive according to the route.

The path record data includes multiple sets of calculation data stored in sequence. Each set of calculation data is calculated from the left wheel mileage S _Li and the right wheel mileage S _Ri at a certain sampling time. Each set of calculation data includes: the left wheel mileage difference △S at the sampling time _Li , left wheel speed V _Li and left and right wheel speed difference △V _LRi , wherein, i represents the sequence number of the sampling moment, left wheel mileage difference △S _Li = S _Li - S _Li-1 , S _Li is the left wheel mileage at the sampling moment, S _Li-1 is the mileage of the left wheel at the sampling time of the last set of saved calculation data, the speed of the left wheel V _Li =(S _Li -S _Li-1 )/T, T is the sampling interval, the speed difference between the left and right wheels ΔV _LRi =V _Li -V _Ri =(S _Li -S _Li-1 )/T-(S _Ri -S _Ri-1 )/T, V _Ri is the speed of the right wheel, and its calculation principle is the same as that of the left wheel speed V _Li .

In path memory mode, the controller calculates each set of calculation data in real time, and judges whether the set of calculation data is saved or discarded. Among them, the calculation data of the starting point or the end point are saved, and the judgment rules for the calculation data of non-starting point or end point are: Between the sampling time of the previous set of calculation data and the sampling time of this set of calculation data, if the motion of the balance car is linear motion (including uniform linear motion and non-uniform linear motion) or circular motion (including uniform circular motion and change non-uniform circular motion) or stop driving, discard this group of calculation data, otherwise save this group of calculation data.

In the path memory mode, the controller calculates each set of calculation data in real time, and judges whether the set of calculation data is saved or discarded, wherein the calculation data of the starting point is saved, and the process of judging the calculation data of non-starting points includes the following steps:

S11, calculate the left and right wheel speed difference change value △△V _LRi , △△V _LRi = △V _LRi - △V _LRi-1 , if △△V _LRi = 0, go to step S12, otherwise go to step S13;

S12, judging whether the set of calculation data corresponds to the end point of the path, if so, saving the set of calculation data, otherwise discarding the set of calculation data;

S13, judging is true, if not, save the set of calculation data, and update the V _L and △V _LR values in the temporary storage unit to the current V _Li and ΔV _LRi , if If it is established, return to step S12, where V _L and △V _LR are the left wheel speed and the left and right wheel speed difference in the last set of saved calculation data, which are stored in the temporary storage unit. During the judgment process, when △V _LRi ＝ When 0, agree When △V _LR =0, the convention

In the path reproduction mode, the controller reads the calculation data from the external memory, and obtains the actual right wheel speed value of the balance car according to the calculation data and the actual left wheel speed value of the balance car. Between the two sets of calculation data, the left and right wheels of the balance car The velocity difference remains constant until the next set of calculated data is reproduced.

In the path memory mode, the process of path record data being written into the external memory includes: the controller saves each set of calculation data in the preset write buffer area in sequence, and the data in the write buffer area is packaged and sent to the serial port of the controller. Write to the external memory file.

In the path memory mode, multiple write buffer areas are set, and the path record data is written into the write buffer area in a circular manner, which specifically includes the following steps:

S21, the calculation data in the path record data is stored in the first write buffer in sequence, when the first write buffer is full, the data is packaged and sent to the serial port, and the data in the first write buffer is cleared ;

S22, the subsequent groups of calculation data continue to be written into the next write buffer area in order. After the write buffer area is full, the data is packaged and sent to the serial port, and the data in the buffer area is cleared. If the write buffer area is the last If the cache area is written, return to step S21, otherwise return to step S22 until the last set of calculation data is written.

In the path reproduction mode, the controller reads the calculation data in the external memory in order through the serial port, and stores them in the read buffer in sequence. At the same time, the balance car performs path reproduction according to the calculation data in the read buffer to complete the patrol. process.

In the path reproduction mode, multiple read buffers are set, the number is the same as that of the write buffer, and the path record data is written into the read buffer in a cyclic manner, which specifically includes the following steps:

S31, the controller establishes a connection with the external storage, and selects a corresponding file in the external storage;

S32. The controller reads part of the calculation data in the corresponding file in order through the serial port. The amount of data is determined according to the size of a single read buffer area, and is packed and stored in the first read buffer area. Calculate the data for path reproduction. After the current buffer area is full and the corresponding path reproduction is completed, clear the data in the buffer area;

S33, the subsequent groups of calculation data continue to be packaged and written in the next read buffer in sequence. After the read buffer is full and the corresponding path reproduction is completed, clear the data in the read buffer. If the read buffer is For the last read buffer, return to step S32, otherwise return to step S33 until the last set of calculation data is reproduced.

