Anti-creeping early warning protection method based on vehicle-mounted charging

Abstract

The invention discloses an anti-creeping early warning protection method based on vehicle-mounted charging, relates to the technical field of electric vehicles, and solves the problems that an existing fixed threshold monitoring mode is extremely easy to generate false alarm; in order to solve the technical problem that accidental data cannot be further distinguished due to the quality problem of equipment, improper installation, poor use environment and the like, two sets of preset threshold value groups are arranged in a main controller, and the state of the battery pack is judged by monitoring the dynamic change of the voltage of the battery pack, so that the reliability of the battery pack is improved. Calling out a corresponding preset threshold group; the method comprises the following steps of: drawing parameters such as real-time voltage and real-time temperature of each element into a curve changing along with time through a main controller, taking a plurality of points in each period by taking T as a period so as to solve the variance of the voltage in each period, comparing the variance with preset variances in a corresponding preset threshold group one by one, and performing corresponding marking according to a comparison result.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicles, and in particular to an anti-leakage early warning protection method based on vehicle-mounted charging. Background Art

[0002] The anti-leakage warning of on-board charging refers to a protection measure set up to prevent leakage when the electric vehicle is charging. As far as I know, the basic principle of the leakage protector on new energy vehicles is similar to that of household leakage protectors. When the currents of the live wire and the neutral wire of the car power supply are not equal, the balance between them is destroyed. At this time, the central control system of the car will cut off the corresponding high-voltage circuit, and the low-voltage circuit will not be cut off;

[0003] However, the current fixed threshold monitoring method is prone to false alarms, and there is no further way to identify accidental data caused by quality problems of the equipment itself, improper installation, poor operating environment, etc. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides an anti-leakage warning protection method based on on-board charging, which solves the problem that the current fixed threshold monitoring method is very prone to false alarms and there is no further method to distinguish accidental data caused by quality problems of the equipment itself, improper installation, poor operating environment and other problems.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: a method for preventing leakage warning protection based on vehicle charging, comprising the following steps:

[0006] S1. The information collection device collects the operating parameters of each component and transmits them to the main controller. The main controller calculates the variance of the voltage value in each cycle and simultaneously identifies the operating stage of the battery pack in the corresponding cycle.

[0007] S11, taking time T as a cycle, and each cycle is recorded as T1, T2, T3, ..., Tn, identifying the operation stage of the battery pack in the corresponding cycle;

[0008] S12, determining the variance of the voltage value within each cycle;

[0009] S2, the main controller sorts out the variance of each component and compares it with the preset threshold group of the corresponding stage, determines the comparison result and records it, and each comparison result has three possibilities, which are respectively recorded as leakage state 2, abnormal state 1 and normal state 0;

[0010] S21. If the battery pack is in the discharge stage during the monitoring cycle, then during this cycle, when the variance of the measured element is greater than the upper endpoint value of the preset threshold group Z1, it is determined that the element is in the leakage state 2, and an alarm message is sent to the battery pack to cut off the electrical connection with the terminal device; if the variance is greater than the lower endpoint value of the preset threshold group Z1 and less than the upper endpoint value of the preset threshold group Z1, it is determined that the element is in the abnormal state 1 during this cycle, and monitoring continues; if the variance is less than the lower endpoint value of the preset threshold group Z1, it is determined that the element is in the normal state 0 during this cycle, and monitoring continues;

[0011] S22. If the battery pack is in the charging stage during the monitoring cycle, then during this cycle, when the variance of the measured element is greater than the upper endpoint value of the preset threshold group Z2, it is determined that the element is in the leakage state 2, and an alarm message is sent to the battery pack to cut off the electrical connection with the terminal device; if the variance is greater than the lower endpoint value of the preset threshold group Z2 and less than the upper endpoint value of the preset threshold group Z2, it is determined that the element is in the abnormal state 1 during this cycle, and monitoring continues; if the variance is less than the lower endpoint value of the preset threshold group Z2, it is determined that the element is in the normal state 0 during this cycle, and monitoring continues;

