JPH08185890A - Control method for battery used as drive source for moving body - Google Patents

Abstract

PURPOSE: To make accurate judgement about the residual capacity of a battery by measuring momentary discharge current and voltage, and making a comparison between real discharge electric energy calculated via the integration of momentary discharge electric energy, and design discharge electric energy. CONSTITUTION: A mobile moving body 10 has a battery 11 mounted as a drive source, and a power feed outlet is fitted with an ammeter 13 and a voltmeter 14. Furthermore, the moving body 10 collects data signals from battery momentary discharge voltage and current as well as from a sensor mounted thereon at every prescribed time intervals, and transmits the signals from a transceiver device 17. The data signals are sent to a controller 20 via a communication device 30 and CPU 22 makes judgement about a residual discharge amount on the basis of a relationship between the design discharge depth and the life cycles of the battery 11 stored in a memory device 23. According to this construction, capacity control can be made on the basis of the preset design condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for managing a battery used as a drive source for a mobile body, and more particularly to discharge power in a battery for a mobile body using an Ni-Cd alkaline storage battery having a battery pack structure as a drive source. The present invention relates to a method for accurately performing battery capacity management and battery life management by calculating a discharge depth.

[0002]

2. Description of the Related Art Conventionally, a lead-acid battery used as a battery for a drive source of a moving body such as a robot that runs in a factory has a discharge characteristic that the voltage gradually drops even near the discharge end point. have. Therefore, when the voltage drops to a certain value, the voltage drop can be detected and charging can be performed. Regarding battery life management, time-based life management is performed on the assumption that the battery is designed to have a constant discharge depth and that discharge is performed at a constant discharge depth.

However, in recent years, in fields where the battery consumption is not constant, such as a drive source for a mobile body, it is desired to use a storage battery having a higher energy density and a relatively longer life than a lead storage battery, and a Ni--Cd type storage battery is used. The use of alkaline storage batteries is increasing.

[0004]

Then, when the discharge characteristics of the Ni--Cd type alkaline storage battery are examined, the discharge characteristics are close to the rectangular characteristics and a sharp voltage drop occurs when the discharge end point is approached. For this reason, it is difficult to determine the charging time, and sometimes the moving body cannot be self-propelled to a predetermined charging place, which may make the moving body unchargeable. In addition, assuming that the overload is repeated many times due to a sudden increase in load, or conversely, the state where the discharge depth is shallow occurs repeatedly, the discharge is at a steady discharge depth. The conventional time-based life management based on this assumption cannot perform accurate and sufficient management. The reason for this is that if over-discharging is repeated many times, the activity of the internal substances of the storage battery will decline and the life will be shortened.If the state of shallow discharge depth occurs repeatedly, the battery cell of the assembled battery This is because an imbalance occurs between them and the apparent discharge capacity decreases.

The present invention has been made in order to solve the above problems in the prior art, and its purpose is to manage the capacity of a battery and prevent discharge in any case except in an emergency. It is an object of the present invention to provide a method of managing a battery used as a drive source of a mobile body, which can accurately and sufficiently manage the life of the battery based on the amount (discharge depth).

[0006]

In order to achieve the above object, according to a first aspect of the present invention, there is provided a method of managing a battery used as a drive source for a moving body, which comprises replacing a battery or performing a single operation. Measuring an instantaneous current and an instantaneous voltage at each predetermined time interval from the time when charging is completed, calculating an instantaneous discharge power amount from the measured current and the measured voltage, and storing the calculated amount; The current actual discharge power amount is calculated by integrating the instantaneous discharge power amount from the charging to the current time, and the actual discharge power amount is calculated with respect to the design discharge power amount obtained from a predetermined design discharge depth. Comparing the electric power amounts, and in the comparison, if the actual discharge electric power amount is smaller than the design discharge electric power amount, continuing the discharge by the operation of the moving body, and in the comparison, the actual discharge electric power amount is the designed discharge electric power amount. If the amount of electricity is greater than the amount of electricity and the vehicle is operating automatically, it returns to the specified charging position to perform charging, while if the vehicle is operating manually, an alarm indicating that the discharge capacity is exceeded is issued. There is provided a battery management method comprising the following steps.