Compared with the prior art, the present invention has the following advantages:

(1) In the path memory mode, by sampling the mileage of the left and right wheels, the path record data that can realize path reproduction can be generated and stored in the external memory. In the path reproduction mode, by reading the data in the external memory , can guide the balance car to drive according to the route, the external storage can record a large amount of data, has high reliability, and can record multiple standard route information, when the route reappears, select the corresponding data file from the external storage to realize automatic patrol according to the selected route.

(2) The path record data includes multiple sets of calculation data stored in sequence. Each set of calculation data is calculated from the mileage S _Li of the left wheel and the mileage S _Ri of the right wheel at a certain sampling time, including the mileage difference of the left wheel, the speed of the left wheel, and the speed difference between the left and right wheels , through these three data, the current motion state of the self-balancing car and the mileage traveled by the self-balancing car between the two sets of calculation data can be uniquely obtained. When the path is reproduced, the amount of calculation is small, which is conducive to improving the smoothness of the patrol process.

(3) In the path memory mode, from the sampling time of the last set of calculation data to the sampling time of this set of calculation data, if the motion of the self-balancing car is linear motion or circular motion or pauses driving, the current set of calculation data will be discarded. Otherwise, the calculation data of this group is saved, that is, the data of the middle section of linear motion or circular motion and the data during pause are discarded, which overcomes the problem of huge data volume caused by the local repeatability of path information, and only records valid data, discarding redundancy Path information, easy to operate, good stability, high real-time performance.

(4) In the path reproduction mode, between two sets of calculation data, only the ratio of the left and right wheel speed difference to the left wheel speed of the balance car remains unchanged until the next set of calculation data is reproduced, so that the balance car can follow the standard For path walking, there is no absolute limit to the speed of the left and right wheels.

(5) In the patrol mode, multiple write buffer areas are set, and the path record data is written into the write buffer area in a circular manner; Write to the read buffer in a circular manner. The opening of the cache area is conducive to improving the smoothness of path memory and path reproduction.

(6) The hardware is simple to realize, and only needs to be equipped with an odometer on the left wheel and the right wheel respectively, and the cost is low.

Description of drawings

Fig. 1 is the block flow diagram of the present embodiment method;

Fig. 2 is a flow chart for judging whether to discard the data at the current moment in the path memory mode of the method of the present embodiment;

FIG. 3 is a flow chart of storing data into a preset write buffer in the path memory mode of the method of this embodiment.

detailed description

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is carried out on the premise of the technical solution of the present invention, and detailed implementation and specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

Example

The core of the two-wheel balancing autonomous patrol car control system in this embodiment adopts the ARM chip STM32 of the Cortex M3 core, and an odometer is respectively mounted on the left wheel and the right wheel of the self-balancing car to record the mileage of the left wheel and the right wheel during the traveling process of the self-balancing car respectively Cumulative value. After the balance car is turned on, the accumulated mileage values S _Li and S _Ri of the left and right wheels are respectively collected according to a certain sampling time interval T (such as T=10ms), where i represents the i-th sampling time sequence number.

The present invention includes two parts, one is the method for the two-wheel balanced autonomous patrol car to automatically memorize the patrol path according to the set format, and write the path information into the external storage according to a certain format and order, and the other is the two-wheel balance The car reproduces the path, that is, the method for the self-balancing car to patrol according to the path stored in the external storage.

The data record format of the sampling time that needs to be recorded is:

Left wheel mileage difference △S _Li : left wheel speed value V _Li : left and right wheel speed difference △V _LRi

Among them, the left wheel mileage difference △S _Li is the difference between the current left wheel odometer mileage value and the left wheel odometer mileage value at the last recording point, and the current left wheel speed value is calculated from the left wheel mileage value and the sampling time interval, that is, V _Li =(S _Li -S _Li-1 )/T, the left and right wheel speed difference at the current moment △V _i refers to the difference between the left wheel speed value and the right wheel speed value, that is, ΔV _LRi =V _Li -V _Ri =(S _Li - S _Li-1 )/T-(S _Ri -S _Ri-1 )/T. The mileage difference of the left wheel, the speed value of the left wheel, and the speed difference between the left and right wheels are all 64-bit integer values, that is, long type values.

