DEVICE FOR DETECTING THE ROTATION OF A MOTOR

Abstract

A device for detecting the rotation of a motor, the device comprising: a first switching device (21) and a second switching device (22) which are connected to a power supply (50), a third switching device (23) and a fourth switching device (24) which are connected to a ground (80), a motor (10) connected between a first node (N1), to which the first switching device (21) and the third switching device (23) are connected, and a second node (N2), to which the second switching device (22) and the fourth switching device (24) are connected, a first resistance device (31) and a second resistance device (32) arranged in an associated manner between the third switching device (23) and the ground (80) and between the fourth switching device (24) and the ground (80), and a control unit (100) configured to derive a rotation amount of the motor (10) by integrating a current flowing in the first resistance device (31) or the second resistance device (32) by means of a counter electromotive force generated when the motor decelerates, and to generate a pulse based on the rotation amount of the motor (10), wherein the control unit (100) generates an edge of the pulse at a time at which a cumulative value of an integrated current value obtained by integrating a current is greater than or equal to an initial threshold value.

Description

Background of the inventionTechnical field

[0001] The present disclosure / invention relates to a motor rotation detecting apparatus and, more particularly, to a motor rotation detecting apparatus for generating a pulse for detecting the rotation of the motor without a Hall sensor. Background technology

[0002] A stator of a motor used in a seat uses an armature that allows current to flow in a coil, and a rotor uses a permanent magnet in which N and S poles are repeatedly formed. To continuously rotate the motor, it is necessary to form a continuous rotating magnetic field of the motor. To form the continuous rotating magnetic field, the current flowing in a coil of each phase of the armature must be converted at an appropriate time. In this case, it is necessary to accurately detect the position of the rotor to determine the conversion time.

[0003] In particular, to drive the motor smoothly, it is necessary to precisely match the rotor position and the phase current conversion time. For this purpose, a Hall sensor is used to detect the rotor position on an inner surface of the motor. Due to global price competition, a cost-reducing method by removing a Hall sensor from a memory seat has been studied. This technology is called sensorless motor control technology, and its core technology is the interpretation of the current ripple generated while the motor rotates. A low-frequency component due to components of the winding resistance and the back electromotive force, and a high-frequency component due to the rotation of a commutator, are synthesized in the motor current, and accordingly, it is not easy to detect an inflection point of the ripple.

[0004] After power is supplied to the motor, ripple is stably generated in a stable state. In this case, when calculating a ripple increment, positive and negative values are repeatedly output based on 0, thereby generating a zero crossing. Using the zero crossing, it is easy to calculate the motor rotation. However, the current ripple generated after the motor decelerates is uncertain, and even if the ripple increment is calculated, it is difficult to accurately determine whether the increment is a positive value or a negative value, and accordingly, there is a problem that it is difficult to determine the motor rotation.

[0005] DE 197 42 370 A1 discloses a controller of an electric power steering system that can improve steering performance by estimating a motor angular velocity ω in the range where the angular velocity of a motor is small, and furthermore, highly accurately estimating the motor angular velocity, thus fully exhibiting the functions of compensating for motor inertia and controlling the astringency of a vehicle. Since the estimation error of a counter electromotive force between a model motor and a motor to be actually mounted is proportional to the motor current, a dead zone of a motor angular velocity, which has a width proportional to a motor current, is set to the estimated value of the motor angular velocity. When the motor current is small, the width of the dead zone also decreases.Thus, it is possible to estimate the angular velocity ω even in a region where the motor angular velocity is small. Furthermore, a motor angular velocity is estimated by defining impedance models of a motor drive system in an intermittent mode and a continuous mode. Explanation of the invention

[0006] The present invention has for its object to provide a device for detecting the rotation of a motor for determining the rotation amount of the motor using a counter electromotive force generated after the motor brakes without providing a Hall sensor.

[0007] Another object of the present invention is to provide a device for detecting the rotation of a motor for correcting a portion in which a pulse cannot be generated due to a small amount of current based on the counter electromotive force immediately after the motor brakes, based on a cycle of pulses generated before the motor brakes.