[0012] S3. The main controller marks the first cycle of the component in which abnormal state 1 occurs, and makes a comprehensive judgment based on the state of the component in the next cycle, marking the component as an abnormal component. The judgment steps are as follows:

[0013] S31, if the next cycle is leakage state 2, the main controller directly sends an alarm message to the battery pack to cut off the electrical connection with the terminal device;

[0014] S32, if the next cycle is abnormal state 1, the main controller determines that the component has leakage and sends an alarm message to the battery pack, so that it cuts off the electrical connection with the terminal device;

[0015] S33, if the next cycle is normal state 0, the main controller determines that the component may have leakage, draws the temperature curve in the cycle and evaluates it according to its temperature change;

[0016] S4. The main controller establishes a temperature change curve based on the real-time temperature data transmitted by the abnormal component, and observes whether the temperature change in this cycle exceeds the relevant preset threshold value;

[0017] S41, when the battery pack is in the discharge stage, the main controller calls out the corresponding preset threshold group X1, and when the real-time temperature of the component exceeds the upper limit endpoint value of the preset threshold group X1, the main controller determines that it is in a thermal runaway state and sends an alarm message to the battery pack;

[0018] When the real-time temperature of the component is greater than the lower endpoint value of the preset threshold group X1 and less than the upper endpoint value of the preset threshold group X1, the component is marked as abnormal in this cycle, and the main controller draws the temperature slope change curve, determines the function expression of the temperature slope change curve, denoted as f1, and finds its range and domain, and compares it with the temperature slope change curve of the component in the normal state. The function expression of the temperature slope change curve in the normal state is denoted as f2; the values ​​of f1 and f2 in the same cycle are respectively stored in two arrays of the same length pi={p1, p2, p3, ..., pb} and qi={q1, q2, q3, ..., qb}, and the difference between the elements at the corresponding positions in the two arrays is calculated to obtain a difference array, denoted as ki={k1, k2, k3..., kb}; i is an ordinal number, and i=1, 2, 3, ..., b; b is the total number of data in each array; the average value K of the difference array is calculated,

[0019] K=1 / b[k1+k2+.......+kb]

[0020] If the overlap rate of K is higher than the preset value, it is determined that the component is in a normal state at this time; if the overlap rate of K is lower than the preset value, it is determined that the component is in an abnormal state at this time;

[0021] When the real-time temperature of the element is lower than the lower limit endpoint value of the preset threshold group X1, the main controller determines that it is in a normal state;

[0022] S42, when the battery pack is in the charging stage, the main controller calls out the corresponding preset threshold group X2, and when the real-time temperature of the component exceeds the upper limit endpoint value of the preset threshold group X2, the main controller determines that it is in a thermal runaway state and sends an alarm message to the battery pack;

[0023] When the real-time temperature of the component is greater than the lower endpoint value of the preset threshold group X2 and less than the upper endpoint value of the preset threshold group X2, the component is marked as abnormal in this cycle, and the main controller draws the temperature slope change curve, determines the function expression of the temperature slope change curve, denoted as f1, and finds its range and domain, and compares it with the temperature slope change curve of the component in the normal state. The function expression of the temperature slope change curve in the normal state is denoted as f2; the values ​​of f1 and f2 in the same cycle are respectively stored in two arrays of the same length pi={p1, p2, p3, ..., pb} and qi={q1, q2, q3, ..., qb}, and the difference between the elements at corresponding positions in the two arrays is calculated to obtain a difference array, denoted as ki={k1, k2, k3..., kb}; i is an ordinal number, and i=1, 2, 3, ..., b; b is the total number of data in each array; the average value K of the difference array is calculated,

[0024] K=1 / b[k1+k2+.......+kb]

[0025] If the overlap rate of K is higher than the preset value, it is determined that the component is in a normal state at this time; if the overlap rate of K is lower than the preset value, it is determined that the component is in an abnormal state at this time;

[0026] When the real-time temperature of the element is lower than the lower limit endpoint value of the preset threshold group X1, the main controller determines that it is in a normal state;

[0027] S5. The main controller will make a joint judgment based on the results of temperature curve observation and the voltage mean judgment results; when the component is in a thermal runaway state or an abnormal state, the main controller sends an alarm message to the battery pack to cut off the electrical connection with the terminal device; when the component is in a normal state, the main controller cancels the judgment of the abnormal state of the voltage mean in the previous cycle and continues monitoring.

