KR101330152B1 - Method of controlling a motor in a motorized seat belt - Google Patents

Abstract

The present invention relates to a method for controlling a motor in a motorized seat belt to secure safety for vehicles by enabling drivers to respond to various incidents while driving. To achieve this purpose, the present invention comprises a danger operation step, an operation maintaining step, an unlocking standby step, an unlocking determining step, and an unlocking step in operating and unlocking a motorized seat belt device. [Reference numerals] (AA,CC,DD,GG,KK) Emergency state condition detected ?;(BB) Certain period of time elapsed;(EE) �t passed ?;(FF) Second threshold current reached ?;(HH) Gradual decrease in current;(II) Gradual increase in current;(JJ) First threshold current reached ?;(LL) Spike in current;(s1) Non-activity step;(s2) Emergency activity step (spike in current);(s3) Activity maintaining step;(s4) Dismantlement standby step;(s5) Dismantlement determination step;(s6) Lifting step;(s7) Clutch lifting step (reverse direction current)

Description

Method of controlling a motor in a motorized seat belt

The present invention relates to a method of controlling a motor in a motor type seat belt for a vehicle, and more particularly, a motor type seat belt capable of coping with various unexpected situations occurring during driving of a vehicle to further secure vehicle driving safety. Relates to a method of controlling a motor.

All vehicles are fitted with Seat Belt devices that protect the occupants. Due to the development of technology, such a seat belt device has also been used in an electronically controlled motorized seat belt device in recent years. Such a motorized seat belt device is connected to various sensors so that when a vehicle crashes, the belt is strongly pulled out immediately before the collision to prevent a collision or to eliminate belt looseness that may occur when driving on a curve. It has a more protective function. In addition, the vehicle has a belt parking function that rewinds the seat belt after the passenger unwinds the seat belt, which makes the vehicle convenient.

Among the various functions of the motorized seat belt device, in particular, a function to secure the safety of the vehicle occupant in preparation for a vehicle crash situation or a sudden deceleration situation for preventing a vehicle crash is important. That is, it is possible to further protect the occupant by inserting the seat belt immediately in the sudden deceleration (hazardous situation) such that there is no looseness in the relationship with the occupant. The motorized seat belt apparatus also reduces tension and releases the belt, i.e., locks, in case of escape from the dangerous situation, thereby preventing the discomfort of the occupant due to the belt compression to persist.

Since the operation of such a motorized seat belt involves a direct action on a human, there is a great need for minimizing discomfort as well as safety in the operation. That is, as described above, when the vehicle is in a dangerous situation, the tension is increased, and when the dangerous situation is solved again, the situation is also understood by itself to reduce the tension again, and in addition to unlocking the seat belt locking device. A series of actions should be made without discomfort while ensuring maximum occupant safety. However, while the prior arts disclose a control method of such a motorized seat belt, they do not disclose an active control method capable of coping with various situations. Especially in the control logic to cope with various unexpected situations, such as immediately after the end of the dangerous situation, if the dangerous situation reappears, or if the dangerous situation occurs again during the belt release operation, the tension is increased again. It is not disclosed, and it has a disadvantage that it does not sufficiently protect the occupants.

The present invention has been made in view of the problems of the prior arts, and an object thereof is to provide a motor control method of a motor seat belt mounted on a vehicle.

It is also an object of the present invention to provide a motor control method of a motorized seat belt that can be unlocked of the seat belt while actively coping with a sudden situation by providing various control steps.