[0008] To achieve the object, the present invention provides a device for detecting the rotation of a motor (e.g., the rotation of a shaft of a motor). The device comprises: a first switching device and a second switching device, which (e.g., each of which) are connected to a power supply (e.g., a current supply, e.g., a voltage supply), a third switching device and a fourth switching device, which (e.g., each of which) are connected to a ground (e.g., an earth), a motor (e.g.,an electric motor) connected between a first node to which the first switching device and the third switching device are connected and a second node to which the second switching device and the fourth switching device are connected, a first resistance device and a second resistance device arranged in an associated manner between the third switching device and the ground and between the fourth switching device and the ground, and a control unit configured to derive a rotation amount of the motor by integrating a current flowing in the first resistance device or the second resistance device by means of a counter electromotive force generated when the motor brakes, and to generate a pulse (e.g. a pulse, e.g.a voltage pulse) based on the rotation amount of the motor, wherein the control unit generates an edge of the pulse at a time (e.g., at a time) at which a cumulative value of an integrated current value obtained by integrating a current is greater than or equal to an initial threshold value.

[0009] In one embodiment, current (e.g., a current) may flow in the second resistance device when the motor rotates in a forward direction, current (e.g., a current) may flow in the first resistance device when the motor rotates in a reverse direction, when the motor decelerates while rotating in the forward direction, the control unit may generate the pulse based on the current flowing in the first resistance device, and when the motor decelerates while rotating in the reverse direction, the control unit may generate the pulse based on the current flowing in the second resistance device.

[0010] In another embodiment, the control unit may detect the rotation of the motor until the motor decelerates based on a slope of the ripple of the current flowing in the first resistance device or the second resistance device (e.g., the control unit may detect the rotation of the motor based on a slope of the ripple of the current flowing in the first resistance device or the second resistance device until the motor decelerates).

[0011] The control unit may correct the omission of a pulse which is generated until (eg until) an integrated value of the current flowing in the first resistance device or (in) the second resistance device, which is / has been accumulated from a time (eg from a time, eg from a time, eg from a time) at which the motor is braking, is greater than or equal to an initial threshold value.

[0012] The control unit may generate the omitted pulse based on an average of cycles of pulses until the motor decelerates (e.g., the control unit may generate the omitted pulse based on an average of cycles of pulses that are / were generated until the motor decelerates).

[0013] The control unit may set (e.g., set) a value obtained by adding a preset range value to the initial threshold value after the cumulative value of the integrated current value is greater than the initial threshold value to a primary threshold value, and the control unit may generate an edge of the pulse at a time (e.g., at a time) at which the cumulative value of the integrated current value is greater than or equal to the primary threshold value after the edge of the pulse is generated.

[0014] The control unit may set a value obtained by adding the range value to the primary threshold to a secondary threshold after the edge of the pulse is / has been generated, and may generate the edge of the pulse by comparing the secondary threshold with the cumulative value of the integrated current value, and the control unit may generate the edge of the pulse by comparing a new threshold, which is continuously updated, with the cumulative value of the integrated current value.

[0015] The control unit may comprise: a current meter (e.g., a current measuring device) configured to measure the current flowing in the first resistance device or the second resistance device, an integral unit (e.g., an integrating unit) configured to derive (e.g., determine) the rotation amount of the motor, which is proportional to an integrated current value obtained by integrating the measured current, a correction logic generator configured to correct the omission of a pulse generated until a cumulative value of the integrated current value is greater than or equal to an initial threshold value from a time (e.g., from a time) at which the motor brakes, and a pulse generator (e.g.,a pulse generator) arranged to generate the pulse by comparing the cumulative value of the integrated current value with an Nth threshold value.

[0016] The pulse generator may set (e.g., set) a value obtained by adding a preset range value to an (N-1)th threshold to an Nth threshold, and may generate a new edge of the pulse at a time (e.g., at a time) at which the integrated current value accumulated after the edge of the pulse is generated is greater than or equal to the Nth threshold.

[0017] The ammeter may derive (e.g., determine) a direction of rotation before the motor brakes (decelerates) based on a resistance device in which current flows from the first resistance device and the second resistance device. Brief description of the drawings