[0028] Beneficial Effects

[0029] The present invention provides a leakage prevention early warning protection method based on vehicle charging. Compared with the prior art, it has the following beneficial effects:

[0030] The present invention sets two sets of preset threshold groups in the main controller, monitors the dynamic change of the battery pack voltage, determines its state, and then calls out the corresponding preset threshold group; the main controller plots the real-time voltage and real-time temperature of each component into a curve that changes with time, takes T as a cycle, takes a number of points in each cycle, calculates the variance of the voltage in each cycle, and compares them one by one with the preset variance in the corresponding preset threshold group, and performs corresponding marking according to the comparison result;

[0031] For the components marked in the previous cycle, further monitoring is carried out in the next cycle, and the judgment results of the two cycles are combined to determine their status. If further judgment is impossible, the real-time temperature slope change curve is compared with the temperature slope change curve under normal conditions, and an auxiliary judgment is made based on the comparison results. This method greatly improves the accuracy of early warning and avoids a large number of false alarms caused by accidental data. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The figure is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Embodiment 1

[0035] See also Figure 1 The present application provides a method for preventing leakage warning based on vehicle charging, comprising the following steps:

[0036] S1. The information collection device collects the operating parameters of each component and transmits them to the main controller, wherein the operating parameters include the real-time voltage and real-time temperature of each component. The main controller calculates the variance of the voltage value in each cycle and simultaneously identifies the operating stage of the battery pack in the corresponding cycle. The specific method of confirmation is as follows:

[0037] S11. Take time T as a cycle, and each cycle is recorded as T1, T2, T3, ..., Tn, and identify the operation stage of the battery pack in the corresponding cycle, where the operation stage includes a discharge stage and a charge stage:

[0038] S12. The specific method for determining the variance of the voltage value in each cycle is:

[0039] Fc=1 / n[(x1-m)^2+(x2-m)^2+.....+(xn-m)^2]

[0040] Where Fc is the variance of the data set in this cycle, n is the total number of voltage values ​​measured in each cycle, m is the average value of all voltage values ​​in each cycle, xi is a single independent voltage value among the voltage values ​​measured in each cycle, i = 1, 2, 3, ..., n;

[0041] S2. The main controller compares the variance of each component with the preset threshold group of the corresponding stage, determines the comparison result and records it. There are three possible comparison results each time, which are recorded as leakage state 2, abnormal state 1 and normal state 0. The comparison steps are as follows:

[0042] S21. If the battery pack is in the discharge stage during the monitoring cycle, then during this cycle, when the variance of the measured element is greater than the upper endpoint value of the preset threshold group Z1, it is determined that the element is in the leakage state 2, and an alarm message is sent to the battery pack to cut off the electrical connection with the terminal device; if the variance is greater than the lower endpoint value of the preset threshold group Z1 and less than the upper endpoint value of the preset threshold group Z1, it is determined that the element is in the abnormal state 1 during this cycle, and monitoring continues; if the variance is less than the lower endpoint value of the preset threshold group Z1, it is determined that the element is in the normal state 0 during this cycle, and monitoring continues;

[0043] S22. If the battery pack is in the charging stage during the monitoring cycle, then during this cycle, when the variance of the measured element is greater than the upper endpoint value of the preset threshold group Z2, it is determined that the element is in the leakage state 2, and an alarm message is sent to the battery pack to cut off the electrical connection with the terminal device; if the variance is greater than the lower endpoint value of the preset threshold group Z2 and less than the upper endpoint value of the preset threshold group Z2, it is determined that the element is in the abnormal state 1 during this cycle, and monitoring continues; if the variance is less than the lower endpoint value of the preset threshold group Z2, it is determined that the element is in the normal state 0 during this cycle, and monitoring continues;

[0044] The upper and lower endpoint values ​​of the preset threshold group Z1 and the preset threshold group Z2 are preset values, and their specific values ​​are determined by the operator based on experience;