According to a second aspect of the present invention, there is provided a method for managing a battery used as a drive source for a moving body, wherein the battery replacement or one charge to the next charge is one cycle. Measuring the instantaneous current and the instantaneous voltage at each predetermined time interval from the time when the battery is replaced or once charged, and the instantaneous discharge electric energy is calculated from the measured current and the measured voltage, and Remember this,
1 obtained by integrating the instantaneous discharge electric energy
The calculation of the discharge depth for each cycle from the actual discharge electric energy for each cycle, the calculation of the average discharge depth for each cycle after repeating a predetermined number of cycles, and the calculation of the discharge depth and the number of life cycles A battery characterized by comprising respective steps of applying the average discharge depth to a graph showing a relationship to obtain a corresponding number of life cycles and calculating the number of remaining life cycles based on the obtained number of life cycles. Management methods are provided.

Further, according to the present invention, the step of calculating the remaining life cycle number according to the second aspect includes subtracting the predetermined cycle number and the preliminary cycle number from the life cycle number.

[0009]

In the battery management method of the present invention, the instantaneous discharge power is calculated by measuring the instantaneous discharge current and the instantaneous discharge voltage from the battery at predetermined time intervals of, for example, every few seconds, and the instantaneous discharge power is integrated. By doing so, the actual discharge power amount is obtained. The remaining capacity of the battery can be accurately determined by comparing this with a predetermined design discharge power amount. In addition, when one cycle from battery replacement or one charge to the next charge, after repeating a predetermined number of cycles, the average discharge depth for each cycle is calculated, and this is calculated as the discharge depth and the life cycle. The life cycle number can be obtained by applying the graph to the relationship with the number. The remaining life cycle number can be calculated by subtracting the predetermined cycle number and the preliminary cycle number up to that time from the thus obtained life cycle number. Therefore, it is possible to accurately and sufficiently manage the capacity and the life of the battery.

[0010]

The present invention will now be described in more detail with reference to the embodiments shown in the accompanying drawings.

FIG. 1 is a block diagram showing a schematic overall configuration of a system for carrying out the battery management method of the present invention. In FIG. 1, a self-propelled moving body 10 is Ni-C.
A battery 11 which is an assembled battery in which a plurality of d-type alkaline storage batteries are assembled in series is mounted as a drive source. An ammeter 13 and a voltmeter 14 are attached to a power supply outlet from the battery 11 via a switch 12 so that a discharge current and a discharge voltage of the battery 11 can be measured at any time. It is also possible to calculate (discharge current × discharge voltage). Reference numeral 15 indicates a load device including a traveling motor of the moving body 10 and a drive motor of an accessory such as a surveillance camera (not shown) attached to the moving body 10, for example.

The moving body 10 is further provided with an instantaneous discharge voltage v _i of the battery, an instantaneous discharge current a _i , and a data signal x _i from other on-board sensors for a predetermined time (for example, several seconds) t.
_It is collected for each ₀ and the transmission / reception device 17 and the separate communication device 30
CPU1 to send to the controller 20 on the fixed operation side via
6 is mounted. Reference numeral 18 indicates a charging terminal.

On the other hand, the fixed operation side controller 20 has a decoder 21 for inputting a signal from the communication device 30,
CPU2 for processing the signal decoded by the decoder
2, and at least a storage device 23 for storing the result processed by the CPU 22 and other necessary data. The storage device 23 stores in advance the specified capacity P ₀ (W × h) of the battery 11, the designed discharge depth y ₀ (%), the relationship graph between the discharge depth and the number of life cycles shown in FIG. 4, and the like. .