[0018] The above and other features of the present disclosure / invention will now be described in detail with reference to certain exemplary embodiments thereof illustrated in the accompanying drawings, which are given below for illustrative purposes only and are therefore not limitative of the present disclosure / invention, and wherein: Fig. 1 is a circuit diagram for explaining the measurement of a current generated when a motor rotates in a forward direction by a motor rotation detecting device according to an embodiment of the present disclosure / invention, Fig. 2 is a circuit diagram for explaining the measurement of a current generated when a motor rotates in a reverse direction by a motor rotation detecting device according to an embodiment of the present disclosure / invention, Fig. 3 is a circuit diagram for explaining the measurement of a current generated when a motor is braking by a motor rotation detecting device according to an embodiment of the present disclosure / invention, Fig. 4 is a block diagram showing a control unit of an apparatus for detecting the rotation of a motor according to an embodiment of the present disclosure / invention, Fig. 5 is a diagram for explaining a method of detecting a rotation amount of a motor until the motor brakes according to an embodiment of the present disclosure / invention, Fig. 6 is a graph showing the integration of a current detected after the motor brakes, according to an embodiment of the present disclosure / invention, Fig. 7 is a graphical representation for explaining the generation of a pulse based on a graphical representation showing the integration of a current according to an embodiment of the present disclosure / invention, and Fig. 8 is a flowchart for explaining a method for detecting the rotation of a motor according to an embodiment of the present disclosure / invention. Detailed description

[0019] The accompanying drawings illustrating exemplary embodiments of the present disclosure / invention should be consulted in order to gain a sufficient understanding of the present disclosure / invention, its advantages, and the objects achieved by implementing the present disclosure / invention. However, the present disclosure / invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure / invention will be thorough and complete, and will fully convey the concepts of the present disclosure / invention to those skilled in the art. Furthermore, the terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting of the present disclosure / invention. Like reference characters in the drawings refer to like elements.

[0020] Terms such as “unit” or “module” etc. are to be understood as referring to units which process / execute at least one function or operation and which may be implemented in a hardware manner, in a software manner or a combination of a hardware manner and a software manner.

[0021] Terms such as “first”, “second”, and the like used in the description may be used to distinguish the relevant elements using the reference relationship and are not limited by the order.

[0022] The detailed description is used to exemplify the present disclosure / invention. The description is given herein to show exemplary embodiments of the present disclosure / invention, and the present disclosure / invention may be used in various other combinations, changes, and environments. That is, the present disclosure / invention may be changed or modified within the scope of the concept of the present disclosure / invention disclosed in the description, the equivalence range of the given disclosure / invention, and / or the scope of technology or skill in the art. The described embodiment is the ideal embodiment for implementing the technological content of the present disclosure / invention, but may be changed in various forms required for precise applications and uses of the present disclosure / invention.Therefore, the detailed description of the present disclosure / invention herein is merely exemplary and is not intended to limit the present disclosure / invention. The following claims should be interpreted to include other embodiments.

[0023] Fig. 1 is a circuit diagram for explaining the measurement of a current generated when a motor rotates in a forward direction by a motor rotation detecting device according to an embodiment of the present disclosure / invention. Fig. 2 is a circuit diagram for explaining the measurement of a current generated when a motor rotates in a reverse direction by a motor rotation detecting device according to an embodiment of the present disclosure / invention.

[0024] Referring to Fig. 1 and Fig. 2, the motor rotation detection device may be a device for replacing a Hall sensor used on an inner side (e.g., inside) of the motor to calculate the position (e.g., posture) of the motor (a rotation angle or a track position) of a memory seat. The motor rotation detection device may generate a pulse (e.g., a pulse, e.g., a voltage pulse) to detect the position of the motor (e.g., the electric motor) without an original Hall sensor.

[0025] The motor rotation detection device may include a motor (e.g., an electric motor) 10, H-bridge circuits 21, 22, 23, 24, 31, and 32, and a control unit (not shown). The motor rotation detection device may utilize the current flowing in resistance devices 31 and 32, which is applied to the H-bridge circuits 21, 22, 23, 24, 31, and 32, to generate a pulse. The control unit (not shown) may be an electronic control unit (ECU) for controlling the drive of a seat.

[0026] The H-bridge circuits 21, 22, 23, 24, 31, and 32 may include: a first switching device 21 and a second switching device 22 connected to a power supply (e.g., a current supply, e.g., a voltage supply) 50; a third switching device 23 and a fourth switching device 24 connected to a ground (e.g., an earth) 80; a first resistance device 31 disposed between the third switching device 23 and the ground 80; and a second resistance device 32 disposed between the fourth switching device 24 and the ground 80. A point to which the first switching device 21 and the third switching device 23 are connected may be defined as a first node N1, and a point to which the second switching device 22 and the fourth switching device 24 are connected may be defined as a second node N2.The motor 10 may be arranged (e.g., arranged and connected) between the first node N1 and the second node N2 and may be connected to the first switching device 21, the second switching device 22, the third switching device 23, and the fourth switching device 24.