Referring to FIG. 1 , it is a flowchart of a method for automatically memorizing and reappearing a path for a two-wheeled autonomous patrol vehicle of the present invention. After the two-wheeled self-balancing scooter is initialized, the mode of patrolling is determined according to the value of the mode parameter mode. If mode=0, the path memory mode patrol is enabled, and if mode=1, the path recurrence mode patrol is enabled.

The patrol process of the two-wheel balance car in the path memory mode includes the following steps:

First, the self-balancing car starts patrolling from the starting point, the initial values of accumulated mileage of the left and right wheels are S _L0 and S _R0 respectively, and the initial value of the left wheel mileage difference is set to ΔS _L0 =0. After the balance car starts to move, the accumulated mileage values of the left and right wheels are respectively collected according to a certain sampling time interval T. Assuming that the collection time sequence number is i (i=1,2,3,...), the accumulated mileage values of the left and right wheels are respectively Denoted as S _Li and S _Ri , the left wheel mileage difference △S _Li , the left wheel speed value V _Li and the left and right wheel speed difference △V _LRi can be obtained according to the aforementioned calculation method.

If the balance car is in a straight line motion (including uniform linear motion and non-uniform linear motion) or turning motion (including uniform turning motion and non-uniform turning motion with constant curvature rate) within a certain period of time, the turning motion is circular motion, then You can only record the data values at the start time and end time of the period, and the data in the middle period can be discarded. In addition, the data of the period when the self-balancing car stops temporarily at a certain point during the patrol process can also be discarded.

The data values of the starting point and the ending point of the self-balancing car patrol path must always be recorded. When the self-balancing car reaches the starting point, the system will give a flag signal f _start , and record the starting point time data according to the format. When the end point is reached, the system will give a flag signal f _end and record the time data of the end point according to the format. Under normal circumstances, the data values △S _Li , V _Li and △V _LRi of the start point and the end point are all zero.

Open up two data storage units in the internal memory to temporarily store V _L and △V _LR respectively. The initial value of these two data is the value at the starting point. When the data at a certain moment is judged as a record, V _L and △V The value of _LR is updated to the value of the current moment, otherwise it remains unchanged. When judging whether the data at a certain time point is recorded or not, first temporarily store the data V _Li and △V _LRi at that time point, and then judge based on the temporarily stored values V _L and △V _LR . When moving in a straight line, △V _LRi = 0, △△V _LRi = |△V _LRi -△V _LR |=0; if the current moment is a uniform turning movement relative to the last recorded moment, △△V _LRi = |△V _LRi -△V _LR |＝0; and for non-uniform turning motion, the △V _LR and △△V _LRi at the current time point relative to the previous recording time are not zero, and it needs to be judged in combination with the turning curvature. For non-uniform turning motion with fixed value, the data value in the middle period can also be discarded.

Assuming that the radius of curvature in a certain section of the turning path is ρ, the formula for the radius of curvature is:

$\mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; V</span>}}{\mathrm{<span\; class="notranslate">\; w</span>}}<span\; class="notranslate">\; =</span>\frac{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; R</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; R</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; R</span>}}$

Among them, V is the linear velocity of the center of mass of the self-balancing vehicle, w is the angular velocity of the center of mass of the self-balancing vehicle, V _L is the linear velocity of the left wheel of the self-balancing vehicle, VR is the linear velocity of the right wheel of the self-balancing vehicle, ΔV _LR = V _L -V _R , and _R is the left wheel of the self-balancing vehicle The distance between the two axles of the right wheel and the right wheel.

If the current moment is a non-uniform turning motion with constant curvature relative to the last recorded moment, ρ _i = ρ, that is:

${\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>\frac{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; R</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; =</span>\frac{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; R</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; R</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; R</span>}}$

After simplification, we get Therefore, it can be judged whether it is a non-uniform turning motion with constant curvature according to whether the ratio of the left wheel speed to the left and right wheel speed difference changes.

If the self-balancing car temporarily stops at a certain point during the patrol process, the data during the pause period can also be discarded, at this time △V _LRi =0, △△V _LRi =0.

