JPH10170616A - Checking method for residual amount of vehicular secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a checking method which can accurately detect initial residual amount of electrical vehicular secondary battery during stopping of the motor such as before driving. SOLUTION: The method is to check for residual amount of the secondary battery of a vehicle which has a secondary battery 29 for supplying power to its driving motor, a main switch 22 which turns on or off the power supply, and an indication lamp 23 which indicates residual amount of the secondary battery. When the main switch 22 is turned on in stopping condition of the motor, micro-current is passed through the motor, voltage of the secondary battery 29 is measured while the micro-current flows, residual amount of the secondary battery is calculated based on the detected voltage, and lighting of the indicating lamp 23 is controlled according to the secondary battery.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for checking the remaining amount of a secondary battery for a vehicle, and more particularly to checking the initial remaining amount of a battery of an electric assisted bicycle equipped with an alkaline secondary battery such as a nickel-cadmium battery before starting. It is about the method.

[0002]

2. Description of the Related Art In an electric vehicle such as an electric bicycle, a rechargeable nickel-metal battery is used as a power source battery for driving the motor.
A secondary battery including a cadmium storage battery is used.
In such an electric vehicle, a pilot lamp is provided to check the remaining amount (remaining capacity) of the battery during traveling, and a detection circuit in the controller detects the voltage of the battery, and based on the detected voltage, The remaining amount (capacity) is calculated, and the warning light is displayed by lighting or blinking the pilot lamp. In this case, the voltage of the battery is detected in a state where a load is applied to the motor while the vehicle is running and a load current is flowing, and a map of a database of a voltage corresponding to the load current created in advance is used based on the detected voltage. To calculate the remaining battery power.

On the other hand, there is a case where it is desired not only to check the remaining amount of the battery while the vehicle is running, but also to check the remaining battery level before or after the running. In such a case, it is possible to detect the battery voltage by the detection circuit in the controller described above and calculate the remaining amount based on the detected battery voltage.

[0004]

However, due to the characteristics of alkaline batteries such as nickel-cadmium batteries, the relationship between the remaining amount and the voltage can be accurately calculated when the load current is flowing as described above. In the open voltage state where no current flows, it cannot be calculated accurately. This is because in the case of nickel-cadmium batteries, the open-voltage characteristics drop slightly immediately after starting use of the battery, irrespective of the remaining battery capacity, and then maintain a nearly constant voltage until the battery reaches its end of life. This is because the voltage drops sharply. That is, the open voltage is almost constant during the use period regardless of the remaining amount of the battery, the change with the use time is small, and even if the open voltage is detected, the remaining amount is accurately calculated from the value. I can't.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and is directed to a method for confirming the remaining amount of a secondary battery for an electric vehicle which can accurately detect the initial remaining amount of the battery when the motor is stopped before running the vehicle. For the purpose of providing.

[0006]

In order to achieve the above object, according to the present invention, there is provided a secondary battery for a power source of a vehicle drive motor, a main switch for turning on and off the power source, and a control unit for controlling a remaining amount of the secondary battery. A method of checking the remaining amount of the secondary battery in a vehicle, comprising: a display lamp for performing a display indicating that a small current is supplied to the motor when the main switch is turned on from a stopped state of the motor; Measuring the voltage of the secondary battery, calculating the remaining amount of the secondary battery based on the detected voltage, and controlling lighting of the display lamp according to the remaining amount. Provide a method for checking the remaining battery level.

According to this configuration, since the voltage is detected in a state where a minute current flows, regardless of the open voltage when the motor is stopped, an accurate remaining amount can be detected, and the initial remaining amount (capacity) before traveling can be determined. It can be measured and displayed on a display lamp according to the remaining amount. In this case, the minute current is a small current that does not cause the vehicle to run or vibrate.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a preferred embodiment,
During the calculation of the remaining amount of the secondary battery, by the display lamp,
It is characterized in that the display during the battery remaining amount check is performed by a specific lighting pattern different from the remaining amount display pattern.