[0027] The motor 10 can be used in a seat for a vehicle and can enable the motor 10 to rotate in a forward and reverse direction according to a switch manipulation (e.g., a switch operation) of an occupant (e.g., by an occupant). According to the occupant's switch manipulation, when the first switching device 21 and the fourth switching device 24 are turned on and the second switching device 22 and the third switching device 23 are turned off, the motor 10 can rotate in a forward direction. In this case, a current can flow in the second resistance device 32, and the control unit (not shown) can measure the current flowing in the second resistance device 32.When the first switching device 21 and the fourth switching device 24 are turned on, a current can flow to the second resistance device 32 from the power supply 50 through the first switching device 21, through the motor 10, and through the fourth switching device 24.

[0028] According to the occupant's switch manipulation, when the second switching device 22 and the third switching device 23 are turned on and the first switching device 21 and the fourth switching device 24 are turned off, the motor 10 may rotate in a reverse direction. In this case, current may flow to the first resistance device 31, and the control unit (not shown) may measure the current flowing in the first resistance device 31. When the second switching device 22 and the third switching device 23 are turned on, current may flow to the first resistance device 31 from the power supply 50 through the second switching device 22, the motor 10, and the third switching device 23.

[0029] The control unit (not shown) can measure a resistance device in which current flows from the first resistance device 31 and the second resistance device 32 and can determine whether the motor 10 is currently rotating in a forward or reverse direction.

[0030] Fig. 3 is a circuit diagram for explaining the measurement of a current generated when a motor is decelerating by a motor rotation detecting device according to an embodiment of the present disclosure / invention. For brevity, a repeated description is omitted.

[0031] With reference to Fig. 1 to Fig. 3, when the motor 10 decelerates while operating in a forward direction (e.g., running, e.g., rotating), a counter electromotive force may be generated and a current may flow in a direction 2. The current may flow to the first resistance device 31 from the motor 10 through the third switching device 23, and the control unit (not shown) may measure the current flowing in the first resistance device 31. Accordingly, the control unit (not shown) may determine that the motor 10 decelerates while operating in a forward direction (e.g., running, e.g., rotating).

[0032] When the motor 10 decelerates while operating in a reverse direction (e.g., running, e.g., rotating), a counter electromotive force may be generated and a current may flow in a direction 1. The current may flow to the second resistance device 32 from the motor 10 through the fourth switching device 24, and the control unit (not shown) may measure the current flowing in the second resistance device 32. Accordingly, the control unit (not shown) may determine that the motor 10 is decelerating while operating in a reverse direction (e.g., running, e.g., rotating).

[0033] Fig. 4 is a block diagram showing a control unit of an apparatus for detecting rotation of a motor according to an embodiment of the present disclosure / invention.

[0034] Referring to Fig. 3 and Fig. 4, a control unit 100 can derive (e.g., determine) a rotation amount (e.g., a rotation angle, e.g., a rotation distance) of the motor 10 based on a back electromotive force generated when the motor 10 is decelerating, and can therefore generate a pulse based on the rotation amount of the motor 10. Specifically, the rotation amount of the motor 10 can be derived (e.g., determined) by integrating the current flowing in the first resistance device 31 or the second resistance device 32 by the back electromotive force (e.g., the current flowing in the first resistance device 31 or the second resistance device 32 by the back electromotive force) generated when the motor 10 is decelerating, and the pulse can be generated based on the rotation amount of the motor 10.When the motor 10 rotates in a forward direction, current may flow in the second resistance device 32, and when the motor 10 rotates in a reverse direction, current may flow in the first resistance device 31. When the motor 10 decelerates while operating in a forward direction (e.g., running, e.g., rotating), the control unit 100 may generate a pulse based on the current flowing in the first resistance device 31. When the motor 10 decelerates while operating in a reverse direction (e.g., running, e.g., rotating), the control unit 100 may generate a pulse based on the current flowing in the second resistance device 32.The pulse generated by the control unit 100 may be similar to a pulse generated by a Hall sensor, and therefore, according to an embodiment of the present disclosure / invention, the control unit 100 may generate a pulse for determining the rotation amount of the motor 10 even when no Hall sensor is present. The control unit 100 may determine the rotation amount of the motor based on the current generated by the counter electromotive force after determining (e.g., after the control unit 100 has determined) whether the motor 10 is operating in a forward or reverse direction (e.g., running, e.g., having operated, e.g., running) before braking.

