KR102250290B1 - Method for improving errors of sensed current in IPS Device - Google Patents

Abstract

The present invention senses the load current of a vehicle such as a lamp using a sensing current, a leakage (offset) current, and a constant K (a value obtained by dividing the load current by the sensing current) of the IPS device so as to improve the sensing current error in the IPS device. Provides an IPS sensing current error improvement method that can control the deviation of the sensing current that occurs during operation.
The method for improving the sensing current error of the IPS device according to an embodiment of the present invention includes the steps of setting a load current by the IPS device, turning on the IPS device of each corresponding vehicle, and measuring the sensing current during a sensing time of t seconds. And turning off the IPS device of the vehicle, measuring a leakage current for a time after t seconds, and calculating a constant K using the load current, the sensing current, and the leakage current. do.

Description

Method for improving errors of sensed current in IPS Device}

The present invention relates to a method for improving an error of a sensing current of an IPS (Intelligent Power Switch) device, and more particularly, to a method for improving an IPS sensing current error capable of detecting a disconnection or a short circuit of an IPS device by reducing the error of the sensing current. will be.

In accordance with the development of electronic technology and the demands of users, vehicles are equipped with various convenience devices and safety devices, and each of these devices is operated by electronic control.

Accordingly, a fuse is mounted to protect circuits for these devices, and a relay is mounted to act as a switch for executing an operation on these devices.

However, the fuses and relays mounted on the vehicle occupy a large volume and are being replaced by small semiconductor chips, that is, an intelligent power switch (IPS), which is an intelligent power switch.

When the vehicle operates an arbitrary load, the IPS outputs a sensing current proportional to the load current.

For example, a vehicle has various types of headlights to identify road conditions and obstacles by illuminating the front during night driving and providing visual information to the driver, and tail lights to allow nearby vehicles to identify the vehicle while driving. Lamps are provided before and after the vehicle.

In order to control the load of a vehicle such as a lamp using the IPS, or to prevent damage to the wiring harness, it is necessary to improve the error of the IPS sensing current.

[Patent Document] Korean Patent Registration No. 10-0792424.

The present invention uses the sensing current, leakage (offset) current, and constant K (a value obtained by dividing the load current by the sensing current) of the IPS device so as to improve the sensing current error in the IPS (Intelligent Power Switch) device. It provides an IPS sensing current error improvement method that can control the deviation of the sensing current that occurs when sensing the load current of a vehicle.

The method for improving the sensing current error of the IPS device according to an embodiment of the present invention includes the steps of setting a load current by the IPS device, turning on the IPS device of each corresponding vehicle, and measuring the sensing current during a sensing time of t seconds. And turning off the IPS device of the vehicle, measuring a leakage current for a time after t seconds, and calculating a constant K using the load current, the sensing current, and the leakage current. do.

Also, between measuring the sensing current during the sensing time of t seconds and turning off the IPS device of the vehicle, storing the sensing current in a volatile memory.

Also, storing the leakage current in a nonvolatile memory between the step of measuring a leakage current for a time after t seconds and calculating a constant K using the load current, the sensing current, and the leakage current. It may include.

In addition, after calculating the constant K using the load current, the sensing current, and the leakage current, storing the constant K in a nonvolatile memory may be further included.

This technology is a technology that can control deviations that occur when sensing the load current of a vehicle such as a lamp.

In addition, by controlling the deviation that occurs when sensing the load current of the vehicle, this technology accurately implements the function of detecting disconnection and short circuit of the vehicle such as a lamp, so that the cost competitiveness of a smart junction box equipped with an IPS element and Quality can be secured.

1 is a diagram illustrating a method of improving an error of a sensing current in an IPS device according to an embodiment of the present invention.
2 is a diagram illustrating a deviation according to an error of a sensing current in an IPS device according to an embodiment of the present invention.
3 is a flowchart illustrating a method of improving an error of a sensing current of an IPS device according to an embodiment of the present invention.

