KR102648483B1 - Method of correcting current flowing through a plurality of power switches embedded in a vehicle junction box - Google Patents

Abstract

The present invention utilizes a simulator to measure the current flowing through each power switch inside the junction box, and then stores the corrected current value, which corrects the error with the actual current flow, in the memory of the junction box, to be mounted on the vehicle. It relates to a "method for correcting current flowing in a plurality of power switches built into a junction box for a vehicle and a junction box using the same" that allows the vehicle's ECU to receive the corrected current value through the junction box.
The method for correcting the current flowing in a plurality of power switches built into a vehicle junction box, which is the first embodiment of the present invention,
(a) preparing a junction box containing a computer terminal, a simulator controlled by the computer terminal, an electronic load that conducts a certain current, and 1 to n (n is a natural number greater than 1) power switches;
(b) turning on the i-th power switch (i is from 1 to n) by the simulator and connecting the i-th power switch to the electronic load in series;
(c) sequentially inputting different input current values to the electronic load six times;
(d) transmitting each current measurement value, which is the output current value flowing through the ith power switch connected in series with the electronic load, to the computer terminal;
(e) generating a predetermined current correction equation in the computer terminal and storing it in the memory of the junction box;
(f) repeating steps b through e for each of the n power switches,
The current correction function equation is
and
Each of the six input current values input to the electronic load and each of the six current measurements output from the power switch are configured as x and y coordinates, and then substituted into the current correction function to obtain the variables a, b, c, and d. , e, and f are obtained, and then the corresponding current correction function is stored in the memory of the junction box.
When implementing the method of correcting the current flowing in a plurality of power switches built into a vehicle junction box proposed by the present invention and the junction box using the same, the correction current function equation for each power switch of the junction box is stored in the memory, so the power switch Despite differences in current characteristics for each product, stable operation is possible because a current value corrected to a current value corresponding to the actual current supplied from the vehicle voltage source can be provided to the vehicle ECU.

Description

{Method of correcting current flowing through a plurality of power switches embedded in a vehicle junction box}

The present invention relates to a method for correcting the current flowing through a plurality of power switches built into a vehicle junction box and a junction box using the same. The current flowing through each power switch inside the junction box is measured using a simulator, and then the actual flowing current is measured. The "vehicle junction box" allows the vehicle's ECU to receive the corrected current value through the junction box by allowing the vehicle to be equipped with a junction box that stores the corrected current value corrected for the error in the junction box's memory. It relates to “a method for compensating current flowing through a plurality of built-in power switches and a junction box using the same.”

Generally, vehicle electrical devices are connected to an electronic control unit (ECU), and a junction box is used as an intermediary to connect the ECU and the electrical device.

Junction boxes, which are generally installed in the engine room and interior of a vehicle, are devices that supply and distribute battery power to multiple electrical devices, including vehicle lamps, various electrical components, multimedia devices, and motor drives. It functions to supply power from the battery to the back, and this junction box has a plurality of power switches built into it.

However, because each of these power switches has slightly different resistance values, different currents often flow to the same voltage source.

For this reason, the vehicle's ECU connected to the power switch may generate an error due to the current error in the power switch.

Therefore, it is necessary to compensate for differences in current flowing through the power switch for each product.

In other words, power switches used inside a junction box do not have a current measurement function, or even if they do, the error deviation is very large, so an IC dedicated to current measurement is additionally installed to precisely measure the amount of current used.

However, if additional ICs dedicated to current measurement are installed, product price competitiveness decreases.

In other words, if you add an IC dedicated to measuring current for each power switch in the junction box, there is a problem that the PCB material cost increases by about 5 to 10%.

Figure 1 is a diagram showing an example of measuring the current flowing through each power switch when a predetermined constant current is input to each of the power switches (for example, three) built into the junction box.

In Figure 1, the horizontal axis represents the current value applied to the power switch, and the vertical axis is a graph showing the current measurement value applied to each power switch.

For example, if the input current is 5A, the measured current flowing through each power switch must be 5A, but as can be seen from the graph, it can be measured as, for example, 6A or 4A.

1. Patent application number 10-2009-0000330, title of invention: Junction box for automobiles 2. Patent application number 10-2018-0012328, title of invention: Junction box for vehicles

The present invention uses a computer terminal and a simulator to flow a plurality of currents to each power switch in a junction box, then receives the actual measured current flowing in each power switch to the computer terminal, and then corrects it using a predetermined correction function equation. The purpose is to enable the junction box stored in the junction box's memory to be mounted on a vehicle.

That is, in the present invention, a junction box is installed in the vehicle by using a simulator to measure the current flowing through each power switch inside the junction box and then storing the corrected current value that corrects the error with the actual flowing current in the memory of the junction box. We would like to propose a "method for correcting the current flowing in a plurality of power switches built into a vehicle junction box and a junction box using the same" that allows the vehicle's ECU to receive the corrected current value through the junction box by allowing it to be mounted.