[0035] The control unit 100 may include an ammeter (e.g., a current measuring device) 110, an integral unit (e.g., an integrating unit) 120, a pulse generator (e.g., a pulse generator) 130, and a correction logic generator 140. The ammeter 110, the integral unit 120, the pulse generator 130, and the correction logic generator 140 may be configured by classifying the control unit 100 depending on their functions and do not need to be physical components of the control unit 100.

[0036] The ammeter 110 can measure the current flowing in the first resistance device 31 or the second resistance device 32. The ammeter 110 can detect a direction in which the motor 10 rotates before braking based on a resistance device in which current flows from the first resistance device 31 and the second resistance device 32.

[0037] The integration unit 120 can integrate the current measured by the ammeter 110. The motor 10 can be operated using the following equation. Vin=Ri+L⋅didt+ee=KeW

[0038] Here is V in a voltage applied to the motor 10, is the current, is R i is the resistance, L is the inductance, e is the counter electromotive force, K is e is the counter electromotive force constant and W is a speed of the motor.

[0039] The voltage applied to the motor 10 when the motor 10 is braking can be 0 (e.g. zero), and the current i when the motor 10 is braking can be a current i generated by the counter electromotive force. e be. 0=R⋅ie+L⋅diedt+e

[0040] In this case, a voltage generated by / by means of a coil can be neglected.

[0041] The current ie when the motor 10 brakes, can be proportional to the speed of the motor 10 and the amount of rotation of the motor 10, which is obtained by integrating the speed of the motor 10, can be obtained by integrating the current i e be derived (e.g. determined). ie=−eR=−KeWR

[0042] Then, a current value obtained by integration by means of the integral unit 120 can be used as an integrated current value i e be defined.

[0043] The pulse generator 130 can generate a pulse by generating a cumulative value of the integrated current value i e when the motor 10 brakes, which is proportional to the rotational amount of the motor 10, with a threshold value. The pulse generator 130 can calculate the cumulative value of the integrated current value i ewith the threshold value and can generate the pulse at the time (e.g. at the time) at which the cumulative value of the integrated current value i e is greater than or equal to the threshold value. The threshold value may refer to an experimentally derived (e.g., determined) value. In particular, the pulse generator 130 may generate an edge of the pulse at the time (e.g., at the time) at which the cumulative value of the integrated current value i e is greater than or equal to an initial threshold value (e.g., an initial threshold value). Immediately after the motor 10 brakes, the cumulative value of the integrated current value i e excessively small, and therefore, when the cumulative value of the integrated current value i eis smaller than the initial threshold value, the pulse generator 130 may have difficulty generating the pulse. Accordingly, the pulse generator 130 may generate the pulse from the time (e.g., from the time) at which the cumulative value of the integrated current value i e is greater than or equal to the initial threshold.

[0044] The pulse generator 130 may generate a value obtained by adding a preset range value to the initial threshold value after the time at which the cumulative value of the integrated current value i egreater than the initial threshold value is obtained, to a primary threshold value (e.g., set, e.g., the primary threshold value can be set / adjusted to this value). The preset range value can be derived (e.g., determined) based on a current value applied to the motor 10 to allow a Hall sensor to generate 1 pulse (e.g., one pulse) when the rotation of the motor 10 is measured. That is, the preset range value can refer to an experimentally derived (e.g., determined) constant. The pulse generator 130 can continuously update the threshold value to continuously generate pulses. The pulse generator 130 can generate the pulse by calculating the cumulative value of the integrated current value i e, which is proportional to the rotation amount of the motor 10, with an (N-1)-th threshold value. The pulse generator 130 may generate an N-th edge at the time (e.g., at the time) at which the cumulative value of the integrated current value i e is greater than or equal to the (N-1)th threshold. After the Nth edge is / has been generated, the pulse generator 130 may set (e.g., adjust) the Nth threshold by adding the preset range value to the (N-1)th threshold. The pulse generator 130 may generate an (N+1)th edge of the pulse at the time at which the integrated current value i e, which is / has been accumulated after the Nth edge of the pulse is / has been generated, is greater than or equal to the Nth threshold. The pulse generator 130 may continue to update a threshold and generate an edge of the pulse by the previously described method until the back electromotive force of the motor 10 is 0 (e.g., zero).

