JP2016086549A - Detection system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detection system configured to detect lock and unlock states without requiring new wiring, while ensuring regenerative current flow during rotation of a motor with no trouble.SOLUTION: In a system for switching lock and unlock of a lock 20 by supplying a current from a motor control switch 10 constituting an H bridge circuit to a motor M1, a switch SW6 where diodes D3 and D4 are connected in parallel in opposite directions from each other is arranged in series with the motor M1, and connection state of the switch SW6 is switched depending on the fact whether the lock 20 is in locked state or unlocked state. Voltage drop values of the diodes D3 and D4 during energization are differentiated. Determination is made whether the lock 20 is in locked state or unlocked state, by supplying a current not causing rotary driving of the motor M1 from a switch 11, and detecting the potential of an energization line L1 at that time.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a detection system.

  2. Description of the Related Art Conventionally, there has been proposed an apparatus that detects whether a locking part (locking part) such as a door is in a locked state or an unlocked state. For example, Patent Literature 1 below discloses a locking / unlocking detection device that does not require a new wiring for detecting locking / unlocking.

JP 2010-7350 A

  FIG. 5 shows an outline of the apparatus disclosed in Patent Document 1. 5 mainly includes an electronic control unit 1 ′ (ECU) and a lock mechanism 2 ′. The ECU 1 ′ includes a motor control switch 10, voltage detection units 11 ′ and 12 ′, and an MPU 13 ′, and a lock mechanism 2 ′ includes A DC motor M1 (motor), a switch SW5, and a lock unit 20 ′ are provided.

  The motor control switch 10 has a well-known H-bridge circuit structure including four switches SW1 to SW4. The switch SW1 and SW4 are turned on and the switches SW2 and SW3 are turned off. A current is supplied, and an upward direct current is supplied to the motor M1 in a state where the switches SW2 and SW3 are on and the switches SW1 and SW4 are off (here, V1 and V2 in the figure are positive potentials). .

  The rotor of the motor M1 is mechanically connected to the lock unit 20 ′, and the lock unit 20 ′ is locked by rotation of a predetermined angle in a direction of the rotor (referred to as a positive direction), and vice versa. The lock portion 20 ′ is unlocked by rotation of the direction by a predetermined angle. In the following, for example, when a downward direct current is supplied, the rotor rotates in the forward direction (the lock portion 20 'is locked), and when a downward direct current is supplied, the rotor rotates in the reverse direction (locked). Part 20 'is unlocked).

  In the configuration of FIG. 5, a switch SW5 is arranged in series with the motor M1. The switch SW5 has a structure in which diodes D1 and D2 are connected in parallel in opposite directions as shown. A contact is joined to a predetermined gear of the lock portion 20 ′ (not shown). When the lock portion 20 ′ is in a locked state, the terminal A ′ is in a connected state, and when the lock portion 20 ′ is in an unlocked state, a terminal is connected. The contact moves with the gear so that B ′ is in the connected state (detailed description of the mechanism is omitted).

  Therefore, when the switches SW1 and SW4 are turned on by the motor control switch 10 when the lock portion 20 ′ is in the unlocked state, the diode D2 becomes conductive and current flows downward in the figure to the motor M1, so that the rotor is in the positive direction. And the lock portion 20 'shifts to the locked state. When the lock portion 20 'is locked, the switch A5 of the switch SW5 is switched to the connected state.

  On the contrary, when the switches SW2 and SW3 are turned on by the motor control switch 10 when the lock portion 20 ′ is in the locked state, the diode D1 becomes conductive and current flows through the motor M1 upward in the drawing, so that the rotor moves in the reverse direction. , The lock portion 20 'shifts to the unlocked state, and the switch SW5 switches the terminal B' to the connected state. As described above, in the configuration of FIG. 5, either one of the diodes D1 and D2 is in a conductive state in the switch SW5.

  In Document 1, under such a configuration, it is detected whether the lock portion 20 ′ is locked or unlocked. Specifically, first, a current is supplied from the motor control switch 10 only for a minute period during a period when the unlocking operation is not performed. The voltages (potentials) of the energization lines L1 and L2 are detected by the voltage detectors 11 'and 12'. When it is detected that the electric potential of the energization line L1 is higher, it can be determined that the diode D2 is in a conductive state, and thus the lock portion 20 'is in an unlocked state. On the contrary, if it is detected that the potential of the energization line L2 is higher, the diode D1 is in the conductive state, and therefore it can be determined that the lock portion 20 'is in the locked state.

