Patent Description:
The present invention relates to relay abnormality diagnosis system and method, and more particularly, to relay abnormality diagnosis system and method capable of diagnosing an abnormality of a relay by directly connecting a diagnosis resistor to a current measurement unit and by using a current input to the current measurement unit from the diagnosis resistor and a current flowing on an electric circuit measured by the current measurement unit, in the relay abnormality diagnosis system that diagnoses the abnormality of the relay using the diagnosis resistor.

A relay is a switching device that operates when an input reaches a certain value to open or close another circuit. The relay has advantages that the relay may be interlocked with an independent circuit and turn on or off a large current circuit by an operation of a circuit configured of a low voltage system such as <NUM> V. In addition, since a coil portion and a contact portion in the relay are insulated and separated, there is an advantage that the relay may be electrically insulated from an external device. Because of such advantages, the relay is being utilized as a switching device in various fields where on/off switching is required.

In general, when an abnormal current flows on an electric circuit, the relay performs an on/off operation based on a control signal, thereby preventing a load from being damaged from the abnormal current.

However, when the relay is not able to be operated due to occurrence of an abnormality such as a welding of the relay, in a case where an abnormal current such as a high current flows on the electric circuit, the abnormal current may not be blocked and thus the load may be greatly damaged.

In order to solve this problem, in the related art, it has been prevented in advance that such a problem occurs by monitoring and diagnosing whether an abnormality occurs in a relay using a relay abnormality diagnosis system.

On the other hand, the relay abnormality diagnosis system in the related art uses a method in which a resistor and a switch are connected in series between a load terminal (DC link) and a negative terminal of a power source such as a battery, and at a time of a relay diagnosis, a current flowing on the resistor is measured after a conduction state of the switch is changed to an ON state.

However, when using such a relay abnormality diagnosis system of the related art, since a wire (DC link wire) for connecting the relay abnormality diagnosis system and a relay side, a wire (PACK minus wire) for connection to a negative terminal side of the battery, a MOSFET switch and a large number of resistors are required, there are problems that a volume of the system increases and a cost increases.

Therefore, the present inventor has developed relay abnormality diagnosis system and method capable of reducing a use of a large number of resistors and wires, by directly connecting a diagnosis resistor to a current measurement unit and by using a current input to the current measurement unit from the diagnosis resistor and a current flowing on an electric circuit measured by the current measurement unit, to diagnose an abnormality of a relay, in the relay abnormality diagnosis system that diagnoses the abnormality of the relay using the diagnosis resistor.

Prior art is disclosed in <CIT>, <CIT>, <CIT>, <NPL> and <CIT>.

The present invention has been made to solve the above-described problems, and it is an object of the present invention to provide a relay abnormality diagnosis system and a method capable of reducing a use of a large number of resistors and wires and to precisely indicate the type of failure occurring in the relay unit. This object is accomplished by directly connecting a diagnosis resistor that is positioned on one printed circuit board (PCB) to a current measurement unit through a circuit pattern and diagnosing an abnormality of a relay unit based on a current input to the current measurement unit from the diagnosis resistor unit and a current flowing on an electric circuit measured by the current measurement unit, in the relay abnormality diagnosis system that diagnoses the abnormality of the relay using the diagnosis resistor.

A relay abnormality diagnosis system according to the present invention is defined in claim <NUM>.

In an embodiment, the diagnosis resistor unit may include one or more resistors, and a switch configured to change a conduction state between the relay and the current measurement circuit.

In an embodiment, to diagnose the abnormality of the relay, the control circuit may be configured to output a control signal for controlling the conduction state of the switch.

In an embodiment, the current measurement unit may be configured to measure the current flowing on the electric circuit by using a shunt resistor positioned on the electric circuit.

In an embodiment, the relay may be positioned between a positive terminal of a battery that is positioned on the electric circuit and a load, and the shunt resistor may be positioned between a negative terminal of the battery and the load.

In an embodiment, the current measurement circuit, the diagnosis resistor unit, and the control circuit may be positioned on a printed circuit board (PCB), and may be interconnected through a circuit pattern.

A relay abnormality diagnosis method according to the present invention is defined in claim <NUM>.

