KR100807532B1 - Method of detecting remaining amount of battery of mobile robot using power consumption pattern - Google Patents

Abstract

A method for detecting a remaining amount of a battery of a mobile robot using power consumption patterns is provided to efficiently cope with a fading phenomenon of the battery by predicting change of battery capacity on the basis of accumulated data of the power consumption patterns. A method for detecting a remaining amount of a battery of a mobile robot using power consumption patterns includes the steps of: setting predetermined sampling time and sampling frequency(S10); measuring a current and a voltage discharged from the battery and temporarily storing data in a buffer(S24); operating the power consumption patterns by integrating a multiplied value of the discharged current and voltage with respect to time and storing the result in a database(S30); operating total capacity of the battery at the present time by using the power consumption patterns data accumulated through the third step(S40); and measuring the remaining amount of the battery by comparing the power consumption during the total sampling time with the total battery capacity at the present time and detecting expected operation time of the robot by analyzing a shape of the power consumption pattern(S50).

Description

Battery Level Detection Method of Mobile Robot Using Power Consumption Pattern {METHOD OF DETECTING REMAINING AMOUNT OF BATTERY OF MOBILE ROBOT USING POWER CONSUMPTION PATTERN}

1 is a view showing the configuration of a mobile robot applied to the method of detecting the remaining battery of the mobile robot according to the present invention;

2 is a flowchart of a method of detecting a battery remaining amount of a mobile robot according to the present invention.

Figure 3 is a graph illustrating the current and voltage measurement step of the method of detecting the remaining battery level of the mobile robot according to the present invention

Figure 4 is a graph illustrating the remaining amount detection step of the remaining battery detection method of the mobile robot according to the present invention

5 is a graph illustrating a battery capacity calculation step of the method for detecting the remaining battery level of a mobile robot according to the present invention.

The present invention relates to a method of detecting a battery remaining amount of a mobile robot through a power consumption pattern, and more specifically, to accurately predict the remaining battery level of a mobile robot by storing and utilizing a pattern of power consumption during a certain period according to the motion of the mobile robot. The present invention relates to a battery level detection method of a mobile robot.

In recent years, the spread of rechargeable secondary batteries such as nickel hydrogen storage batteries, lithium ion batteries, and lithium polymer batteries has been remarkably spread, and these secondary batteries have been used in all industrial fields including mobile phones.

The mobile robot moves within a certain place and performs a predetermined task. The battery of the mobile robot also uses a secondary battery.

The secondary battery battery mounted on the mobile robot is discharged while the mobile robot performs the work. If the battery does not accurately measure the remaining amount of the battery, the secondary battery battery will be stopped during the work and cause great loss to the work line. Conversely, frequent charging of a battery that is not discharged to a certain level is not only economically inefficient, but also adversely affects the life of the battery. In addition, since the charging time is greatly different depending on how the charging time is set, it will be considered that the charging time determination by measuring the remaining battery amount is an essential element in efficient robot operation.

Conventionally, as a residual amount detection method of a secondary battery battery, a voltage measurement method and a residual amount measurement method by a battery management system (BMS) have been largely applied.

The voltage measurement method is a method of estimating the remaining battery capacity by tracking the decrease of the voltage according to the use of the battery, since there is a threshold point at which the voltage is kept constant and rapidly decreases at a specific time, that is, the discharge curve of the battery by the voltage measurement. Since the decrease in voltage with respect to time is not constant, there is a problem in that the remaining battery prediction under the threshold voltage is inaccurate.

The remaining amount measurement method by BMS estimates the remaining battery capacity by calculating the accumulated discharge value by using the operating current and time used by the device powered from the rechargeable battery while the total charge capacity value of the rechargeable battery is stored. That's the way it is. The remaining amount measurement method by BMS is relatively accurate compared to the remaining amount prediction by voltage, but the error rate increases in a system in which power consumption over time is not constant.

 Since the mobile robot system is a system in which power consumption changes rapidly with time according to the motion of the mobile robot, there are many problems in applying the remaining amount measurement method by the BMS.

In addition, in the BMS system, the value of the rechargeable battery that is initially stored is fixed over time, so that the battery cell is deteriorated due to repeated charging and discharging of the battery, which is suitable for cycle deterioration in which the usable capacity decreases. There is also a problem that can not respond. As a result, in some cases, even when the battery level is indicated to be sufficient, the battery level may actually be low and the mobile robot may suddenly stop.

The present invention is to solve the above problems, an object of the present invention is to easily predict the remaining capacity of the battery of the mobile robot using the power consumption of the battery which is a predictable parameter that is constantly reduced with the change of time,

In order to correct the power consumption rapidly changing according to the motion of the mobile robot, the power consumption pattern is derived to easily predict the appropriate charging time,

The present invention provides a method of detecting a battery level of a mobile robot that can efficiently respond to deterioration of a battery by predicting a change in battery capacity due to continuous charging and discharging based on accumulated data of a power consumption pattern.