  In the configuration of FIG. 5, as described above, only D2 of the diodes D1 and D2 is in a conducting state during the locking operation, and only D1 of the diodes D1 and D2 is in a conducting state during the unlocking operation. Therefore, only a downward current flows during the locking operation, and only an upward current flows during the unlocking operation.

  In general, when a DC motor is rotated at a certain angle, a current is supplied to the motor for a certain period to start rotation of the rotor in a stationary state, and the current supply is stopped during the subsequent period, and the kinetic energy of the rotor is determined by the principle of electromagnetic induction. Is braked and finally stopped by converting it into electrical energy. This electric energy becomes a so-called regenerative current and flows in a direction opposite to the current supplied to rotate the rotor.

  Since this phenomenon occurs in FIG. 5 as well, an upward regenerative current tends to flow during a period near the end of the locking operation period, for example, and a downward regenerative current illustrated during the period near the end of the unlocking operation period, for example. Tries to flow. However, as described above, the switch SW5 operates so that only a downward current flows during the locking operation period, and only an upward current flows during the unlocking operation period. Therefore, in the configuration of FIG. 5, the regenerative current is inhibited, and the back electromotive force generated so as to flow the regenerative current cannot be processed. This leads to destruction of peripheral parts including the motor M1. Development of a lock / unlock detection system that can avoid this phenomenon is required.

  Therefore, in view of the above, the problem to be solved by the present invention is a detection system configured to detect a locked state and an unlocked state without requiring a new wiring, and to allow a regenerative current to flow without trouble during motor rotation. Is to provide.

  In order to achieve the above object, a detection system according to the present invention is driven by a DC motor at a position in series with the DC motor in an H-bridge circuit connected to supply electric power in both forward and reverse directions to the DC motor. The DC motor is connected in such a way that the connection state is switched depending on whether the lock portion is locked or unlocked, and the DC motor receives current in both forward and reverse directions regardless of whether the lock portion is locked or unlocked. An element part that can flow and has a voltage drop value that differs depending on the locking and unlocking of the lock part, and a potential at a point where the voltage drop value of the element part is reflected in the H-bridge circuit And a detection unit for detecting. According to the present invention, since the element portion is configured to allow current to flow in both forward and reverse directions with respect to the DC motor, the regenerative current can be passed without any trouble when the motor rotates. Since only potential detection is performed, locking / unlocking detection can be performed without new wiring. Therefore, it is possible to realize a detection system configured such that detection of the locked and unlocked state can be performed without the need for new wiring, and the regenerative current flows when the motor rotates.

  The element section includes a first diode section in which at least one diode is connected in series with the same energization direction, and a second diode section in which at least one diode is connected in series with the same energization direction. Are connected in parallel with the energization direction being opposite to each other, and the voltage effect value during energization differs between the first diode portion and the second diode portion, and the lock portion is in the locked state or unlocked state And a connection control unit that switches a connection state of the diode unit in the H bridge circuit. According to the present invention, by using a configuration in which diodes that are opposite to each other are connected in parallel, the locked and unlocked state can be detected without the need for new wiring, and the regenerative current during motor rotation flows without trouble. A detection system configured as described above can be realized.

  The connection control unit may be configured such that when the lock unit is locked, the first diode unit is energized when current is supplied from the current supply unit, and when the lock unit is unlocked, the current The diode unit may be connected in the H-bridge circuit so that the second diode unit is energized when current is supplied from the supply unit. According to the present invention, the configuration in which the diodes connected in reverse to each other are connected in parallel can switch the connection state according to whether it is in the locked state or the unlocked state, so that the detection of the locked and unlocked state can be performed without the need for new wiring. In addition, it is possible to realize a detection system configured such that a regenerative current flows when the motor rotates.

  In addition, even if a power supply unit is provided to supply current to the element unit and the DC motor so that the DC motor does not rotate in a state where power is not supplied from the H bridge circuit to the DC motor. Good. According to the present invention, since the DC motor is supplied with a current that does not rotate when the H bridge circuit does not supply power to the DC motor, the load on the motor when detecting locking / unlocking is reduced. it can.

  The detection unit may include an abnormality determination unit that determines whether or not there is an abnormality in the current path according to the detected potential. According to the present invention, it is possible to realize a system capable of detecting not only locking / unlocking but also path abnormality.

The block diagram in one Example of the detection system of this invention. The flowchart which shows the 1st example of the process sequence in this invention. The flowchart which shows the 2nd example of the process sequence in this invention. The flowchart which shows the 3rd example of the process sequence in this invention. The figure which shows the structural example of the detection system in a prior art.