In an embodiment, the diagnosis resistor unit may include one or more resistors, and a switch configured to change a conduction state between the relay and the current measurement circuit, and switchably controlling the connection between the relay and the current measurement circuit may include controlling the switch.

In an embodiment, diagnosing the abnormality of the relay may include outputting, by the control circuit, a control signal for controlling the conduction state of the switch.

In an embodiment, measuring the current may include measuring the current flowing on the electric circuit using a shunt resistor positioned on the electric circuit.

In an embodiment, switchably controlling the connection between the relay and the current measurement circuit may be performed on a relay that may be positioned between a positive terminal of a battery that is positioned on the electric circuit and a load, and measuring the current flowing on the electric circuit may be performed using a shunt resistor that may be positioned between a negative terminal of the battery and the load.

In an embodiment, the current measurement circuit, the diagnosis resistor unit, and the control circuit may be positioned on one printed circuit board (PCB), and may be interconnected through a circuit pattern.

The present invention directly connects a diagnosis resistor unit and a current measurement unit with each other and diagnoses an abnormality of a relay based on a current input to the current measurement unit from the diagnosis resistor unit and a current flowing on an electric circuit measured by the current measurement unit. Therefore, there is an advantage that it is possible to prevent occurrence of a secondary accident due to overvoltage or overcurrent by quickly determining whether or not the relay is faulty.

In addition, the present invention directly connects the diagnosis resistor unit and the current measurement unit that are positioned on one printed circuit board (PCB) with each other through a circuit pattern. Therefore, there is an advantage that it is not necessary to connect the diagnosis resistor unit and a negative terminal of a battery with each other by using a wire, thereby reducing volume and cost of a system.

In addition, in the present invention, since the current flowing through the diagnosis resistor unit is directly input to the current measurement unit, it is not necessary to adjust a value of the current flowing through the diagnosis resistor unit, thereby reducing the number of resistors used in the diagnosis resistor unit.

Hereinafter, a preferred embodiment of the present invention will be described in order to facilitate understanding of the present invention. However, the following embodiment is provided only for the purpose of easier understanding of the present invention, and the present invention is not limited by the embodiment.

<FIG> is a diagram schematically illustrating a relay abnormality diagnosis system <NUM> of the related art.

Referring to <FIG>, the relay abnormality diagnosis system <NUM> of the related art includes a battery <NUM>, a relay <NUM>, a shunt resistor <NUM>, an ASIC <NUM>, a diagnosis resistor <NUM>, an MCU <NUM>, and connectors <NUM>-<NUM> and <NUM>-<NUM>.

The ASIC <NUM> measures a current on an electric circuit including the battery <NUM> and the relay <NUM>, as a current measurement element. At this time, the shunt resistor <NUM> may be positioned on the electric circuit, and the ASIC <NUM> measures a current flowing on the electric circuit by measuring a current flowing through the shunt resistor <NUM>.

The diagnosis resistor <NUM> is used to diagnose an abnormality of the relay <NUM>. For example, one side of the diagnosis resistor <NUM> is connected to the relay <NUM> and another side of the diagnosis resistor <NUM> is connected to the shunt resistor <NUM>. Therefore, the diagnosis resistor <NUM> is connected to the battery <NUM> in parallel.

The MCU <NUM> controls each component included in the relay abnormality diagnosis system <NUM> of the related art and diagnoses the abnormality of the relay <NUM> based on the current measured by the ASIC <NUM>.

When the abnormality of the relay <NUM> is to be diagnosed by using the above-described relay abnormality diagnosis system <NUM> of the related art, since the current flowing through the diagnosis resistor <NUM> is required to be measured, it was necessary to additionally include a current measurement device capable of measuring the current flowing through the diagnosis resistor <NUM>.

When the diagnosis resistor <NUM> is connected to the shunt resistor <NUM> and the current is measured using the shunt resistor <NUM> and the ASIC <NUM>, since a negative electrode side connector <NUM>-<NUM> and an electric circuit are required to be connected with each other by using a wire in order to provide the current flowing through the diagnosis resistor <NUM> to the shunt resistor <NUM>, an additional wire is required to be installed.