According to this configuration, during the confirmation of the initial capacity, the display lamp is turned on in a specific pattern (for example, by blinking three LEDs repeatedly in order), and the user is confirming the remaining battery level. Can be recognized. Since this display pattern is a special pattern different from the remaining amount display pattern, the user does not mistakenly recognize it as the remaining amount display, and when the user “remains sufficient amount” or “there was a remaining amount initially, Will soon disappear. " In addition, by turning on the display lamp during the initial remaining amount check, it is checked whether the lamp operates normally.

In a further preferred embodiment, in the driving state of the motor, the load current of the motor is calculated without flowing the minute current, and based on the load current and the detected voltage of the secondary battery at this time. It is characterized in that the remaining amount of the secondary battery is calculated, and the lighting of the display lamp is controlled according to the remaining amount.

According to this configuration, when the motor is driven while the vehicle is running, a load current to the motor is calculated, and an accurate remaining battery level during running is calculated based on the load current and the battery voltage at this time. In addition to the above-mentioned initial remaining amount, the battery remaining amount can always be accurately measured and displayed.

[0012] In a further preferred embodiment, the secondary battery is a nickel-metal hydride battery mounted on a battery-assisted bicycle.
It is characterized by being a cadmium battery.

As described above, by using the present invention as a method for checking the remaining amount of a nickel-cadmium battery as a battery of an electric assisted bicycle, the remaining battery amount before or after using the electric assisted bicycle can be accurately confirmed. In addition, charging and the like can be performed as needed, and usability is improved.

[0014]

FIG. 1 is a side view of an electric assisted bicycle according to the present invention. The electric assisted bicycle 1 includes a head pipe 4 for holding a steering shaft 3 of a steering wheel 2 and a main pipe (not shown) joined rearward and downward to the head pipe 4. The main pipe is covered with a frame cover 5. Have been done. A resultant unit 6 is provided at the rear end of the main pipe in the center of the vehicle. The resultant unit 6 combines the pedaling force from the pedal 7 and the auxiliary power of the motor 8 to drive the rear wheel 14 via the chain 13. A battery housing 9 is formed below the saddle 11, and a detachable battery box 28 is housed inside. A controller 10 is provided behind the resultant mechanism 12 including the pedal crankshaft. The controller 10 controls the driving of the motor 8 based on detection signals from a vehicle speed sensor and a pedaling force sensor (both not shown) provided around the pedal crankshaft.

A switch box (not shown) covered with a switch cover 17 is provided on the main pipe at the junction between the head pipe 4 and the main pipe at a position that is easy for a driver to see while traveling. The switch box includes a main switch (not shown) for turning on and off the power supply from the battery to the motor 8 and the controller 10, and further includes a plurality (for example, three) of LEDs for indicating the remaining battery level. This switch box is connected to the controller 10. The controller 10 calculates the remaining battery level based on the operation of the main switch and a voltage detection circuit (not shown) in the controller as described later,
Display by

FIG. 2 is a block diagram of a battery remaining amount detection circuit applied to the electric assist bicycle of FIG. The main switch 22 is mounted in the switch box 21 and 3
Two battery remaining amount display LEDs 23 are provided. The switch box 21 is connected to the controller 10 via a total of five lines including three lines connected to the LED and two main switch lines having, for example, the (+) side common to the LED.
Connected to. The controller 10 is further connected with a motor 8, a vehicle speed sensor 25, a pedaling force sensor 26, and a battery 29 housed in a battery box 28. As will be described later, the controller 10 includes an arithmetic processing circuit including an arithmetic processing program for calculating the remaining amount of the battery 29 and displaying the remaining amount on the LED, and a database necessary for performing the remaining battery amount calculation. And a circuit for outputting a weak current, a battery voltage detection circuit, and the like.