  Embodiments of the present invention will be described below with reference to the drawings. First, FIG. 1 is a schematic diagram of a device configuration of a detection system (hereinafter, system) according to an embodiment of the present invention. The system shown in FIG. 1 includes an electronic control unit 1 (ECU) and a lock mechanism 2. The ECU 1 includes a motor control switch 10 (switch), a lock / unlock detection switch 11 (switch), a voltage detection unit 12, and an MPU 13. The lock mechanism 2 includes a DC motor M1 (motor), a lock unit 20, and a switch SW6. .

  The switch 10 has a well-known H-bridge circuit configuration as described above, and supplies a direct current for driving the motor M1 in both forward and reverse directions. Hereinafter, the voltages V1 and V2 in FIG. 1 are assumed to be positive DC voltages. A downward current is supplied to the motor M1 with the switches SW1 and SW4 turned on and the switches SW2 and SW3 turned off. Further, an upward current is supplied to the motor M1 with the switches SW1 and SW4 off and the switches SW2 and SW3 on.

  The switch 11 is a part that detects whether the lock unit 20 is in a locked state or an unlocked state. Hereinafter, the voltage V3 in FIG. 1 is a positive DC voltage. When all of the four switches SW1, SW2, SW3, and SW4 are turned off in the switch 10, and the switches SW7 and SW8 are both turned on by the switch 11, a direct current is supplied to the motor M1 and the switch SW6. The resistance values of the electric resistances R1 and R2 are increased so that the current value at that time does not rotate the rotor of the motor M1 (the torque generated by the current supply does not exceed the static friction force generated in the rotor). Keep it.

  In this way, when the current is supplied from the switch 11, the voltage detector 12 detects the voltage (potential) of the energization line L1. Based on this voltage detection value, it can be determined whether the lock unit 20 is in the locked state or the unlocked state (described later). In the period when the voltage is not detected by the voltage detector 12, both the switches SW7 and SW8 in the switch 11 may be turned off.

  The MPU 13 includes the same configuration as that of an ordinary computer, that is, a CPU that performs various information processing, a RAM as a work area of the CPU, a nonvolatile storage unit that stores various data and programs, and the like. The MPU 13 transmits signals S1, S2, S3, S4, S9, and S10 for commanding on / off switching to the switches SW1, SW2, SW3, SW4, SW7, and SW8. Further, the MPU 13 receives a signal S11 indicating a voltage value detected from the voltage detection unit 12.

  Next, the motor M1 is a direct current motor, and rotates in both forward and reverse directions (rotor) according to the direction of the supplied direct current. In the following, the downward current supplied to the motor M1 is referred to as a positive current, and the upward current is referred to as a reverse current. When the positive current is supplied, the rotation of the motor M1 (rotor) is forward rotation and the reverse current is The rotation of the motor M1 (rotor thereof) when supplied is referred to as reverse rotation.

  The lock unit 20 is a locking unit that is locked and unlocked by a conventional rotational movement attached to a door, for example, and is switched by the motor M1 between a locked state and an unlocked state. In the present invention, the locking portion of the lock portion 20 is general, and there is no limitation on what is locked. The drive of the lock unit 20 by the motor M1 may have an arbitrary structure. For example, rotation information of the motor M1 may be transmitted by an electric signal S5 as shown in FIG. A mechanism in which each of the 20 rotating parts is mechanically connected and the rotational movement of the motor M1 is transmitted and unlocked may be used. In the following, it is assumed that the lock unit 20 is locked when the motor M1 rotates forward and unlocked when the motor M1 rotates reversely.

  The switch SW6 is a switch that is arranged in a portion in series with the motor M1 in the H-bridge circuit, and switches the connection state depending on whether the lock unit 20 is in the locked state or the unlocked state. As shown in the figure, the switch SW6 has a structure in which diodes D3 and D4 are connected in parallel so that the energization directions are opposite to each other. The diodes D3 and D4 have different voltage drop values in the energized state.

  The switch SW6 is switched between two states: a state in which the terminals A and D are connected to the H bridge circuit, and a state in which the terminals B and C are connected to the H bridge circuit. Switching of the switch SW6 depending on the locking / unlocking state of the lock unit 20 may be an arbitrary structure, for example, as illustrated in FIG. 1, the lock / unlock information of the lock unit 20 may be transmitted and switched by an electrical signal S6. The lock unit 20 and the switch SW6 may be mechanically connected, and the connection state of the switch SW6 may be mechanically switched according to the lock / unlock state of the lock unit 20.