[0045] S3. The main controller marks the first cycle of the component in which abnormal state 1 occurs, and makes a comprehensive judgment based on the state of the component in the next cycle, marking the component as an abnormal component. The judgment steps are as follows:

[0046] S31, if the next cycle is leakage state 2, the main controller directly sends an alarm message to the battery pack to cut off the electrical connection with the terminal device;

[0047] S32, if the next cycle is abnormal state 1, the main controller determines that the component has leakage and sends an alarm message to the battery pack, so that it cuts off the electrical connection with the terminal device;

[0048] S33. If the next cycle is in the normal state 0, the main controller determines that the component may have leakage, draws the temperature curve in the cycle and evaluates it according to its temperature change, and marks the component as an abnormal component; if the second cycle state is normal, it is impossible to determine whether the previous cycle is a misjudgment, and further judgment is required based on the temperature change in the corresponding cycle. For example: the possible value combinations of the corresponding component in the first cycle in which 1 appears and the next cycle are: 0, 0 or 1, 2 or 1, 1 or 1, 0. When the value group is 0, 0, when the value group is 1, 2 or 1, 1, the main controller needs to send an alarm message to the battery pack; when the value group is 1, 0, the next step of analysis is carried out; when the value combination is 0, 0, the component is safe and the two cycles are skipped automatically.

[0049] Embodiment 2

[0050] In the specific implementation process, this embodiment is different from the first embodiment in that:

[0051] S4. The main controller establishes a temperature change curve according to the real-time temperature data transmitted by the abnormal component, and observes whether the temperature change in this cycle exceeds the relevant preset threshold value, and judges the state of the abnormal component according to the observation result. The specific value of the relevant preset threshold value is determined by the operator based on experience; when the two adjacent cycles before and after the voltage mean value judgment result are respectively displayed as abnormal state 1 and normal state 0, the main controller will be triggered to draw the temperature change curve in this cycle for subsequent judgment;

[0052] S41, when the battery pack is in the discharge stage, the main controller calls out the corresponding preset threshold group X1, and when the real-time temperature of the component exceeds the upper limit endpoint value of the preset threshold group X1, the main controller determines that it is in a thermal runaway state and sends an alarm message to the battery pack;

[0053] When the real-time temperature of the component is greater than the lower endpoint value of the preset threshold group X1 and less than the upper endpoint value of the preset threshold group X1, the component is marked as abnormal in this cycle, and the main controller draws the temperature slope change curve, determines the function expression of the temperature slope change curve, denoted as f1, and finds its range and domain, and compares it with the temperature slope change curve of the component in the normal state. The function expression of the temperature slope change curve in the normal state is denoted as f2; the values ​​of f1 and f2 in the same cycle are respectively stored in two arrays of the same length pi={p1, p2, p3, ..., pb} and qi={q1, q2, q3, ..., qb}, and the difference between the elements at the corresponding positions in the two arrays is calculated to obtain a difference array, denoted as ki={k1, k2, k3..., kb}; i is an ordinal number, and i=1, 2, 3, ..., b; b is the total number of data in each array; the average value K of the difference array is calculated,

[0054] K=1 / b[k1+k2+.......+kb]

[0055] K is the overlap of the two functions in the interval; if the overlap between the two functions is higher than the preset value, the component is considered to be in a normal state at this time; if the overlap between the two functions is lower than the preset value, the component is considered to be in an abnormal state at this time; the function of the temperature slope change curve takes time as the independent variable, so each cycle can be regarded as a section of it, that is, the same cycle is the same interval;

[0056] When the real-time temperature of the element is lower than the lower limit endpoint value of the preset threshold group X1, the main controller determines that it is in a normal state;

[0057] S42, when the battery pack is in the charging stage, the main controller calls out the corresponding preset threshold group X2, and when the real-time temperature of the component exceeds the upper limit endpoint value of the preset threshold group X2, the main controller determines that it is in a thermal runaway state and sends an alarm message to the battery pack;