According to the above derivation, refer to Figure 2, the process of judging whether the current data is discarded is as follows:

First judge whether the balance car has reached the starting point, if the current time has reached the starting point, record the data value at that time, and store the V _L and △V _LR values at that time in the temporary storage unit of the memory; if not the starting point, then Temporarily store the V _Li and △V _LRi values of this point, and combine the V _L and △V _LR values in the temporary storage unit to _judge . If it is the termination point, the data value at the current moment is judged as a record, if it is not the termination point, the data at the current moment will not be recorded; when △△V _LRi ! = 0, then judge Whether it is true, if not, the data value at the current moment is determined as a record, and the value of V _L and △V _LR in the temporary storage unit is updated with the current moment value; if If it is established, turn to the node to judge whether the point is the end point. It should be noted that the judgment Under this condition, there are two special cases, one is when △V _LRi ＝0 and △V _LR ≠0, corresponding to the turning point when the balance car changes from linear motion to turning motion; the other is when △V _LRi ≠0 and △ V _LR =0, corresponding to the turning point when the balance car changes from turning motion to linear motion. The data at these two turning points should be recorded, but at this time This calculation formula is meaningless, so here is a convention: when △V _LRi =0, the convention When △V _LR =0, the convention

According to this judgment criterion, straight line motion and turning motion only record the data values at the start time and end time of the movement, and the data values at other time points need to be recorded. Write to the preset write buffer area of STM32. The size and number of preset write buffers are determined by parameters such as sampling interval, storage data format, serial port transmission rate, and external storage write rate. Take two preset write buffer areas as an example, please refer to the attached picture 3, two preset write buffer areas A and B of equal size are opened in STM32, and the buffer area flag signal flag=0 is set during initialization, which needs to be written When writing data, first write buffer area A, when buffer area A is full, set the flag signal to 1, pack the data in buffer area A to the serial port, and clear the data in buffer area A at the same time, ARM receives data through the serial port And write to the external SD card file. Subsequent data will be written into the buffer area B one after another. Similarly, when the buffer area B is full, the flag signal is set to 0, the data in the buffer area B is packaged and sent to the serial port, and the data in the buffer area B is cleared at the same time. Receive data through the serial port and continue to write to the external SD card file. All the data to be recorded are cyclically written into the buffer areas A and B according to this method and finally saved in the external SD file. The capacity of the external SD card is determined by parameters such as the storage data format, the total distance of the memory path, and the maximum number of memory paths.

When the balance car reaches the end point, the memory of this patrol path is ended, and the data file stored in the SD card of this continuous path is named Road_N, where N represents the Nth patrol path recorded (N=1,2,3 ,…), all path files are stored in the external memory, and the path automatic memory function is completed. All patrol paths in the external memory can be used by the two-wheeled autonomous patrol vehicle when the path is reproduced.

The patrol process of the two-wheel balance vehicle in the path reappearance mode includes the following steps.

First, the self-balancing car selects a certain path Road_N in the external memory, and prepares to patrol along this path. There are multiple read buffers preset in STM32, the number and size of which are the same as those of the aforementioned write buffers. Still taking the two read buffer areas as an example, the preset read buffer area is divided into buffer area C and buffer area D, both of which have the same size as buffer area A.

ARM reversely reads part of the data in the file Road_N in the order of storage, and the amount of data is determined by the size of buffer C (or buffer D). Contrary to the data storage process in the path memory process, the data is first packaged and sent to the STM32 through the serial port, and stored in the read buffer area C. After the storage is completed, ARM continues to reversely read the remaining files in the file Road_N in the order of storage. Send the data to the STM32 through the serial port, and store it in the read buffer area D. At the same time, the STM32 reads the data packets in the buffer area C, and controls the direction and distance of the balance car according to the mileage comparison method. When this path is reproduced, clear the data in the buffer area C, and store the subsequent data in the buffer area C according to this method. At the same time, STM32 reads the data packets in the buffer area D, and controls the balance car according to the mileage comparison method direction and route. According to this method, the data packets in the buffer area C and the buffer area D are alternately read in a cycle, and the balance car reproduces the cycle path according to these data.

When reading the data in the read buffer area, it is judged according to the characteristics of the data whether it is a linear motion or a turning motion in certain periods of time, and the STM32 controls the direction and distance of the balance car according to the mileage comparison method.

If the △V _LR of the previous recording point in two adjacent recording points is 0, then the movement of this segment is linear motion, and STM32 controls the balance car to walk in a straight line according to the data of this segment according to the mileage comparison method, that is, record data according to the latter recording point The mileage difference △S Li of the left wheel in △S _Li determines the distance that the car travels in a straight line.