The method for correcting the current flowing in a plurality of power switches built into a vehicle junction box, which is the first embodiment of the present invention,
(a) preparing a junction box containing a computer terminal, a simulator controlled by the computer terminal, an electronic load that conducts a certain current, and 1 to n (n is a natural number greater than 1) power switches;
(b) turning on the i-th power switch (i is from 1 to n) by the simulator and connecting the i-th power switch to the electronic load in series;
(c) sequentially inputting different input current values to the electronic load six times;
(d) transmitting each current measurement value, which is the output current value flowing through the ith power switch connected in series with the electronic load, to the computer terminal;
(e) generating a predetermined current correction equation in the computer terminal and storing it in the memory of the junction box;
(f) repeating steps b through e for each of the n power switches,
The current correction function equation is
and
Each of the six input current values input to the electronic load and each of the six current measurements output from the power switch are configured as x and y coordinates, and then substituted into the current correction function to obtain the variables a, b, c, and d. , e, and f are obtained, and then the corresponding current correction function is stored in the memory of the junction box.

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When implementing the method for correcting the current flowing in a plurality of power switches built into a vehicle junction box proposed by the present invention and the junction box using the same, the correction current function equation for each power switch of the junction box is stored in the memory, so the power switch Despite differences in current characteristics for each product, stable operation is possible because a current value corrected to a current value corresponding to the actual current supplied from the vehicle voltage source can be provided to the vehicle ECU.

Figure 1 is a diagram showing an example of measuring the current flowing through each power switch when a predetermined constant current is input to each of the power switches (for example, three) built into the junction box.
Figure 2 is a configuration diagram for implementing a method for correcting current flowing in a plurality of power switches built into a vehicle junction box proposed in the present invention.
Figure 3 is a diagram showing current measurements compared to six input currents for one power switch.
Figure 4 is a diagram explaining a method of obtaining the variables of the correction current function equation according to the present invention.
Figure 5 is a graph before correction of the output current compared to the input current of the power switch.
Figure 6 is a graph after correction in which the current correction function equation is applied according to the present invention.

Hereinafter, with reference to the drawings, a method for correcting current flowing in a plurality of power switches built in a junction box for a vehicle, which is a technical idea proposed by the present invention, and a junction box using the same will be described.

Figure 2 is a configuration diagram for implementing a method for correcting current flowing in a plurality of power switches built into a vehicle junction box proposed in the present invention.

As shown in FIG. 1, in order to implement the present invention, a computer terminal (PC) and a simulator are prepared, and then a junction box (SJB: smart junction box) to be tested is connected to the simulator and computer terminal as shown in the drawing.

In the present invention, the simulator includes a control unit (CONTROL), a demux (DeMUX), a plurality of relays (Relay1,...Relay12) linked to the demux, and a relay (Relay).

As shown, the junction box includes a plurality of power switches (IPS1,...IPS12), a control unit (MCU), and memory (MEMORY).

Meanwhile, in order to implement the present invention, a power supply (voltage source) and an electronic load are further provided.

Here, an electronic load is a device that allows you to use the desired load. It is similar to a variable resistor, but it is a device that can use a variety of loads such as AC, DC, inductor load, and capacitor load, and the same current as the current input from the power supply flows.

Hereinafter, a method of measuring and correcting the current value flowing through each power switch in the junction box will be described with reference to FIG. 2.

First, the simulator is controlled from a computer terminal (PC) to operate relay and demux.

The operation is as follows: Turn on the relay in the OFF state and turn on the relay in the OFF state (Relay 1).

The reason for turning on the relay is to connect the power supply (voltage source) to the junction box, and the reason for turning on the relay (Relay 1) is to connect the junction box and the electronic load.

Next, the computer terminal (PC) controls the junction box to turn on a specific power switch (for example, IPS1) that is in the OFF state.

Therefore, the power supply, relay, power switch (IPS1), relay (Relay 1), and electronic load are connected in series.

Next, the computer terminal (PC) controls the electronic load so that current flows sequentially, for example, up to 1A, 2A, 3A, 6A, 10A, and 11A.

Since it is connected in series, the current measurement at the power switch (IPS1) should ideally be 1A, 2A, 3A, 6A, 10A, and 11A, but the actual measurement has errors, and the actual current measurement with these errors must be measured at the junction box. The control unit (MCU) transmits it to the computer terminal (CAN communication).

Next, the computer terminal (PC) compares the actual current value flowing to the electronic load and each current value measured at the power switch (IPS1) to calculate the constant value required for the current correction function equation.

Next, the derived constant value is transmitted from the computer terminal (PC) to the control unit (MCU) of the junction box (SJB), and this is stored in the memory (MEMORY) of the junction box.

Below, a detailed description will be given of how the computer terminal (PC) calculates the constant value required for error feedback logic by comparing the actual current value flowing to the electronic load and each current value measured at the power switch (IPS1). It will be explained as follows.