FIG. 3 is a flowchart showing a sequence of a process for detecting and displaying the initial battery remaining amount by the battery remaining amount detecting circuit of FIG. First, the main switch is turned on by the user (driver) of the battery-assisted bicycle (step S).
1). Subsequently, it is determined whether or not the bicycle is running based on the detection data of the vehicle speed sensor and the treading force sensor (step S2). In this case, running is a state in which the vehicle speed has a certain value and the pedaling force is detected (in the case of a general electric vehicle, the accelerator means is driven).
In addition, the case where the vehicle is not traveling refers to a case where the vehicle speed is zero and a state where the pedaling force is not detected at the time of coasting or the like, that is, a state where the load on the motor is zero. If the vehicle is not running, the process proceeds to step S3, and a timer for detecting the initial remaining amount is started. The timer time is, for example, 1 second. That is, after the power is turned on by the main switch, the initial remaining amount of the battery before the motor drive is started is detected as follows during this timer time.

At the same time as the timer starts, three LEs
By flashing D in a predetermined pattern, for example, in order, the user is notified whether the initial capacity is being checked. By performing this operation, it can be confirmed at the same time that the LED is normal.

When the timer starts, a minute current is first output from the circuit in the controller to the motor (step S4). This minute current is a current that does not cause the vehicle to run or causes no vibration, for example, about 0.5 A. Next, the battery voltage is detected in a state where the minute current is applied (step S5). Subsequently, step S6
, The remaining amount of the battery is calculated using a voltage and remaining amount map provided in the controller in advance based on the detected voltage. As described above, by detecting the voltage in a state where the current is forcibly supplied to the motor when the motor is stopped, it is possible to calculate an accurate remaining battery level based on the detected voltage. This battery remaining amount calculation routine is repeated for a timer time (for example, 1 second). In this case, since the voltage is unstable immediately after the motor is energized, the maximum or minimum value, the intermediate value or the average value, or the timer end of the remaining battery operation value obtained within this timer time is calculated. A program is created so as to sometimes output the closest last data as a calculation result of the initial battery remaining amount.

When the timer time (1 second) has elapsed (YES in step S7), the controller responds to the remaining battery charge based on the calculation result of the initial battery remaining charge before starting the motor drive obtained as described above. Then, the three LEDs are appropriately selected, turned on or blinked, and the remaining amount is displayed on the switch box (step S11). Next, in step S12, it is determined whether to stop discharging when the remaining battery level is low. If the remaining battery power is insufficient to the extent that traveling is impossible, an end operation such as shutting off the power supply line from the battery to the motor, turning off the main switch circuit, turning off the pilot lamp, and the like is performed (step S14).

On the other hand, if the remaining battery level is sufficient in step S12, the discharge is continued and the motor is driven according to the normal operation program (step S13).
That is, a torque to be assisted by the motor is calculated based on the detection results of the vehicle speed sensor and the pedaling force sensor, and a driving current is supplied to the motor based on the calculated torque to perform auxiliary power traveling. During the normal operation, a load current for the motor is calculated from a database stored in a memory in advance based on the detected pedaling force value (step S8). Subsequently, the battery voltage is detected while the load current is flowing (Step S).
9). Subsequently, based on the detected voltage, the remaining battery level during traveling is calculated using a map of the remaining battery level corresponding to the load current and the battery voltage, which is created in advance and stored in the memory (step S10). In step S11, the calculated remaining battery level is the same as the initial remaining level described above.
Displayed by ED. When the remaining battery power is lower than the predetermined value, the discharge from the battery is stopped (step S12), and the operation of ending the auxiliary power motor is performed as described above (step S14). If the remaining battery level is sufficient, the normal operation described above is repeated (step S13).

On the other hand, if the vehicle is running when the main switch is turned on in step S2, for example, the vehicle is running as a normal pedaling bicycle without using a motor while pedaling with the pedals. When the main switch is turned on and the auxiliary power is used, the load current is flowing, so that the normal operation operation (steps S8 to S13) is performed without performing the above-described routine for calculating the initial remaining amount. Repeat.