[0058] When the real-time temperature of the component is greater than the lower endpoint value of the preset threshold group X2 and less than the upper endpoint value of the preset threshold group X2, the component is marked as abnormal in this cycle, and the main controller draws the temperature slope change curve, determines the function expression of the temperature slope change curve, denoted as f1, and finds its range and domain, and compares it with the temperature slope change curve of the component in the normal state. The function expression of the temperature slope change curve in the normal state is denoted as f2; the values ​​of f1 and f2 in the same cycle are respectively stored in two arrays of the same length pi={p1, p2, p3, ..., pb} and qi={q1, q2, q3, ..., qb}, and the difference between the elements at corresponding positions in the two arrays is calculated to obtain a difference array, denoted as ki={k1, k2, k3..., kb}; i is an ordinal number, and i=1, 2, 3, ..., b; b is the total number of data in each array; the average value K of the difference array is calculated,

[0059] K=1 / b[k1+k2+.......+kb]

[0060] K is the overlap of the two functions in the interval; if the overlap between the two functions is higher than the preset value, the component is considered to be in a normal state at this time; if the overlap between the two functions is lower than the preset value, the component is considered to be in an abnormal state at this time; the function of the temperature slope change curve takes time as the independent variable, so each cycle can be regarded as a section of it, that is, the same cycle is the same interval;

[0061] When the real-time temperature of the element is lower than the lower limit endpoint value of the preset threshold group X2, the main controller determines that it is in a normal state.

[0062] S5. The main controller will make a joint judgment based on the results of temperature curve observation and the voltage mean judgment results; when the component is in a thermal runaway state or an abnormal state, the main controller sends an alarm message to the battery pack to cut off the electrical connection with the terminal device; when the component is in a normal state, the main controller cancels the judgment of the abnormal state of the voltage mean in the previous cycle and continues monitoring.

[0063] Embodiment 3

[0064] The specific implementation process of this embodiment includes the entire implementation process of the above two groups of embodiments.

[0065] Some of the data in the above formulas are dimensionless and numerically calculated. Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0066] The above embodiments are only used to illustrate the technical method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. The anti-leakage early warning protection method based on vehicle charging is characterized in that: The following steps are involved: S1. The information collection device collects the operating parameters of each component and transmits them to the main controller. The main controller calculates the variance of the voltage value in each cycle and identifies the operating stage of the battery pack in the corresponding cycle. S2, the main controller sorts out the variance of each component and compares it with the preset threshold group of the corresponding stage, determines and records the comparison results, and records them as leakage state 2, abnormal state 1 and normal state 0 respectively; S3, the main controller marks the first cycle of the component in which abnormal state 1 occurs, and makes a comprehensive judgment based on the state of the component in the next cycle, marking the component as an abnormal component; S4. The main controller establishes a temperature change curve based on the real-time temperature data transmitted by the abnormal component, and observes whether the temperature change in this cycle exceeds the relevant preset threshold value; S5. The main controller will make a joint judgment based on the results of temperature curve observation and the voltage mean judgment results; when the component is in a thermal runaway state or an abnormal state, the main controller sends an alarm message to the battery pack to cut off the electrical connection with the terminal device; when the component is in a normal state, the main controller cancels the judgment of the abnormal state of the voltage mean in the previous cycle and continues monitoring.

2. The anti-leakage early warning protection method based on vehicle charging according to claim 1 is characterized in that: In step S1, the variance acquisition step is: S11, taking time T as a cycle, and each cycle is recorded as T1, T2, T3, ..., Tn, identifying the operation stage of the battery pack in the corresponding cycle; S12. Determine the variance of the voltage value in each cycle.