First, in the present invention, since one junction box contains 12 power switches (also known as power switch ICs), different currents are set in the electronic load 6 times, the 6 currents flowing through each power switch are measured, and then the computer The terminal calculates a predetermined 5th-order equation and performs current correction.

In the case of the present invention, since it is difficult to derive current measurements for all current values flowing through each power switch, only the output current values for the six input currents are checked, and then an arbitrary output current equation is implemented with a 5th-order simultaneous equation to obtain a current correction function. applied.

The 5th order simultaneous equation calculation method implemented in the present invention is as follows.

First, the computer terminal uses the equation below and the six coordinates to find the unknown of the equation.

The calculation can use matrix equations to calculate the six unknown variables a, b, c, d, e, and f.

For reference, the six coordinates represent the current measurement value of the power switch when a random input current is applied.

The matrix calculation formula is XZ=Y -> Z=X'Y and is as follows.

For example, as shown in FIG. 3, the output current for six input currents for one power switch is measured.

The computer terminal calculates a fifth-order equation using the six points shown in the graph of FIG. 3.

The equation is , and the coordinates are (1,0.84), (2,1.76), (3,2.73), (6,5.5), (10,10.5), and (11,11.5).

Next, calculate the variables a, b, c, d, e, and f with the six coordinates.

The calculation scheme is shown in Figures 3 and 4.

That is, the current correction function equation of the present invention is

and

Each of the six input current values input to the electronic load and each of the six current measurements output from the power switch are configured as x and y coordinates, and then substituted into the current function equation to obtain the variables a, b, c, d, After e and f are obtained, the corresponding current correction function equation is stored in the memory of the junction box.

The method of implementing the above-mentioned current compensation function is explained again as follows.

1. Input current measurement: Use an electronic load to flow the desired input current.

2. Output current measurement: The current measurement value, which is the output current value measured from each power switch in the junction box, is transmitted to the computer terminal.

3. Calculate the current correction function at the computer terminal.

4. The computer terminal stores the current correction function in the memory of the junction box through communication with the junction box.

5. Finally, use a simulator to verify whether the current compensation function applied to the memory of the junction box operates normally.

Therefore, when the junction box of the present invention is mounted on a vehicle, when a predetermined current flows through each power switch of the junction box, the memory of the junction box can accurately calculate the actual input current value using the current correction function equation for the corresponding current. .

Next, the power switch characteristics of the junction box corrected according to the present invention will be described with reference to FIGS. 5 and 6.

Figure 5 is a graph before correction of the output current compared to the input current of the power switch, and Figure 6 is a graph after correction to which the current correction function according to the present invention is applied.

From Figures 5 and 6, it can be seen that equations for all sections requiring current measurement can be implemented with six coordinates for each power switch.

Therefore, the current measurement measured at each power switch of the junction box can be substituted into the equation and the input current value can be inverted to accurately calculate.

As can be seen from the above, in the present invention, each current measurement output from the power switch is measured and implemented as an equation, and then the current correction function formula that corrects the output current error value compared to the input current according to the equation is stored in the memory of the junction box. By placing it in the vehicle and operating normally, the current measurement measured by each power switch can be substituted into the equation, the input current value can be inverted, and the input current value can be accurately calculated and transmitted to the vehicle ECU.

In the case of the present invention, since there are 12 power switches in the junction box, 72 current measurements are made by applying different currents to each power switch 6 times, and this is done automatically by the computer terminal controlling the simulator, etc.

When implementing the current correction method flowing through a plurality of power switches built into a vehicle junction box and the junction box using the same proposed in the present invention described above, the current correction function equation is stored in the memory for each power switch of the junction box. Despite differences in current characteristics of each power switch product, stable operation is possible because a current value corrected to a current value corresponding to the actual current supplied from the vehicle voltage source can be provided to the vehicle ECU.

Claims (2)

A method of correcting the current flowing through a plurality of power switches built into a vehicle junction box, comprising:
(a) preparing a junction box containing a computer terminal, a simulator controlled by the computer terminal, an electronic load that conducts a certain current, and n (n is a natural number greater than 1) power switches;
(b) turning on the i-th power switch (i is from 1 to n) by the simulator and connecting the i-th power switch to the electronic load in series;
(c) sequentially inputting different input current values to the electronic load six times;
(d) transmitting each current measurement value, which is the output current value flowing through the ith power switch connected in series with the electronic load, to the computer terminal;
(e) generating a predetermined current correction equation in the computer terminal and storing it in the memory of the junction box;
(f) repeating steps b through e for each of the n power switches,
The current correction function equation is
and
Each of the six input current values input to the electronic load and each of the six current measurements output from the power switch are configured as x and y coordinates, and then substituted into the current correction function to obtain the variables a, b, c, and d. , e, and f, and then storing the corresponding current correction function equation in the memory of the junction box.
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