[0045] The correction logic generator 140 can correct the omission (e.g., absence) of a pulse which is generated until the integrated current value i e , which is / has been accumulated from the time the motor 10 decelerates, is greater than or equal to the initial threshold value. Immediately after the motor 10 decelerates, the current generated by the counter electromotive force may be excessively small. Therefore, the pulse generator 130 cannot generate a pulse if the cumulative value of the integrated current value i eis excessively small (e.g., it is possible that the pulse generator 130 does not generate a pulse when the cumulative value of the integrated current value i eis excessively small). The correction logic generator 140 may generate the omitted pulse based on an average of cycles of pulses derived (e.g., determined) until the motor 10 decelerates. Until the motor 10 decelerates, the controller 100 may determine the rotation of the motor 10 based on a change in the slope of the ripple of the current flowing in the first resistance device 31 or the second resistance device 32. That is, the controller 100 may set (e.g., adjust) the slope of the current ripple to 0 (e.g., zero) when power is supplied to the motor 10, and may generate a pulse depending on whether the slope of the current ripple has a positive value or a negative value based on 0 (e.g., zero).Accordingly, the correction logic generator 140 may generate the omitted pulse using the average of the pulses that are / were generated until the motor 10 decelerates.

[0046] According to one embodiment of the present disclosure / invention, the control unit 100 of the motor rotation detection device can generate a pulse based on an integrated current value after the motor 10 decelerates, without a Hall sensor. The rotation amount can be derived (e.g., determined) based on the pulse generated by the control unit 100, thereby reducing manufacturing costs due to the omission (e.g., elimination) of a Hall sensor.

[0047] According to one embodiment of the present disclosure / invention, the motor rotation detecting device can correct omitted (e.g., omitted) portions of the pulse generated based on the integrated current value based on the pulse before the motor 10 decelerates. Therefore, the motor rotation detecting device can prevent an error in determining the rotation amount of the motor 10 due to the omitted pulse.

[0048] Fig. 5 is a diagram for explaining a method of detecting a rotation amount of a motor until the motor decelerates according to an embodiment of the present disclosure / invention. Fig. Figure 5 represents the case where the motor brakes while rotating in a forward direction.

[0049] Referring to Fig. 4 and Fig. 5, the control unit 100 may generate a pulse based on a current change measured while the motor is operated in a forward direction (e.g., based on the change in current measured while the motor is operated in a forward direction). Specifically, the control unit 100 may set (e.g., adjust) a slope of the current ripple at the time power is applied to the motor to 0 (e.g., zero) and may infer (e.g., determine) whether the slope of the current ripple has a positive value or a negative value based on 0 (e.g., zero) to generate the pulse.

[0050] The current may be generated by the counter electromotive force after the motor decelerates, and therefore, the slope of the current ripple measured by the control unit 100 may have a negative value. Therefore, the control unit 100 may not generate a pulse by the slope of the current ripple after the motor decelerates, and may not detect motor rotation (e.g., it is possible that the control unit 100 does not generate a pulse by the slope of the current ripple after the motor decelerates, and it is possible that the control unit 100 does not detect motor rotation).

[0051] Fig. 6 is a graph showing the integration of the current detected after the motor decelerates, according to one embodiment of the present disclosure / invention. Fig. 6 represents the case where the motor brakes while rotating in a forward direction.

[0052] Referring to Fig. 4 and Fig. 6, the ammeter 110 can measure the current generated by the back electromotive force after the motor brakes. The integral unit 120 can derive (e.g., determine) the rotational speed of the motor by integrating the current generated by the back electromotive force. In this case, the derived rotational speed (e.g., the determined rotational speed) of the motor does not have a pulse shape, and therefore, it may be difficult to intuitively determine the rotational speed of the motor. An integrated current value, which is a value obtained by integrating the current, can be proportional to the rotational speed of the motor and Fig. 6, the y-axis refers to the rotation amount of the motor and the integrated current value.

[0053] Fig. 7 is a graphical representation for explaining the generation of a pulse based on a diagram showing the integration of the current according to an embodiment of the present disclosure / invention.