  In the system of FIG. 1 having the above configuration, the processes of FIGS. 2 to 4 are executed. Among these, FIG. 3 is a processing procedure for switching the lock unit 20 from the unlocked state to the locked state. 3, the lock unit 20 is in an unlocked state, and the switch SW6 has points A and D connected to the H bridge circuit. The switches SW1, SW2, SW3, and SW4 are all off.

  In the processing procedure of FIG. 3, first, in S100, the MPU 13 receives the locking command from the user, for example, and switches on the switches SW1 and SW4. As a result, a positive current flows through the motor M1 as described above, and the motor rotates forward (S110). When the motor M1 rotates forward, the lock unit 20 is switched from the unlocked state to the locked state as described above (S120). When the lock unit 20 is locked, the switch SW6 is connected to the H bridge circuit at points B and C (S130). When the above processing is completed, the MPU 13 turns off the switches SW1 and SW4 (S140). The lock unit 20 is switched to the locked state by the processing of FIG. 3 as described above, and the switch SW6 is switched to a state where the points B and C are connected.

  FIG. 4 is a processing procedure for switching the lock unit 20 from the locked state to the unlocked state. At the start of the process of FIG. 4, the lock unit 20 is in a locked state, and the switch SW6 has points B and C connected to the H bridge circuit. The switches SW1, SW2, SW3, and SW4 are all off.

  In the processing procedure of FIG. 4, first, in S200, the MPU 13 receives, for example, an unlocking command from the user, and switches on the switches SW2 and SW3. As a result, a reverse current flows through the motor M1 as described above, and the motor rotates in the reverse direction (S210). When the motor M1 rotates in the reverse direction, the lock unit 20 is switched from the locked state to the unlocked state as described above (S220). When the lock unit 20 is unlocked, the switch SW6 is connected to the H bridge circuit at points A and D (S230). When the above processing is completed, the MPU 13 turns off the switches SW2 and SW3 (S240). 4 is switched to the unlocked state, and the switch SW6 is switched to a state where the points A and D are connected.

  Next, FIG. 2 shows a processing procedure for detecting whether the lock unit 20 is in a locked state or an unlocked state. The processing procedure of FIG. 2 may be programmed in advance and stored in, for example, the MPU 13 and called by the MPU 13 and executed. 2 includes not only determination of the locked state / unlocked state but also determination of path abnormality. The time point at which the process of FIG. 2 is executed may be a period when the locking operation or unlocking operation of the lock unit 20 is not performed, that is, when the switches SW1, SW2, SW3, and SW4 are all off in the switch 10. The locking and unlocking of the unit 20 may be constantly monitored.

  In the processing procedure of FIG. 2, the MPU 13 first turns on the switches SW7 and SW8 in S10. As a result, a positive current flows through the motor M1 (the voltage V3 is positive). Since the resistance values of the resistors R1 and R2 are set as described above, the motor M1 does not rotate.

At this time, if the lock unit 20 is in the locked state, the point B and the point C are connected by the switch SW6 by the process of FIG. 3, so that the diode D4 becomes conductive. In that case, the voltage drop value at the switch SW6 is the voltage drop value VfD4 of the diode D4. And the electric potential of the energization line L1 becomes the next Vc by simple calculation.
Vc = (V3-VfD4) * (R2 / (R1 + R2)) + VfD4

Also, if the lock unit 20 is in the unlocked state, the point D and the point D are connected by the switch SW6 by the process of FIG. 4, so that the diode D3 becomes conductive. In that case, the voltage drop value at the switch SW6 is the voltage drop value VfD3 of the diode D3. And the electric potential of the energization line L1 becomes the following Vo by simple calculation.
Vo = (V3−VfD3) * (R2 / (R1 + R2)) + VfD3

  As described above, VfD3 and VfD4 are different numerical values. Therefore, Vc and Vo are also different numerical values. The MPU 13 determines whether there is a path abnormality in S20. Specifically, the voltage detection unit 12 detects the voltage of the energization line L1, and if the value is different from both Vc and Vo, it is determined that the path is abnormal. If the path is abnormal (S20: YES), the process proceeds to S60. If the path is not abnormal (S20: NO), the process proceeds to S30.

  After proceeding to S30, the MPU 13 determines whether the voltage detected by the voltage detection unit 12 is Vo or Vc. When the detected voltage is Vo (S30: Vo), the process proceeds to S40, and when the detected voltage is Vc (S30: Vc), the process proceeds to S50.

  When the process proceeds to S40, since the voltage detected by the voltage detection unit 12 is Vo, the lock unit 20 is determined to be in the unlocked state for the above reason. When the process proceeds to S50, since the voltage detected by the voltage detection unit 12 is Vc, it is determined that the lock unit 20 is locked for the above reason. When the process proceeds to S60, the voltage detected by the voltage detection unit 12 is neither Vc nor Vo, so it is determined that the path is abnormal. The above is the processing procedure of FIG.