The above-described objects, features, and advantages will become more apparent through the detailed description described below in detail with reference to the accompanying drawings, and accordingly, those of ordinary skill in the technical field to which the present invention pertains will understand the technical idea of the present invention. You will be able to do it easily. In addition, in describing the present invention, when it is determined that a detailed description of a known technology related to the present invention may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating a method of improving a sensing current error in an IPS device according to an embodiment of the present invention, and FIG. 2 is a diagram illustrating a deviation according to an error in a sensing current in an IPS device according to an embodiment of the present invention. It is a drawing.

In the present invention, when the IPS device supplies a load current to an external device through a battery, when comparing the supplied load current and the sensing current sensed by the control unit, errors and deviations are very large.

In order to reduce errors and deviations between the sensing current and the load current, the constant K and leakage (offset) current values of the IPS devices are identified and adjusted, thereby reducing errors and deviations occurring during current sensing to a minimum.

In the present invention, the sensing current is I _SENSE , and the load current is I _LOAD And leakage (offset) current is I _{SENSE _ OFFSET} , constant K (load current divided by sensing current) is K _ILIS , sensing resistance is R _SENSE , sensing voltage is V _SENSE , leakage (offset) voltage Starts with V _{SENSE _ OFFSET.}

For example, when the battery is 13.5V, the lamp is 55W and 12V, the sensing resistance is 2kΩ, and the sensing current is 10A, errors and deviations that occur when the IPS device senses current can be identified.

[Equation]

I _LOAD = K _ILIS × I _SENSE … … … … … (One)

I _LOAD = K _ILIS × (I _{SENSE -} I _{SENSE _ OFFSET} )… … … … … (2)

V _SENSE = I _SENSE × R _SENSE … … … … … (3)

V _{SENSE _ OFFSET} = I _{SENSE _ OFFSET} × R _SENSE … … … … … (4)

Equation (1) is an equation for calculating the load current, which is calculated by multiplying the constant K and the sensed current.

In addition, Equation (2) is calculated by multiplying the constant K by the sensed current to calculate the load current, and including the leakage current.

In addition, Equation (3) is calculated by multiplying the sensing current and the sensing resistance to calculate the sensing voltage.

In addition, Equation (4) is calculated by multiplying the leakage current and the sensing resistance to calculate the leakage voltage.

Specifically, in FIG. 1, when controlling a load such as a lamp, it can be classified into a first point in time (point 1) and a second point in time (point 2) according to the time of the sensing current.

Here, the first point in time indicates a case in which the sensing current is in a sensing-on state from 0 to t seconds, and the second point in time indicates a case in which the sensing current is in a sensing offset state for t seconds from the sensing on state for t seconds.

Using Equations (1) and (3), I _{LOAD _1} = K _ILIS × I _{SENSE _1} , and I _{LOAD _2} = K _ILIS × I _{SENSE _ 2,} so K _ILIS = (I _{LOAD _1-} I _{LOAD _2} ) / {(V _{SENSE _1} / R _SENSE )-(V _{SENSE _2} / R _SENSE )}.

Here, I _{LOAD _2} is the leakage current value in the no-load state, so I _{LOAD _1 =} K _ILIS /R _SENSE ×(V _{SENSE _1} -V _{SENSE _ OFFSET} ).

In particular, when the IPS device checks the sensing current value at the second point in time, it is possible to check the leakage current value of the actual IPS device under room temperature conditions, not the value of the datasheet of the corresponding IPS device.

Here, assuming that the leakage current value is 50uA (Max. 100uA based on the datasheet), the leakage voltage is the product of the leakage current and the sensing resistance, so 50uA×2kΩ = 0.1V according to Equation (4).

Since the controller calculates the sensing current value using the sensing voltage value, it can be seen that the leakage current value of the corresponding IPS device is 50uA through the actual leakage voltage value of 0.1V.

For example, as shown in Equation (3), the sensing voltage is a value obtained by multiplying the sensing current and the sensing resistance, and as shown in Equation (1), the load current is a value obtained by multiplying the constant K and the sensing current, and if the actual constant K is 6300 , The sensing voltage is 3.27V, and the load current is 12.22A.

Specifically, referring to Equation (3) and Equation (1), V _{SENSE _1} = 2K × (10 / 6300 + 50uA) = 3.27V, and I _{LOAD _1} = K _ILIS / R _SENSE × (V _{SENSE _1} -V _{SENSE _ OFFSET} ), and the Max. Since K _ILIS is 7710, I _{LOAD _1} = 7710/2000 × (3.27-0.1) = 12.22A.