[0054] Referring to the Fig. 4 and Fig. 7, the pulse generator 130 may generate the pulse based on the integrated current value derived (e.g., determined) by the integral unit 120 after the time at which the motor decelerates. The pulse generator 130 may generate a primary edge of the pulse at a first time P1 at which a cumulative value of the integrated current value is greater than or equal to an initial threshold value T1. The pulse generator 130 may set a value obtained by adding the preset range value to the initial threshold value T1 after the first time P1 to a primary threshold value T2. The pulse generator 130 may determine whether the integrated current value accumulated after the first time P1 is greater than or equal to the primary threshold value T2.The pulse generator 130 may generate a secondary edge of the pulse at a second time P2 at which the integrated current value accumulated after the first time P1 is greater than or equal to the primary threshold value T2.

[0055] The pulse generator 130 may set (e.g., adjust) a value obtained by adding the preset range value to an (N-1)th threshold after an Nth edge of the pulse is / has been generated to an Nth threshold. The pulse generator 130 may continuously generate pulses until the integrated current value is not greater than or equal to the Nth threshold. A cycle of pulses generated by the pulse generator 130 may be increased until the motor is driven again after the motor decelerates (e.g., has decelerated).

[0056] The correction logic generator 140 may correct the omitted pulse until a cumulative current value from the time (e.g., from the time) at which the motor decelerates is greater than or equal to the initial threshold T1. The correction logic generator 140 may generate the omitted pulse based on the average of cycles of pulses that are / have been derived (e.g., determined) until the motor decelerates (e.g., has decelerated). Immediately after the motor decelerates, a rotational speed before deceleration may be maintained for a predetermined time (e.g., a predetermined time) or may not be drastically reduced (e.g., it is possible that it is / will not be drastically reduced). Accordingly, the correction logic generator 140 may derive (e.g., determine) the omitted pulse based on the average of the pulses that are / have been derived (e.g., determined) before the motor decelerates (e.g.,has braked), and (the correction logic generator 140) can reduce an error in detecting the amount of rotation of the motor.

[0057] Fig. 8 is a flowchart for explaining a method for detecting the rotation of a motor according to an embodiment of the present disclosure / invention.

[0058] Referring to Fig. 8, the logic for determining the rotation amount of the motor can be changed based on the time at which the motor decelerates. Whether the motor is decelerating can be determined by the control unit based on a direction in which the motor rotates before the motor decelerates and a resistance device in which current flows, among resistance devices arranged in an H-bridge of a motor rotation detection device (S100).

[0059] The rotation of the motor can be detected based on the current ripple slope flowing in the resistance device until the motor decelerates. The control unit can generate a pulse depending on whether the current ripple slope is positive or negative, based on a reference value when the motor decelerates. The rotational speed of the motor can be detected (e.g., determined) based on the generated pulse (S200 and S300).

[0060] After the motor decelerates (e.g., has decelerated), the control unit can detect (e.g., determine) the motor's rotational speed based on the current generated by the counter electromotive force. First, the control unit can integrate the motor's current using the counter electromotive force (e.g., the motor current generated by the counter electromotive force) (S400).

[0061] The control unit may determine whether the cumulative value of the integrated current value, which is a value obtained by integrating a current, is greater than or equal to the initial threshold. Until the cumulative value of the integrated current value is greater than or equal to the initial threshold, the control unit may not generate the pulse based on the integrated current value (e.g., the control unit may not generate the pulse based on the integrated current value). That is, the pulse may be omitted between the time the motor decelerates and the time the cumulative value of the integrated current value is greater than or equal to the initial threshold (S500).

[0062] The control unit can derive (e.g., determine) the missed pulse based on an average of the pulse cycles before the motor decelerates. The control unit can derive (e.g., determine) the pulse in real time based on the average of the pulse cycles before the motor decelerates from the time (e.g., from the time) at which the motor decelerates (S600).

[0063] The control unit may generate a new edge at the time the cumulative value of the integrated current value is greater than or equal to the initial threshold. The control unit may set a value obtained by adding a preset range value to the initial threshold after an edge is generated (e.g., the control unit may set the new threshold thereon). The control unit may continuously set the new threshold after the new edge is generated (e.g., set) (S700).

[0064] The control unit can generate an edge while continuously updating the threshold. The control unit can continuously generate pulses by comparing the threshold with the sum of the integrated current values after the new edge is / has been generated (S800).

[0065] According to one embodiment of the present disclosure / invention, the motor rotation detecting device can generate a pulse based on an integrated current value after the motor decelerates without a Hall sensor. The rotation amount of the motor can be inferred (e.g., determined) based on the pulse generated by the motor rotation detecting device, thereby reducing manufacturing costs due to the omission (e.g., elimination) of a Hall sensor.