A signal sent from the CPU 16 on the moving body side via the transmitter / receiver 17 is the CPU 16 and the CPU 22 on the fixed operation side.
, The instantaneous discharge voltage v _i
And the instantaneous discharge power amount q _i in place of the instantaneous discharge current a _i
It can also be sent as (= a _i × v _i × t ₀ ).

In the controller 20 on the fixed operation side, the decoder 21 decodes the data signal sent from the mobile body side, and stores it in the storage device 23 as the value of each sensor.
Further, in some cases, the instantaneous discharge voltage v _i and the instantaneous discharge current a _i are sent to the CPU 22 to calculate the instantaneous discharge power amount q _i , which is also stored in the storage device 23.

As preparation for the following description, design conditions for implementing the battery management method of the present invention are set and set as follows. 1. Batteries used: Ni-Cd alkaline storage battery pack, 2.1 Designed discharge depth per cycle (y ₀ ): 40%
(0.4C), 3. Number of life cycles corresponding to the above design discharge depth: Approximately 8
300 cycles (by reading from the graph in FIG. 4).

Next, referring to the flow charts of FIGS. 2 and 3, the first and second embodiments of the present invention will be described in order below.

First, referring to FIG. 2, the capacity management of the battery 11 according to the first embodiment of the present invention will be described. Immediately after battery replacement or immediately after one charging is completed (i =
0), the instantaneous discharge current a _i and the instantaneous discharge voltage v _i are measured by the ammeter 13 at every predetermined time t ₀ (for example, several seconds).
And read by the CPU 16 on the moving body side via the voltmeter 14 (F-1).

The instantaneous discharge current a _i and the instantaneous discharge voltage v
_{From i} , the instantaneous discharge power q _i (= a _i × v _i × t ₀ ) is C
It is calculated by the PU 16 or 22 (F-2).

Further, the instantaneous discharge power amount q _i is integrated to calculate the actual discharge power amount Q _n up to the present time in by the CPU 22 (F-3).

[0021] Subsequently, the design discharge depth y ₀ and battery defined dimensioning discharge power from P ₀ be calculated quantity Q _{0
(= P 0 × y 0/} 100) the value obtained by subtracting the reserve power quantity α from (Q ₀ -α) and comparing the actual discharge electric power amount Q _n (F-
4). The reserve power amount α is a power amount for returning the moving body 10 to a charging place (not shown).

In the result of the above comparison, Q _n > Q ₀
When it is not α, the operation of the moving body 10 is continued (F-
5).

After the lapse of a predetermined time, it is judged again whether the actual discharge electric energy is to be calculated (F-6), and if it is normal (F-
Returning to 3), the operations of (F-3) and (F-4) are performed.
A series of operations at predetermined time has elapsed from (F-3) (F- 6) are repeated until Q _n> Q ₀ -α in (F-4). On the other hand, in case of emergency, the operation of the moving body 10 is further continued at the operator's discretion (F-7).

The operator repeatedly determines whether or not to recharge the mobile unit 10 during continuous operation (F-
8). In addition, when charging, it will run to the charging location and receive charging (F-10).

While the operation of the moving body 10 is further continued according to the operator's judgment, the capacity of the battery 11 is exhausted (over discharge).
Can be In that case, the moving body 10 stops on the spot and cannot run by itself. From this state, in order to allow the moving body 10 to travel again by itself,
It is necessary to carry the battery from the stopping place to the charging place by another force and charge it.

On the other hand, in the comparison of the above (F-4), Q _n
If> Q ₀ −α, it is determined whether the moving body is in automatic operation or manual operation by the operator (F-9).

During the automatic operation, the moving body 10 is returned to the charging place (not shown) to be charged (F-10).

During the manual operation, an alarm is issued to inform the operator that the discharge capacity is exceeded (F-11).