3. The anti-leakage early warning protection method based on vehicle charging according to claim 1 is characterized in that: In step S2, the comparison steps are: S21. If the battery pack is in the discharge stage during the monitoring cycle, then during this cycle, when the variance of the measured element is greater than the upper endpoint value of the preset threshold group Z1, it is determined that the element is in the leakage state 2, and an alarm message is sent to the battery pack to cut off the electrical connection with the terminal device; if this variance is greater than the lower endpoint value of the preset threshold group Z1 and less than the upper endpoint value of the preset threshold group Z1, it is determined that the element is in the abnormal state 1 during this cycle, and monitoring continues; if this variance is less than the lower endpoint value of the preset threshold group Z1, it is determined that the element is in the normal state 0 during this cycle, and monitoring continues; S22. If the battery pack is in the charging stage during the monitoring cycle, then when the variance of the measured element is greater than the upper endpoint value of the preset threshold group Z2 during this cycle, it is determined that the element is in leakage state 2, and an alarm message is sent to the battery pack to cut off the electrical connection with the terminal device; if this variance is greater than the lower endpoint value of the preset threshold group Z2 and less than the upper endpoint value of the preset threshold group Z2, it is determined that the element is in abnormal state 1 during this cycle, and monitoring continues; if this variance is less than the lower endpoint value of the preset threshold group Z2, it is determined that the element is in normal state 0 during this cycle, and monitoring continues.

4. The anti-leakage early warning protection method based on vehicle charging according to claim 1 is characterized in that: In step S3, the judging steps are as follows: S31, if the next cycle is leakage state 2, the main controller directly sends an alarm message to the battery pack to cut off the electrical connection with the terminal device; S32, if the next cycle is abnormal state 1, the main controller determines that the component has leakage and sends an alarm message to the battery pack, so that it cuts off the electrical connection with the terminal device; S33. If the next cycle is the normal state 0, the main controller determines that the component may have leakage, draws the temperature curve in the cycle and evaluates it according to its temperature change.

5. The anti-leakage early warning protection method based on vehicle charging according to claim 1 is characterized in that: In step S4, the judging step is: S41, when the battery pack is in the discharge stage, the main controller calls out the corresponding preset threshold group X1, and when the real-time temperature of the component exceeds the upper limit endpoint value of the preset threshold group X1, the main controller determines that it is in a thermal runaway state and sends an alarm message to the battery pack; When the real-time temperature of the component is greater than the lower endpoint value of the preset threshold group X1 and less than the upper endpoint value of the preset threshold group X1, the component is marked as abnormal in this cycle, and the main controller draws a temperature slope change curve, determines the function expression of the temperature slope change curve and records it as f1, and finds its range and domain, and compares it with the temperature slope change curve of the component in the normal state. The function expression of the temperature slope change curve in the normal state is recorded as f2; the values ​​of f1 and f2 in the same cycle are respectively stored in two arrays of the same length pi = {p1, p2, p3, ..., pb} and qi = {q1, q2, q3, ..., qb}, and the difference between the elements at corresponding positions in the two arrays is calculated to obtain a difference array; the average value K of the difference array is calculated; If the overlap rate of K is higher than the preset value, it is determined that the component is in a normal state at this time; if the overlap rate of K is lower than the preset value, it is determined that the component is in an abnormal state at this time; When the real-time temperature of the element is lower than the lower limit endpoint value of the preset threshold group X1, the main controller determines that it is in a normal state; S42, when the battery pack is in the charging stage, the main controller calls out the corresponding preset threshold group X2, and when the real-time temperature of the component exceeds the upper limit endpoint value of the preset threshold group X2, the main controller determines that it is in a thermal runaway state and sends an alarm message to the battery pack; When the real-time temperature of the component is greater than the lower endpoint value of the preset threshold group X2 and less than the upper endpoint value of the preset threshold group X2, the component is marked as abnormal in this cycle, and the main controller draws the temperature slope change curve, determines the function expression of the temperature slope change curve, denoted as f1, and finds its range and domain, and compares it with the temperature slope change curve of the component in the normal state. The function expression of the temperature slope change curve in the normal state is denoted as f2; the values ​​of f1 and f2 in the same cycle are respectively stored in two arrays of the same length pi={p1, p2, p3, ..., pb} and qi={q1, q2, q3, ..., qb}, and the difference between the elements at corresponding positions in the two arrays is calculated to obtain a difference array; the average value K of the difference array is calculated, K=1 / b[k1+k2+.......+kb] If the overlap rate of K is higher than the preset value, it is determined that the component is in a normal state at this time; if the overlap rate of K is lower than the preset value, it is determined that the component is in an abnormal state at this time; When the real-time temperature of the element is lower than the lower limit endpoint value of the preset threshold group X1, the main controller determines that it is in a normal state.

Images