In addition, when the current is measured using the shunt resistor <NUM> and the ASIC <NUM>, since it is necessary to adjust a magnitude of the current flowing through the shunt resistor <NUM>, the diagnosis resistor <NUM> is required to use a plurality of resistors by connecting the plurality of resistors with each other in series and in parallel.

That is, the relay abnormality diagnosis system <NUM> of the related art has a problem that a volume of the system is increased and a cost of the system is increased due to additional current measurement element, resistor and wire. Hereinafter, a relay abnormality diagnosis system <NUM> according to an embodiment of the present invention capable of solving the problems of the relay abnormality diagnosis system <NUM> of the related art will be described with reference to <FIG> and <FIG>.

<FIG> is a diagram schematically illustrating a relay abnormality diagnosis system <NUM> according to an embodiment of the present invention.

Referring to <FIG>, the relay abnormality diagnosis system <NUM> according to an embodiment of the present invention includes a relay unit <NUM>, a current measurement unit <NUM>, a shunt resistor <NUM>, a diagnosis resistor unit <NUM>, connectors <NUM>-<NUM> and <NUM>-<NUM>, and a control unit <NUM>.

The relay abnormality diagnosis system <NUM> illustrated in <FIG> is a system according to an embodiment, and components thereof are not limited to the embodiment illustrated in <FIG>, and can be added, changed or deleted as necessary. For example, the current measurement unit <NUM> and the control unit <NUM>, which will be described later, may include a control circuit, such as a micro control unit (MCU). The MCU may simultaneously perform both a current measurement function and a control function.

First, the relay unit <NUM> may be a relay positioned on the electric circuit including the battery <NUM> and a load <NUM>', and may provide electric power output from the battery <NUM> to the load <NUM>' or perform short-circuit by controlling a conduction state on the electric circuit.

Here, although the relay unit <NUM> of <FIG> is illustrated as a relay capable of controlling the conduction state according to an input value, the present invention is not limited thereto and any component that is positioned on the electric circuit and is capable of controlling the conduction state on the electric circuit may be applied to the present invention. For example, the relay unit <NUM> may be a contactor, a transistor, and a thyristor.

Here, the conduction state may refer to an on state in which the electric circuit is connected without breaking to form a closed circuit and thus a current may flow on the electric circuit and an off state in which one surface side of the electric circuit is opened or shorted to form an open circuit and thus a current may not flow on the electric circuit.

In an embodiment, the relay unit <NUM> may be used in a form in which a plurality of relays are connected with each other based on a magnitude of the current flowing on the electric circuit and a magnitude of a voltage applied to the load.

In an embodiment, the relay unit <NUM> may be positioned between a positive terminal of the battery <NUM> and the load <NUM>' positioned on the electric circuit.

The current measurement unit <NUM> may be a current measurement circuit, such as the MCU described above, that is capable of measuring the current flowing on the electric circuit including the battery <NUM> and the load <NUM>'. For example, the shunt resistor <NUM> may be positioned on the electric circuit including the battery <NUM> and the load <NUM>', and the current measurement unit <NUM> may be a current measurement circuit capable of measuring the current flowing on the electric circuit by measuring the current flowing on the shunt resistor <NUM> using the shunt resistor <NUM>.

For example, the current measurement unit <NUM> may include an operational amplifier. The operational amplifier may amplify a voltage value of the battery <NUM> applied to the shunt resistor <NUM> in proportion to a predetermined gain value and the current measurement unit <NUM> may measure the current flowing on the electric circuit including the battery <NUM> and the load <NUM>' by calculating the current using the amplified voltage value, a resistance value of the shunt resistor <NUM>.

In an embodiment, the shunt resistor <NUM> may be installed on a bus bar for connecting the battery <NUM> and the load with each other as illustrated in <FIG> and may be positioned between a negative terminal of the battery <NUM> and the load <NUM>'.

The diagnosis resistor unit <NUM> may be used to diagnose the abnormality of the relay unit <NUM> and connect or disconnect the relay unit <NUM> to or from the current measurement unit <NUM>. To this end, the diagnosis resistor unit <NUM> may include one or more diagnosis resistors 140a and a switch unit 140b.

One side of the one or more diagnosis resistors 140a may be connected to the relay unit <NUM> through a positive electrode connector <NUM>-<NUM> and the other side of the one or more diagnosis resistors 140a may be connected to the switch unit 140b that will be described later.