Here again, the operator is left to decide whether or not to continue the operation (F-12), and it is required to decide whether to stop the operation or continue the operation (F-13). If it is determined that the operation is stopped, the charging operation of (F-10) is performed, and when the operator determines that the emergency state cannot stop the operation of the moving body 10 and its accessory device, (F-7) ) To continue the operation.

Next, a battery life management method according to a second embodiment of the present invention will be described with reference to the flowchart of FIG.

In the following description, the battery life is indicated by the number of cycles, but one cycle of the battery means a period from battery replacement or one charging to the next charging. Therefore, when managing the life of the battery 11, the number of cycles is measured, and the cycle number is measured.
Stored in.

The battery life has a close relationship with the discharge depth in each cycle (how the battery is consumed), and as is clear from the graph of the relationship between the discharge depth and the number of life cycles shown in FIG. The number of battery life cycles is determined by the depth of discharge.

In FIG. 3, first, at the time when the first charge / discharge cycle j is completed, the actual discharge depth y in cycle j is
Calculate _j as follows. That is, as described in the above capacity management, the instantaneous discharge power amount q _i is obtained from the instantaneous discharge current a _i and the instantaneous discharge voltage v _i , and q _i in cycle j is integrated to calculate the actual discharge power in cycle j. Calculate the quantity Q _j . Using the obtained Q _j and the specified capacity P _{0 of the} battery 11, the actual discharge depth y _j in the cycle _j is calculated from the following formula (S-1).

[0034]

[Mathematical formula-see original document] y _j = Q _j / 100P _{0 Since} the way of consuming the battery 11 mounted on the moving body 10 cannot be determined only by the actual discharge depth in one cycle, the moving body 10 is further Drive m
Cycles (however, several tens cycles ≤ m ≤ 100 cycles) of battery consumption (charging / discharging) are repeated (S-
2).

The actual discharge depth of each cycle within m cycles was obtained, and these were averaged to obtain m. It is determined as the discharge depth of the battery 11 mounted on the battery 10 (S-3).

[0036]

[Equation 2] The life cycle number L of battery 11 is obtained (S-4).

Thus, the number of remaining cycle lives of the battery 11 can be obtained from Lm (S-5).

Here, even if a secondary battery such as a lead storage battery that can be reused by charging or a Ni--Cd alkaline storage battery used in the present invention is mentioned, as the life cycle number approaches 0, the electrolyte solution and Since the activity of internal substances declines and the specified capacity of the battery decreases, it is necessary to replace the battery when the remaining life cycle number reaches a predetermined life cycle number β (usually several tens of life cycle numbers). I will call you.

Therefore, also in the life management of the present invention, the remaining life cycle number (Lm) is compared with the predetermined life cycle number β (S-6), and if Lm <β, the battery is replaced. The operator is notified of the need (S-7), and the battery is replaced (S-8).

On the other hand, the comparison result of (S-6) is Lm
If> β, the operation returns to (S-1) and (S-
The remaining life cycle number is calculated by repeating the operations from 1) to (S-5). When the series of operations is repeated, the comparison result in (S-6) is Lm <β.
It is performed until it becomes.

For reference, the specific life cycle number of the Ni--Cd alkaline battery was calculated using the graph shown in FIG. 4, and the designed discharge depth was 40% (0.4
In the case of C), it can be read that the life cycle number is about 8300. Moreover, it can be read from the graph of FIG. 4 that the discharge depth in the alkaline battery when the number of life cycles is 10,000 is 35%. Usually, the designed discharge depth is between 20% and 40%.

As described above, in the battery management of the present invention, the management based on the discharge depth is performed, so that it is possible to deal with the unevenness between the cells in the assembled battery.

That is, as a characteristic of the battery pack, when the shallow discharge and the corresponding shallow charge are repeated a plurality of times, the discharge capacities become uneven among the individual cells (cells) of the battery pack. In such a state, there arises a problem that the apparent charging capacity is lowered by the normal charging method.