According to an aspect of the present invention, there is provided a method of detecting a remaining battery amount according to power consumption of a mobile robot, the method comprising: a sampling time setting step of fully charging a battery and setting a predetermined sampling time and a sampling frequency; When the battery is discharged according to the motion of the robot, the sensor repeats the sampling frequency set at the sampling time interval set in the sampling time setting step, and measures the discharge current and voltage, and temporarily stores the data in the buffer. Measuring step; A power pattern calculation step of calculating a pattern of power consumption in a program storage unit by using the current and voltage data temporarily stored in the current and voltage measurement step and storing it in a database; And a remaining amount detecting step of calculating a remaining battery amount or an estimated operating time of the robot in the program storage unit through the stored power consumption pattern.

Here, the power pattern calculation step is preferably performed by integrating the current and voltage with respect to time for accurate battery remaining detection.

In addition, the method of detecting the remaining battery capacity of the mobile robot further includes a battery capacity calculation step of calculating the total battery capacity at the present time using the power consumption pattern data accumulated through the power pattern calculation step. It is desirable to correct the deterioration phenomenon of.

Hereinafter, a method of detecting a battery remaining amount of a mobile robot according to the present invention will be described in detail.

First, a configuration of a system to which a method of detecting a battery remaining amount of a mobile robot according to the present invention will be described with reference to FIG. 1.

As shown in FIG. 1, the mobile robot system 100 to which the method for detecting a battery level of a mobile robot according to the present invention is applied may include a battery level detection system 10, a battery 1, a protection circuit 2, and a sensor ( 3) the display unit 4, the system driving unit 5, the cooling fan 6, the fuse 7, the main switch (8).

The battery remaining amount detection system 10 includes an A / D converter 11, a buffer 12, a program storage unit 13, a control unit 14, and a database 15.

The protection circuit 2 contacts the battery 1 and stably supplies a reference voltage to the battery remaining amount detection system 10, and is configured as a circuit for protecting the battery 1 from external shock, overcharge, and overdischarge. .

The sensor 3 measures the current and voltage output from the battery 1 at a set sampling time interval and transmits the measured current and voltage to the battery remaining system 10. The sensor 3 measures current and voltage using a Hall element. And a Hall current transformer (Hall CT) for outputting an analog signal corresponding to the measured current and voltage. In addition, it is programmed to stop the current and voltage measurements when the set sampling frequency is reached.

The display unit 4 may display the battery remaining data calculated by the control unit 13 of the battery remaining amount detection system 10 based on the current and voltage values measured by the sensor 3. It is composed.

The system driving unit 5 controls other parts of the mobile robot system 100 other than the battery remaining amount detection system 10 for driving the mobile robot based on the information on the remaining battery level received from the battery remaining amount detection system 10. System.

The cooling fan 6 cools heat that may be generated by charging and discharging of the battery 1 based on a control signal of the battery remaining amount detection system 10 to deteriorate and charge / discharge efficiency of the battery 1 due to temperature rise. To prevent degradation.

The fuse 7 prevents overcurrent from being transferred to the battery 1 by the disconnection or short circuit of the battery 1. That is, when an overcurrent occurs, the fuse 7 is disconnected to block the overcurrent from being transmitted to the battery 1.

The main switch 8 turns on and off the battery 1 based on a control signal of the battery remaining amount detection system 10 or the system driver 5 when an abnormal phenomenon such as overvoltage, overcurrent, high temperature occurs.

The A / D converter 11 of the battery level detecting system 10 converts an analog signal of current and voltage measured by the sensor 3 into a digital signal, and converts the converted signal into a buffer 12 which is a temporary storage device. To pass.

The program storage unit 13 stores a program in the form of firmware, and calculates the power consumption pattern of the mobile robot and the charge capacity of the battery based on the signal received from the buffer 12 as the program, and optimizes the battery. It derives a charging time and delivers it to the control unit 14 and the database 15.

The control unit 14 performs a command for charging and discharging the battery based on the data received from the program storage unit 13.

The database 15 is a means for storing data transmitted from the program storage unit 13, and may be configured as an EEPROM as a nonvolatile storage device that stores the data even when the power is cut off and that can be electrically written and erased. .

Next, a method of detecting a battery remaining amount of a mobile robot according to the present invention will be described with reference to the accompanying drawings.

2 is a flowchart illustrating a method of detecting a battery level of a mobile robot according to the present invention.