In addition, the one or more diagnosis resistors 140a may be connected to the battery <NUM> in parallel and may have a predetermined resistance value to output a current of a predetermined magnitude by receiving a voltage from the battery <NUM>. For example, the diagnosis resistors 140a may be in a form in which one or more resistors are connected with each other in series or in parallel.

The switch unit 140b may change the conduction state between the relay unit <NUM> and the current measurement unit <NUM>. For example, the switch unit 140b may be a metal oxide semiconductor field effect transistor (MOSFET) as illustrated in <FIG>, and when a control signal output from the control unit <NUM> that will be described later is input to a gate terminal, the switch unit 140b becomes an on state, and thus the relay unit <NUM> and the current measurement unit <NUM> may be connected with each other.

One side of the switch unit 140b may be connected to the one or more diagnosis resistors 140a and the other side of the switch unit 140b may be directly connected to the current measurement unit <NUM> rather than being connected to the shunt resistor <NUM> through the negative electrode connector <NUM>-<NUM>.

In an embodiment, the current measurement unit <NUM>, the diagnosis resistor unit <NUM>, and the control unit <NUM> that will be described later may be positioned on one printed circuit board (PCB) and may be interconnected through a circuit pattern. For example, the switch unit 140b may be connected to the current measurement unit <NUM> in the circuit pattern on the PCB. Therefore, since the relay abnormality diagnosis system <NUM> according to an embodiment of the present invention does not connect the diagnosis resistor unit <NUM> and the shunt resistor <NUM> with each other through a wire, and simply connects the current measurement unit and the diagnosis resistor unit <NUM> with each other through the circuit pattern, it is not necessary to use a wire. Thus, there is an advantage that a volume and a manufacturing cost of the system may be reduced.

The control unit <NUM> is configured to connect the relay unit <NUM> and the current measurement unit <NUM> with each other by controlling the diagnosis resistor unit <NUM>. For example, when it is desired to diagnose the abnormality of the relay unit <NUM>, the control unit <NUM> may output a control signal for controlling the conduction state of the switch unit 140b, and the switch unit 140b may connect the relay unit <NUM> and the current measurement unit <NUM> with each other by changing the conduction state to the on state according to the control signal.

The control unit <NUM> is configured to diagnose the abnormality of the relay unit <NUM> based on the current input to the current measurement unit <NUM> from the diagnosis resistor unit <NUM> and the current flowing on the electric circuit measured by the current measurement unit <NUM>.

When the control unit <NUM> intends to diagnose the abnormality of the relay unit <NUM>, the control unit <NUM> calculates a difference value between the current flowing on the electric circuit measured by the current measurement unit <NUM> and the current input to the current measurement unit <NUM> from the diagnosis resistor unit <NUM>, and diagnoses the abnormality of the relay unit <NUM> based on the calculated difference value between the currents. Hereinafter, the present invention will be described in more detail with reference to <FIG>.

<FIG> is a diagram schematically illustrating a flow of the current output from the battery <NUM> in the relay abnormality diagnosis system <NUM> according to an embodiment of the present invention.

Referring to <FIG>, the current I1 output from the battery <NUM> is divided into a current I2 flowing toward the load <NUM>' and a current I3 flowing toward a positive electrode connector <NUM>-<NUM> while passing through the relay unit <NUM>. At this time, the current I1 output from the battery <NUM> may be divided inversely proportional to a resistance value of the load <NUM>' and a resistance value of the diagnosis resistor 140a. Thereafter, the current I2 flowing toward the load <NUM>' is divided into a current I4 flowing toward the negative terminal of the battery <NUM> and a current I5 flowing through the shunt resistor <NUM> while passing through the shunt resistor <NUM>, and the current measurement unit <NUM> measures the current I5 flowing through the shunt resistor <NUM>. At this time, since the current measurement unit <NUM> receives the current I3 flowing from the diagnosis resistor unit <NUM> to the positive electrode connector <NUM>-<NUM>, the current measurement unit <NUM> actually measures a current value obtained by summing the current I3 flowing toward the positive electrode connector <NUM>-<NUM> and the current I5 flowing through the shunt resistor <NUM>.