[0066] According to one embodiment of the present disclosure / invention, the motor rotation detecting device can correct omitted portions of the pulse generated based on the integrated current value based on the pulse that is derived (e.g., determined) before the motor decelerates. Therefore, the motor rotation detecting device can prevent an error in determining the rotation amount of the motor due to the omitted pulse.

Claims

[1] A device for detecting the rotation of a motor, the device comprising: a first switching device (21) and a second switching device (22) which are connected to a power supply (50), a third switching device (23) and a fourth switching device (24) which are connected to a ground (80), a motor (10) connected between a first node (N1), to which the first switching device (21) and the third switching device (23) are connected, and a second node (N2), to which the second switching device (22) and the fourth switching device (24) are connected, a first resistance device (31) and a second resistance device (32) arranged in an associated manner between the third switching device (23) and the ground (80) and between the fourth switching device (24) and the ground (80), and a control unit (100) configured to derive a rotation amount of the motor (10) by integrating a current flowing in the first resistance device (31) or the second resistance device (32) by means of a counter electromotive force generated when the motor decelerates, and to generate a pulse based on the rotation amount of the motor (10), wherein the control unit (100) generates an edge of the pulse at a time at which a cumulative value of an integrated current value obtained by integrating a current is greater than or equal to an initial threshold value. [2] Device according to claim 1, wherein: Current flows in the second resistance device (32) when the motor (10) rotates in a forward direction, Current flows in the first resistance device (31) when the motor (10) rotates in a reverse direction, when the motor (10) decelerates while rotating in the forward direction, the control unit (100) generates the pulse based on the current flowing in the first resistance device (31), and when the motor (10) decelerates while rotating in the reverse direction, the control unit (100) generates the pulse based on the current flowing in the second resistance device (32). [3] The apparatus according to claim 1 or 2, wherein the control unit (100) detects the rotation of the motor (10) until the motor (10) decelerates based on a slope of the ripple of the current flowing in the first resistance device (31) or the second resistance device (32). [4] The device according to any one of claims 1 to 3, wherein the control unit (100) corrects the omission of a pulse generated until an integrated value of the current flowing in the first resistance device (31) or the second resistance device (32), which is accumulated from a time at which the motor (10) decelerates, is greater than or equal to an initial threshold value. [5] The apparatus of claim 4, wherein the control unit (100) generates the omitted pulse based on an average of cycles of pulses until the motor decelerates. [6] Device according to any one of claims 1 to 5, wherein: the control unit (100) sets a value obtained by adding a preset range value to the initial threshold value after the cumulative value of the integrated current value is greater than the initial threshold value to a primary threshold value, and the control unit (100) generates an edge of the pulse at a time at which the cumulative value of the integrated current value is greater than or equal to the primary threshold value after the edge of the pulse is generated. [7] Device according to claim 6, wherein: the control unit (100) sets a value obtained by adding the range value to the primary threshold value to a secondary threshold value after the edge of the pulse is generated, and generates the edge of the pulse by comparing the secondary threshold value with the cumulative value of the integrated current value and the control unit (100) generates the edge of the pulse by comparing a new threshold value, which is continuously updated, with the cumulative value of the integrated current value. [8] Device according to any one of claims 1 to 7, wherein the control unit (100) comprises: an ammeter (110) configured to measure the current flowing in the first resistance device (31) or the second resistance device (32), an integral unit (120) arranged to derive the rotation amount of the motor (10) which is proportional to an integrated current value obtained by integrating the measured current, a correction logic generator (140) configured to correct the omission of a pulse generated until a cumulative value of the integrated current value is greater than or equal to an initial threshold value from a time at which the motor (10) decelerates, and a pulse generator (130) configured to generate the pulse by comparing the cumulative value of the integrated current value with an Nth threshold value. [9] The device according to claim 8, wherein the pulse generator (130) sets a value obtained by adding a preset range value to an (N-1)th threshold value to an Nth threshold value and generates a new edge of the pulse at a time at which the integrated current value accumulated after the edge of the pulse is generated is greater than or equal to the Nth threshold value. [10] The apparatus according to claim 8 or 9, wherein the ammeter (110) derives a direction of rotation before the motor (10) decelerates based on a resistance device (31, 32) in which current flows, of the first resistance device (31) and the second resistance device (32).

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