If △V _LR ≠0 of the previous record point in the two adjacent record points, then the movement in this segment is a turning movement, and the specific method of STM32 controlling the balance car to travel according to the mileage comparison method is as follows.

Assuming that the radius of curvature of this section of the turning movement in the predetermined standard path (that is, a path automatically memorized) is ρ, the formula for the radius of curvature is:

$\mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; V</span>}}{\mathrm{<span\; class="notranslate">\; w</span>}}<span\; class="notranslate">\; =</span>\frac{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; R</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; R</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; R</span>}}$

Among them, V is the linear velocity of the center of mass of the self-balancing vehicle, w is the angular velocity of the center of mass of the self-balancing vehicle, V _L is the linear velocity of the left wheel of the self-balancing vehicle, VR is the linear velocity of the right wheel of the self-balancing vehicle, ΔV _LR = V _L -V _R , and _R is the left wheel of the self-balancing vehicle The distance between the two axles of the right wheel and the right wheel.

In order to ensure that the balance car follows the standard path in the reappearance path, it must be guaranteed that it also turns at a constant speed with a fixed curvature ρ, and its curvature is ρ', that is, it needs to satisfy:

ρ'=ρ

which is:

$\frac{<span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; R</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}}{<span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; R</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; R</span>}}<span\; class="notranslate">\; =</span>\frac{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; R</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; R</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; R</span>}}$

Among them, V _L ' is the linear velocity of the left wheel when the self-balancing car reproduces the path, VR ' is the linear velocity of the right wheel when the _self -balancing car reproduces the path, V _L '=V _R '+ΔV _LR '.

After simplification, we get:

$\frac{{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; R</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}}{{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; R</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}}$

According to the left wheel speed value V _L and the left and right wheel speed difference △V _LR recorded at the previous record point, the left wheel speed V _L and the right wheel speed V _R can be obtained. When reproducing the path, the left wheel linear speed V _L ' of the self-balancing vehicle can be set value, the linear velocity V _R ' of the right wheel of the balance vehicle can be calculated according to the above formula. Combined with the mileage difference △S _L of the left wheel of the last data point, the balance vehicle can be controlled to move △S _L according to these three parameters, and the balance vehicle can complete this turning movement according to the standard path in the reappearance path.

When all the data in the file Road_N has been read into the buffer area one after another, the self-balancing car has completed the journey in sequence according to all the data recorded in the buffer area. of reappearance.

Claims (10)