The control unit <NUM> calculates the difference value I5 between the current I3 flowing on the electric circuit from the currents (I3 + <NUM>) measured by the current measurement unit <NUM> and diagnoses the abnormality of the relay unit <NUM> based on the calculated difference value I5 between the currents.

In an embodiment, the relay abnormality diagnosis system <NUM> according to an embodiment of the present invention may experimentally measure the current value flowing through the diagnosis resistor 140a under one or more conditions among the resistance value of the diagnosis resistance value 140a, a type of the relay unit <NUM>, a type of failure occurring in the relay unit <NUM>, and the voltage value and the current value of the battery <NUM>, and may include a storage unit (not illustrated) capable of storing the measured current value in a data table.

The control unit <NUM> is configured to calculate the difference value between the current flowing on the electric circuit and the current input to the current measurement unit <NUM> from the diagnosis resistor unit <NUM>, and may diagnose the abnormality of the relay unit <NUM> by comparing the calculated current with the current value stored in the storage unit.

The storage unit (not illustrated) is capable of storing the current value measured by the current measurement unit <NUM>. The control unit <NUM> is configured to analyze tendency and a pattern of the stored current value to detect an abnormal symptom, and when the abnormal symptom is detected, the control unit <NUM> diagnoses that the abnormality has occurred in the relay unit <NUM>. Hereinafter, with reference to <FIG>, a method of diagnosing the abnormality of the relay unit using the relay unit abnormality diagnosis system <NUM> according to an embodiment of the present invention will be described.

<FIG> is a flowchart illustrating a series of processes of diagnosing the anomaly of the relay using the relay abnormality diagnosis system <NUM> according to an embodiment of the present invention.

Referring to <FIG>, first, a relay unit abnormality diagnosis request is received (S110).

Here, the relay unit abnormality diagnosis request may be a signal input from an outside so as to diagnose the abnormality of the relay unit. However, the present invention is not limited thereto, and the relay abnormality diagnosis system may repeatedly perform the relay unit abnormality diagnosis operation at a predetermined time interval even though an additional abnormality diagnosis request signal and instruction are not input.

In step S <NUM>, when the relay unit abnormality diagnosis request is received, the control unit controls the diagnosis resistor unit to connect the relay unit and the current measurement unit with each other (S120) and measures the current using the shunt resistor in the current measurement unit (S130).

Thereafter, the control unit calculates the difference value between the current flowing on the electric circuit and the current input to the current measurement unit from the diagnosis resistor unit based on the current measured in steps S120 and S130 (S140), and diagnoses the abnormality of the relay unit based on the calculated difference value between the currents (S <NUM>).

When the abnormality of the relay unit is not diagnosed in step S <NUM>, the process may return to step S <NUM> and steps S <NUM> to S <NUM> may be repeatedly performed.

The above-described relay abnormality diagnosis method has been described with reference to the flowcharts illustrated in the drawings. While the above-described method has been illustrated and described as a series of blocks for purposes of simplicity, the present invention is not limited to the sequence of the above-described blocks, some blocks may occur in different sequences or simultaneously with other blocks as illustrated and described in the present specification, and various other branches, flow paths, and sequences of blocks that achieve the same or similar results may be implemented. In addition, not all illustrated blocks may be required for the implementation of the method described in the present specification.

Claim 1:
A relay abnormality diagnosis system (<NUM>) comprising:
a relay (<NUM>) positioned on an electric circuit;
a current measurement circuit (<NUM>) configured to measure a current flowing on the electric circuit;
a diagnosis resistor unit (<NUM>) configured to switchably connect or disconnect the relay (<NUM>) and the current measurement circuit (<NUM>);
a storage unit capable of storing the measured current value in a data table; and
a control circuit (<NUM>) configured to control the connection between the relay (<NUM>) and the current measurement circuit (<NUM>) via the diagnosis resistor unit (<NUM>),
characterized in that the control circuit (<NUM>) is configured to diagnose an abnormality of the relay (<NUM>) by:
calculating a difference value between the measured current flowing on the electric circuit and a current input to the current measurement circuit (<NUM>) from the diagnosis resistor unit (<NUM>); and
analyzing a tendency and a pattern of the stored current value to detect an abnormal symptom.