However, if the load current value is calculated based on the sensing current value without considering the leakage current, since the actual leakage current value cannot be known, the Max. 100uA is used.

Specifically, V _{SENSE _1} = 2K × (10 / 6300 + Max 100uA) = 3.37V, I _{LOAD _1 =} K _ILIS / R _SENSE × V _{SENSE _1} , and Max. Since K _ILIS is 7710, I _{LOAD _1 =} 7710/2000 × 3.37 = 12.99A.

In addition, since information on the exact load (current value 10A) is known in the manufacturing process, the constant K can be calculated.

Since V _{SENSE _1} = 2K × (10 / 6300 + 50uA) = 3.27V, I _{LOAD _1} = K _ILIS /R _SENSE ×(V _{SENSE _1} -V _{SENSE _ OFFSET} ), so K _ILIS = 10×2K / (3.27-0.1 ) = 6309, and if you calculate the load current value again based on this, I _{LOAD _1} = 6309/2000 × (3.27-0.1) = 9.99A.

Referring to FIG. 2, when the leakage current value and the constant K value are not reflected, the sensing current is 12.99A based on 10A, and when only the leakage current value is reflected, the sensing current is 12.22A based on 10A. When both the leakage current value and the constant K value are reflected, the sensing current becomes 9.9A based on 10A.

That is, when both the leakage current value and the constant K value are reflected, it can be seen that the deviation of the sensing current is significantly reduced.

3 is a flowchart illustrating a method of improving a sensing current error of an IPS device according to an embodiment of the present invention.

Referring to FIG. 3, the IPS device sets a load current (S10).

Next, the IPS element of each corresponding vehicle component (eg, lamp) is turned on (S20).

Next, the sensing current is measured during a sensing time of 0 to t seconds (S30).

Next, the sensing current is stored in the volatile memory (S40).

Next, the IPS element of each corresponding vehicle component (eg, a lamp) is turned off (S50).

Next, the leakage current is measured for a period of time from t seconds to t seconds (S60).

Next, the leakage current is stored in the nonvolatile memory (S70).

Next, a constant K is calculated using the load current, sensing current, and leakage current (S80).

Next, the constant K is stored in the nonvolatile memory (S90).

As described above, the present technology is a technology capable of controlling a deviation occurring when sensing a load current of a vehicle such as a lamp.

In addition, by controlling the deviation that occurs when sensing the load current of the vehicle, this technology accurately implements the function of detecting disconnection and short circuit of the vehicle such as a lamp, so that the cost competitiveness of a smart junction box equipped with an IPS element and Quality can be secured.

Above, although the present invention has been described by a limited configuration and drawings, the technical idea of the present invention is not limited to these, and by those of ordinary skill in the technical field to which the present invention pertains, the technical idea of the present invention and the following It will be possible to implement various modifications and variations within the equivalent range of the claims to be described.

Claims (5)

The IPS element setting the load current;
Turning on the IPS element of each corresponding vehicle;
measuring a sensing current of a load or wiring during a sensing time of t seconds;
Turning off the IPS device of the vehicle;
Measuring a leakage current of a load or wiring for a time period after t seconds; And
Calculating a constant K representing a ratio of a load current and a sensing current using the load current, the sensing current, and the leakage current;
Including,
The value of the load current used in the process of calculating the constant K is obtained from an accurate load current value already stored in a memory. The method according to claim 1,
Between measuring the sensing current during the sensing time of t seconds and turning off the IPS element of the vehicle,
And storing the sensing current in a volatile memory. The method according to claim 1,
Between the step of measuring a leakage current for a time after t seconds and calculating a constant K using the load current, the sensing current, and the leakage current,
And storing the leakage current in a nonvolatile memory. The method according to claim 1,
After the step of calculating the constant K using the load current, the sensing current and the leakage current,
And storing the constant K in a nonvolatile memory. The method according to claim 1,
The constant K is a sensing current error improvement method of an IPS device, characterized in that a value obtained by dividing the load current by the sensing current.

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