In S60, the route abnormality may be determined in more detail as follows. For example, if the path abnormality is an open (open) state between the energization lines L1 and L2, the voltage detected by the voltage detection unit 12 is the next Vab1. Therefore, if the detection voltage is Vab1, it may be determined that the energization lines L1 and L2 are open.
Vab1 = V3

If the power supply V1 or V2 is in a path abnormality in which the power line V1 is short-circuited with the energization line L1, the voltage detected by the voltage detection unit 12 is the next Vab2. Therefore, if the detection voltage is Vab2, it may be determined that the power source V1 or V2 is short-circuited with the energization line L1.
Vab2 = V1 or V2

If the grounding part (GND) is in a path abnormality in which the ground line (GND) is short-circuited with the energization line L1, the voltage detected by the voltage detection part 12 is the next Vab3. Therefore, if the detection voltage is Vab3, it may be determined that the ground portion (GND) is short-circuited with the energization line L1.
Vab3 = 0 (GND)

If the switch SW6 is connected to the point A and the point C at the same time and the path is mistakenly wired to connect the point B and the point D at the same time, the voltage detected by the voltage detector 12 is the next Vab4. It becomes. Therefore, if the detection voltage is Vab4, the switch SW6 may be determined to be defective.
Vab4 = V3 * R2 / (R1 + R2)

  If the processing of FIG. 2 is executed under the system configuration of FIG. 1, the following effects can be obtained. Since the diodes D3 and D4 having opposite directions are arranged in the switch SW6, the regenerative current flows without trouble when the motor M1 rotates. Therefore, the problem that the regenerative electromotive force cannot be processed as in the conventional example of FIG. 5 can be avoided. In the conventional example of FIG. 5, the same current as when the motor M1 is rotated from the switch 10 when detecting locking / unlocking, that is, a relatively large current flows, but in the configuration of FIG. Only a minute current is supplied from the switch 11 when detecting the lock. Therefore, the load on the motor M1 at the time of locking / unlocking detection can be reduced, which contributes to power saving. In addition, since locking / unlocking is determined by voltage detection by the voltage detection unit 12, no new wiring is required for locking / unlocking detection.

  The above embodiment may be arbitrarily changed without departing from the spirit described in the claims. For example, the diodes D3 and D4 have different voltage drop values when energized, but the diodes D3 and D4 are replaced with a series connection of a plurality of (or singular) diodes (the voltage drop values when energized may be the same). In this case, the number of diodes in series may be changed to be different (that is, for example, the diode D3 is replaced with a series combination of two diodes, and the diode D4 is replaced with a series combination of three diodes). . Even in such a configuration, the voltage drop value at the time of energization can be made different by the switch SW6.

1 Electronic control unit 2 Lock mechanism 12 Voltage detector (detector)
SW6 switch (element part)

Claims (5)

A lock unit driven by the DC motor is in a locked state or an unlocked state at a position in series with the DC motor in an H-bridge circuit connected to supply electric power in both forward and reverse directions to the DC motor. Depending on whether the connection state is switched, the DC motor can flow in both forward and reverse directions regardless of whether the lock portion is locked or unlocked, and depending on whether the lock portion is locked or unlocked. And element parts with different voltage drop values,
A detection unit for detecting a potential at a point where the voltage drop value of the element unit is reflected in the H-bridge circuit;
A detection system comprising: The element portion is
A first diode part in which at least one diode is connected in series with the same energization direction and a second diode part in which at least one diode is connected in series with the same energization direction are mutually in the energization direction Are connected in parallel in opposite directions, and the voltage effect value at the time of energization differs between the first diode part and the second diode part, and
A connection control unit that switches a connection state of the diode unit in the H bridge circuit according to whether the lock unit is in a locked state or an unlocked state;
The detection system according to claim 1, comprising:   The connection control unit is configured so that the first diode unit is energized when the lock unit is locked, and the second diode unit is energized when the lock unit is unlocked. The detection system according to claim 2, wherein the diode unit is connected in a bridge circuit.   2. A current supply unit that supplies current to the element unit and the DC motor so that the DC motor does not rotate in a state where electric power is not supplied from the H-bridge circuit to the DC motor. 4. The detection system according to any one of items 1 to 3. The detection system according to claim 1, wherein the detection unit includes an abnormality determination unit that determines whether there is an abnormality in the current path according to the detected potential.

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