1. A two-wheeled self-balancing car autonomous patrol method that realizes path automatic memory and reappearance, described self-balancing car has controller and mileage measuring device, it is characterized in that, described method comprises: After the controller is initialized, select the patrol mode. If it is the path memory mode, the self-balancing car starts to drive from the starting point. The mileage measurement device samples the mileage data of the left wheel and the right wheel respectively. The controller generates path record data according to the mileage sampling data, and Write to the external memory until the end of driving. If it is in the route reproduction mode, the controller reads the route record data from the external memory to make the self-balancing vehicle drive according to the route. 2. A method for autonomous patrolling of two-wheeled balance vehicles that realizes automatic path memory and reappearance according to claim 1, wherein the path record data includes multiple sets of calculation data stored in sequence, and each set of calculation data is composed of a certain set of calculation data. The mileage S _Li of the left wheel and the mileage S _Ri of the right wheel at the sampling moment are calculated. Each set of calculation data includes: the mileage difference △S _Li of the left wheel at the sampling moment, the speed V _Li of the left wheel and the speed difference △V _LRi of the left and right wheels, where i represents The serial number of the sampling time, left wheel mileage difference △S _Li = S _Li —S _Li-1 , S _Li is the left wheel mileage at this sampling time, S _Li-1 is the left wheel mileage at the sampling time where the last set of saved calculation data is located , left wheel speed V _Li ＝(S _Li -S _Li-1 )/T, T is the sampling interval, left and right wheel speed difference ΔV _LRi ＝V _Li -V _Ri , V _Ri is the right wheel speed, its calculation principle is the same as the left wheel speed V _{Li is} the same. 3. A two-wheeled self-balancing vehicle autonomous patrol method that realizes automatic path memory and reproduction according to claim 1 or 2, characterized in that, in the path memory mode, the controller calculates each set of calculation data in real time, and judges the The calculation data of the group is saved or discarded. Among them, the calculation data of the start point or the end point is saved, and the judgment rule for the calculation data other than the start point or the end point is: from the sampling time of the last group of calculation data to the sampling time of the calculation data of this group In between, if the motion of the balance car is linear motion or circular motion or pausing, discard this group of calculation data, otherwise save this group of calculation data. 4. A method for autonomous patrolling of two-wheeled self-balancing vehicles that realizes automatic memory and reappearance of paths according to claim 2, wherein, in path memory mode, the controller calculates each group of calculation data in real time, and judges the calculation data of the group. The data is saved or discarded. Among them, the calculation data of the starting point is saved, and the judgment process of the calculation data of the non-starting point includes the following steps: S11, calculate the left and right wheel speed difference change value △△V _LRi , △△V _LRi = △V _LRi - △V _LRi-1 , if △△V _LRi = 0, go to step S12, otherwise go to step S13; S12, judging whether the set of calculation data corresponds to the end point of the path, if so, saving the set of calculation data, otherwise discarding the set of calculation data; S13, judging is true, if not, save the set of calculation data, and update the V _L and △V _LR values in the temporary storage unit to the current V _Li and ΔV _LRi , if If it is established, return to step S12, where V _L and △V _LR are the left wheel speed and the left and right wheel speed difference in the last set of saved calculation data, which are stored in the temporary storage unit. During the judgment process, when △V _LRi ＝ When 0, agree When △V _LR =0, the convention 5. A two-wheeled self-balancing vehicle autonomous patrol method that realizes automatic path memory and reproduction according to claim 4, characterized in that, in the path reproduction mode, the controller reads calculation data from an external memory, And according to the calculation data and the actual left wheel speed value of the balance car, the actual right wheel speed value of the balance car is obtained. Between the two sets of calculation data, the ratio of the speed difference between the left and right wheels of the balance car to the left wheel speed remains unchanged until the next step is reproduced. Group calculation data. 6. The autonomous patrol method of a two-wheeled self-balancing vehicle that realizes automatic path memory and reproduction according to claim 1, characterized in that, in path memory mode, the process of path record data being written into the external memory comprises: a controller Save each group of calculation data in the preset write buffer area in order, and the data in the write buffer area is packaged and sent to the serial port of the controller, and written into the external memory file through the serial port. 7. A method for autonomous patrolling of two-wheeled balance vehicles that realizes automatic path memory and reappearance according to claim 6, wherein multiple write buffer areas are provided, and the path record data is written into the write buffer area in a cyclic manner, Specifically include the following steps: S21, the calculation data in the path record data is stored in the first write buffer in sequence, when the first write buffer is full, the data is packaged and sent to the serial port, and the data in the first write buffer is cleared ; S22, the subsequent groups of calculation data continue to be written into the next write buffer area in order. After the write buffer area is full, the data is packaged and sent to the serial port, and the data in the buffer area is cleared. If the write buffer area is the last If the cache area is written, return to step S21, otherwise return to step S22 until the last set of calculation data is written. 8. A two-wheeled self-balancing vehicle autonomous patrol method for automatically memorizing and reproducing the path according to claim 7, characterized in that, in the path reappearance mode, the controller sequentially reads the calculation data in the external memory through the serial port The data is stored in the read buffer in sequence, and at the same time, the balance vehicle performs path reproduction according to the calculated data in the read buffer to complete the patrol process. 9. A two-wheeled self-balancing vehicle autonomous patrol method for automatically memorizing and reproducing the path according to claim 8, characterized in that, in the path reappearance mode, multiple read cache areas are set, and the number is the same as that of the write cache area , the path record data is written to the read buffer in a cyclic manner, which specifically includes the following steps: S31, the controller establishes a connection with the external storage, and selects a corresponding file in the external storage; S32. The controller reads part of the calculation data in the corresponding file in order through the serial port, and packs and stores them in the first read buffer area. At the same time, the balance car reproduces the path according to the calculation data in the read buffer area. After the corresponding path is full and the corresponding path is reproduced, the data in the buffer area is cleared; S33, the subsequent groups of calculation data continue to be packaged and written in the next read buffer in sequence. After the read buffer is full and the corresponding path reproduction is completed, clear the data in the read buffer. If the read buffer is For the last read buffer, return to step S32, otherwise return to step S33 until the last set of calculation data is reproduced. 10. An autonomous patrol method for a two-wheeled self-balancing vehicle that realizes automatic path memory and reappearance according to claim 1, wherein the mileage measuring device includes odometers respectively arranged on the left wheel and the right wheel.