In the above-described embodiment, the main switch is turned on during a light load operation such as downhill or during a slow coasting operation, and when it is determined that the vehicle is not running (step S2), the above-described operation is performed. As described above, a minute current flows through the motor. In such a case, it is conceivable that the motor driving force due to the minute current has some effect on the vehicle, such as an increase in speed. In order to cope with this, a brake detection switch is provided, and only when the main switch is turned on in a state where it is detected that the brake operation is being performed, the minute current for calculating the initial remaining amount is supplied. May be configured.

FIG. 4 shows an example of a battery remaining amount detection flow in consideration of such a braking operation. In this flow, in the flow of FIG. 3, when the determination of whether or not the vehicle is traveling in step S2 is NO, that is, when the vehicle is stopped or coasting,
It is determined whether the brake is applied (step S
15) If the brake is not applied, wait until the brake is applied (step S16). Only when the brake is applied, the timer is started to calculate the above-mentioned initial capacity. According to such a configuration, the safety at the time of starting the auxiliary power is enhanced, and as described above, the accurate initial battery remaining amount can be confirmed.

[0025]

As described above, according to the present invention, regardless of the open voltage at the time of stopping the motor, the state is such that a very small current that does not affect the vehicle operation is forced to flow to the stopped motor. Since the voltage is detected, an accurate remaining battery level can be calculated from the voltage. Therefore, it is possible to accurately measure the initial battery remaining amount while the vehicle is stopped before traveling, and display this on the display lamp. As a result, when the remaining battery level is low, as in the conventional case, the remaining voltage is displayed as “Yes” at the open voltage, and it is possible to prevent the remaining level from dropping sharply after traveling to prevent the battery level from becoming insufficient. The reliability of the quantity display is improved. Further, in this case, not only one display lamp merely indicates whether the remaining battery level is a driveable amount, but also a plurality of display lamps are used to display the remaining battery level according to the remaining battery level, and the remaining amount is displayed to the driver. The usability can be improved because the mileage can be predicted.

The present invention is not limited to the electric assist bicycle,
The present invention is applicable to other electric vehicles driven by a motor.
Further, the present invention is not limited to nickel-cadmium batteries,
It is applicable to nickel-metal hydride batteries and other alkaline secondary batteries.

[Brief description of the drawings]

FIG. 1 is a side view of an electric assist bicycle to which the present invention is applied.

FIG. 2 is a block diagram of a battery remaining power detection circuit according to the present invention.

FIG. 3 is a flowchart of a battery remaining amount confirmation display method of the present invention using the detection circuit of FIG. 2;

FIG. 4 is another flowchart of the battery remaining amount confirmation display method of the present invention using the detection circuit of FIG. 2;

[Explanation of symbols]

8: motor, 10: controller, 21: switch box, 22: main switch, 23: LED, 25: vehicle speed sensor, 26: pedal force sensor, 28: battery box, 29: battery.

Claims (4)

[Claims] 1. A secondary battery for a vehicle, comprising: a secondary battery for a power source of a vehicle driving motor; a main switch for turning on and off the power source; and an indicator lamp for displaying an indication according to a remaining amount of the secondary battery. In the remaining amount checking method, when the main switch is turned on from the stop state of the motor, a minute current is supplied to the motor, and the voltage of the secondary battery is measured in a state where the minute current is supplied. Calculating a remaining amount of the secondary battery based on the remaining amount, and controlling lighting of the display lamp according to the remaining amount. 2. The display according to claim 1, wherein during the calculation of the remaining amount of the secondary battery, the display lamp displays an indication of the remaining battery amount in a specific lighting pattern different from the remaining amount display pattern. The method for confirming the remaining amount of the secondary battery for a vehicle described in the above. 3. In the driving state of the motor, a load current of the motor is calculated without flowing the minute current, and the remaining amount of the secondary battery is calculated based on the load current and the detected voltage of the secondary battery at this time. 3. The method according to claim 1, wherein an amount is calculated, and lighting of the display lamp is controlled according to the remaining amount.
The method for confirming the remaining amount of the secondary battery for a vehicle according to the above. 4. The method according to claim 1, wherein the secondary battery is a nickel-cadmium battery mounted on a battery-assisted bicycle.