Therefore, when shallow charging / discharging is repeated about 10 times, the charging pressure is increased by about 1.2 times to perform charging. This charging corrects the uneven discharge capacity between cells.
This is called equal charging.

The above description is merely illustrative of the preferred embodiments of the present invention and the scope of the present invention is not limited thereto. Many more variations and modifications of the present invention will readily suggest themselves to those skilled in the art without departing from the scope of the invention.

[0046]

As is apparent from the above description, according to the present invention, the discharge electric energy (voltage × current) of the battery is measured by the voltmeter and the ammeter attached to the power supply outlet from the battery. Since the actual amount of discharge (discharge depth) can be accurately managed by integrating it, the following effects can be achieved. 1. When a Ni-Cd alkaline storage battery having a high energy density is used as a drive source for a moving body, capacity management can be performed based on preset design conditions, and charging / discharging can be appropriately performed. 2. Even when the moving body performs an operation different from the normal operation and performs a discharge different from the preset design discharge depth, it is possible to predict a decrease in life due to the discharge and perform battery state maintenance (CBM). 3. Even if the shallow discharge and the charge to compensate for it are repeated (about 10 times), the discharge depth is managed appropriately so as to correct the unevenness between the cells of the battery. By implementing the above, it is possible to prevent an apparent decrease in charge capacity.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic overall configuration of a system for carrying out the method of the present invention.

FIG. 2 is a flowchart regarding capacity management according to the first embodiment of this invention.

FIG. 3 is a flowchart relating to life management, which is a second embodiment of the present invention.

FIG. 4 is a graph showing the relationship between the discharge depth and the number of life cycles of various batteries.

[Explanation of symbols]

 10 Mobile Object 11 Battery 12 Switch 13 Ammeter 14 Voltmeter 15 Load Device 16 CPU (Mobile Object Side) 17 Transmitter / Receiver 18 Charging Terminal 20 Controller 21 Decoder 22 CPU (Fixed Operation Side) 23 Storage Device 30 Communication Device

Claims (3)

[Claims] 1. A method of managing a battery used as a drive source for a mobile body, which measures an instantaneous current and an instantaneous voltage at predetermined time intervals from the time when the battery is replaced or charged once. That the instantaneous discharge power amount is calculated from the measured current and the measured voltage, and that this is stored, and the instantaneous discharge power amount from the time after charging to the current time is integrated to obtain the current actual discharge. Calculating the amount of electric power, comparing the actual amount of discharged electric power to the amount of designed discharged electric power obtained from a predetermined designed discharge depth, and in the comparison, the amount of actual discharged electric power is the amount of designed discharged electric power If it is smaller, the discharge by the operation of the moving body is continued, and in the comparison, the actual discharge power amount is larger than the design discharge power amount, and if the moving body is automatically operated, a predetermined value is set. The method for managing a battery is characterized by comprising the steps of returning to the charging position to perform charging, and issuing an alarm of discharge capacity excess when the moving body is in manual operation. 2. A method of managing a battery used as a drive source of a mobile body, wherein when the battery replacement or one charging to the next charging is one cycle, the battery replacement or one charging is performed. Measuring an instantaneous current and an instantaneous voltage from time to time at a predetermined time interval, calculating an instantaneous discharge power amount from the measured current and the measured voltage, and storing the calculated amount; 1 from the actual discharge electric energy for each cycle obtained by integrating the electric energy
Obtaining the discharge depth for each cycle, calculating the average discharge depth for each cycle after repeating a predetermined number of cycles, and showing the average discharge depth in a graph showing the relationship between the discharge depth and the number of life cycles. A method of managing a battery, which comprises the steps of applying the above to obtain a corresponding number of life cycles and calculating the number of remaining life cycles based on the obtained number of life cycles. 3. The battery management method according to claim 2, wherein the step of calculating the number of remaining life cycles includes subtracting the predetermined number of cycles and the number of spare cycles from the number of life cycles.