As shown in FIG. 2, the method for detecting the remaining battery level of the mobile robot according to the present invention includes a sampling time setting step S10, a current and voltage measuring step S20, a power pattern calculating step S30, and a battery capacity calculating step ( S40), and the remaining amount detection step (S50).

First, in the sampling time setting step (S10), the sampling time means the measurement time interval for the current and voltage output from the battery, and the sampling frequency that means the number of times of the repeated number of current and voltage measurement repeated in the sampling time interval user The setting information is transmitted to the sensor 3 by setting at a terminal (not shown).

As shown in Fig. 3, the discharge current I and the discharge voltage V are measured at each sampling time indicated by t arranged at equal intervals, and when i is the number of sampling, the i th sampling time t _i It can be seen that the i-th discharge current (I _i ) and the discharge voltage (V _i ) are respectively measured at. Therefore, when the number of samplings is set by _n , the discharge current and the discharge voltage in the sampling period of t ₁ to t _n are measured as I ₁ to I _n and V ₁ to V _n , respectively.

Here, the sampling time (t) and the number of samplings (n) are preferably set to be applied to the system to be used under optimum conditions. For example, if the motion change of the mobile robot is large and the power change with time is large, it may be desirable to shorten the sampling time. If the repetition period of the mobile robot movement is long, the sampling frequency is set a lot. It would be desirable.

Next, the current and voltage measuring step S20 is applied after the motion of the robot is started and the battery starts to be discharged. In the sampling time setting step S10, the sensor 3 receiving the information of the sampling time and the sampling frequency is received. When the discharge of the entire mobile robot system 100 starts, it is performed by measuring and storing the current and the voltage by the sampling frequency at the set sampling time interval.

As shown in Figure 2, the current and voltage measurement step (S20) is a motion start step (S21), the sampling frequency increase step 22, the sampling time reaching step (S23), the measurement and storage step of the current and voltage (S24), a check is made whether or not the set sampling frequency has been reached (S25).

In detail, when the robot starts motion and discharge of the battery is started (S21), the sensor 3 increases the sampling frequency by one by one (S22), and when the set sampling time is reached (S23), the sensor 3 Measures the current and voltage of the sampling time present, and transfers the measurement data to the A / D converter 11, the A / D converter 11 converts the current and voltage data into a digital signal to buffer 12 Temporarily store in (S24). When the temporary storage step S24 is completed, the sensor 3 determines whether the current sampling number is the same as the sampling number set in the sampling time setting step S10 (S25), and if it is the same, further measures current and voltage. If not, go to the next step, the power pattern calculation step (S30), otherwise, go back to the sampling frequency increasing step (S22), and store 1 more counts in the current number of sampling and store the same number as in the above steps (S23 to S25). Repeat the process.

Referring to the current and voltage measurement step S20 with the graph shown in FIG. 3, after the discharge of the battery is started (t = 0), the sampling count is counted as 1, and the sampling time setting step S10 is set. it reaches a first sampling time (t _1), at the time of reaching the sampling time (t ₁₎ a current value (I ₁₎ and a voltage value (V ₁₎ is measured by the sensor 3, the current and voltage measurement data Is stored in the buffer 12. Next, the number of sampling is incremented from 1 to 2 and counted. When the second sampling time t ₂ is reached, I ₂ and V ₂ are measured and stored. Repeating the above process to reach the initially set sampling frequency n to measure In and Vn to move to the next step in the current and voltage measurement step (S20).

In the power pattern calculation step S30, the power storage pattern is calculated and stored in the database 15 by using the current and voltage measurement data temporarily stored in the current and voltage measurement step S20. to be.

Since a mobile robot often consumes a large amount of power by motion at a specific time, it is difficult to easily predict the charging time. For example, FIG. 4 shows a pattern of power consumption in a mobile robot. As shown in FIG. 4, since power consumption is not constant over time, charging time is taken into consideration only on average power consumption. It is difficult to cope with the case where the mobile robot uses a large amount of power rapidly.

Therefore, if the power consumption pattern of the mobile robot periodically moving within a certain working time is stored, this problem can be solved. In the present invention, a method of calculating and storing a power consumption pattern of a predetermined time is used.

As shown in FIG. 4, when tn is a working cycle of a specific mobile robot, when the sampling time and the number of sampling times are set to correspond to the sampling time setting step S10, the pattern of power consumption P is determined. The same pattern will be drawn with tn. Here, any of the power consumption of the sampling time t _i P _i will be obtained a formula of said derived V _i, I _i and corresponding to _{P i = V i x I i} .

The remaining amount detecting step (S50) is a step of calculating the expected operating time of the charging time or the robot from the calculated power consumption pattern.

First, t _p shown in FIG. 4 is a time point at which the battery is completely discharged. Therefore, in the power consumption pattern graph, from t = 0 (full charge point) to t = t _p (complete discharge point) It is possible to obtain the battery capacity expressed by the amount of power K (kWh or Wh) by the integral of the power P as follows.

(kW-h), Total amount of battery power (K) =

(kW-h),

(kW-h) <수학식 1>Converging the sampling time to zero, K =

(kW-h) <Equation 1>

On the other hand, the total sampling time obtained by multiplying the sampling time interval by the sampling frequency, that is, the amount of power K 'consumed up to the working cycle tn of the mobile robot, will be derived by the following equation.

(kW-h),Power Consumption to Working Cycle (K ') =

(kW-h),

(kW-h) <수학식 2>Converging the sampling time to zero, K '=

(kW-h) <Equation 2>

The total amount of power K of the battery derived from Equation 1 is an area filled with dots in FIG. 4, and the amount of power consumed K 'to the work cycle derived from Equation 2 is represented by the shaded area in FIG. 4. . Therefore, it is possible to infer the remaining battery capacity by comparing K and K ', and by analyzing the pattern shape of the power consumption at which point the power consumption increases and decreases, the optimum battery charging time can be derived. .

In addition, the method for detecting the remaining battery level of the mobile robot according to the present invention may further include a battery capacity calculation step (S40) after the power pattern calculation step (S30).

The battery capacity calculation step S40 is performed by calculating the battery capacity at the present time using the data when the power consumption pattern data calculated by the power pattern calculation step S30 is accumulated in the database 15.

As shown in FIG. 4, according to the repetition and time elapse of the battery charging and discharging, the full discharge time was initially tp and then gradually decreased to tp 'and tp' 'due to continuous charge and discharge. The decrease in time means the degradation of the secondary battery.

In FIG. 5, the discharge capacity of the battery represented by the amount of power kW-h decreases as the battery continues to be charged and discharged for a long time.

The battery capacity calculation step S40 is performed in order to accurately calculate the charging time point in consideration of the reduction of the battery discharge capacity due to the battery degradation. This is a step of inferring the battery capacity at the present time based on the accumulated power consumption pattern data of the battery through the process of detecting the remaining battery charge from the battery charge and discharge process several times.

Specifically, the graph shown in FIG. 5 using the firmware stored in the program storage unit 13 shows the tendency of the full discharge time to be shortened from tp to tp ', tp' 'as shown in FIG. 4 through several charging and discharging processes. It is possible to estimate the discharge capacity of the battery at this time by implementing the equation and deriving the governing equation of the graph.

 The more efficient charging time may be derived by using the discharge capacity of the battery at this time and the power consumption pattern of the battery derived in the power consumption calculation step (S30).

The scope of the present invention is not limited to the above embodiments, and may be embodied in various forms of embodiments within the scope of the appended claims. It will be understood that those skilled in the art to which the invention pertains may fall within the scope of the claims without departing from the gist of the invention as claimed in the claims.

As described above, according to the method of detecting the remaining battery level of the mobile robot according to the present invention, it is possible to easily predict the remaining battery capacity of the mobile robot by using the power consumption of the battery, which is a predictable parameter that is constantly reduced with time. There is,

In order to correct the power consumption rapidly changing according to the motion of the mobile robot, the power consumption pattern can be derived to easily predict the appropriate charging time or operating time of the mobile robot.

Based on the accumulated data of the power consumption pattern, it is possible to predict the change in battery capacity due to continuous charging and discharging, and to effectively cope with the deterioration of the battery.

Claims (3)

In the battery level detection method of the mobile robot, A sampling time setting step of fully charging the battery and setting a predetermined sampling time and sampling frequency; When the battery is discharged according to the motion of the robot, the sensor repeats the sampling frequency set at the sampling time interval set in the sampling time setting step, and measures the discharge current and voltage, and temporarily stores the data in the buffer. Measuring step; A power pattern calculation step of multiplying the current and voltage temporarily stored in the current and voltage measurement step, converging a sampling time to 0, and integrating the product of the current and voltage over time to calculate a pattern of power consumption and store it in a database. Wow; Computing the total battery capacity at the present time using the power consumption pattern data accumulated through the power pattern calculation step, and implements a graph of the trend of shortening the complete discharge time through a plurality of charge and discharge process, A battery capacity calculation step performed by deriving a governing equation; The program storage unit calculates the remaining battery capacity and the estimated operating time of the robot through the stored power consumption pattern and the total battery capacity of the current time, and totals the total battery capacity of the current time, multiplied by the sampling time and the sampling frequency. And a remaining amount detection step of measuring the remaining amount of battery by comparing the amount of power consumed during the sampling time, and detecting an expected operating time of the robot by analyzing the shape of the pattern of the consumed power. Battery level detection method of the mobile robot. delete delete

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