The present invention for achieving the above object is a motor including at least an electric motor capable of driving the belt spool in the pull-in direction of the belt webbing, and a seat belt locking device for suppressing the belt spool rotation in the belt webbing pull-out direction A method of controlling a motor of a seat belt, comprising: a dangerous operation step of monitoring a state of a vehicle to immediately increase a supply current amount of an electric motor to draw in a belt and generate tension of a belt when a dangerous state is detected; An operation maintaining step of maintaining a supply current amount at a constant level when the dangerous operation step is completed and the dangerous state is continued; A release waiting step of waiting for a predetermined time to release the belt tension when the dangerous state begins to be released in the operation maintaining step, and returning to the operation maintaining step when the dangerous state is maintained or reoccurs; A release determination step of increasing the supply current of the motor step by step when the waiting state is over and the dangerous state is not found in the release waiting step, and decreasing the supply current of the electric motor step by step when the dangerous state is found; And if it is detected in the release determination step that the dangerous condition has been eliminated, immediately releasing the belt locking by increasing the supply current of the electric motor, and immediately after the release, reducing the supply current again to release the tension of the belt. It is characterized by including.

In addition, in the method of controlling the motor of the motorized seat belt, the detection of the dangerous state is X acceleration sensor, Y acceleration sensor, Yaw rate sensor, Wheel speed sensor, Steering angle sensor, A brake pressure sensor, a buckle sensor, a roll-over (Roll-Over) sensor, a collision sensor, lane departure sensor, characterized in that made based on any one or more means of the front and rear radar.

In addition, in the method of controlling the motor of the motorized seat belt, the motorized seat belt includes a clutch for transmitting the rotational force of the electric motor to the belt spool, the method of controlling the motor of the motorized seat belt in the release step When the tension of the belt is released, the clutch may further include a clutch release step of releasing the clutch by rotating the electric motor in reverse.

Further, in the method of controlling the motor of the motorized seat belt, in the clutch release step, the release of the clutch periodically attempts to release the clutch until its success, and the periodic attempt gradually reverses the force by applying a stronger force. Characterized in that.

In addition, in the method of controlling the motor of the motorized seat belt, the increase in the motor supply current in the release determination step is increased step by step in the first current unit up to the first threshold current, the decrease in the motor supply current is the second threshold It characterized in that the step by step to reduce the current to the second current unit.

The method of controlling the motor of the motor-type seat belt of the present invention increases the adhesion between the seat belt and the occupant by introducing the seat belt when the vehicle is in a dangerous state, thereby increasing safety and convenience in driving the vehicle.

In addition, the method of controlling the motor of the motor-type seat belt of the present invention is to ensure that a certain level of torque is maintained in the motor by determining when the dangerous situation persists or when the dangerous situation reoccurs, thereby further securing the safety of the vehicle occupant. can do.

In addition, the method of controlling the motor of the motor-type seat belt of the present invention has an effect of further ensuring the safety of the vehicle occupant since the seat belt is unlocked at the safest time.

In addition, the method of controlling the motor of the motor-type seat belt of the present invention has the effect of reducing the power consumption of the seat belt motor by intelligently determining the situation to control the motor.

1 is a system diagram of a motorized seat belt including an in-vehicle sensor to which the present invention is applied;
Figure 2 shows the motor control method for each step of the method of controlling the motor of the motorized seat belt according to the present invention as a relationship between time and current,
3 is a motor control method including a case in which a risk is detected in a release determination step and a current decreases in each method of controlling a motor of a motorized seat belt according to the present invention as a time and current relationship. Illustration,
4 is a flowchart illustrating a method of controlling a motor of a motorized seat belt according to the present invention.

Referring to the principle of operation of the motorized seat belt device as follows. First, a vehicle seat belt is generally equipped with a seat belt locking device. This device locks the belt spool so that it does not rotate in the direction that the seat belt is pulled out for the safety of the occupant in the event of a dangerous situation. The principle of detecting a dangerous situation and operating the locking function may vary, but for example, may be operated by a physical sensor such as a ball provided in the locking device. That is, when the vehicle is subjected to a force of a certain acceleration or more, the ball located in the ball storage portion is inclined in a specific direction, and at this time, the ball strikes the trigger to operate the seat belt locking. When the seat belt is locked in this manner, the seat belt spool can no longer rotate in the drawing direction, but can only rotate in the drawing direction.

Regardless of the operation of the seat belt locking device, one or more sensors attached to the vehicle, for example, various acceleration sensors or roll-over sensors such as vehicle wheel speed, X direction acceleration, Y direction acceleration, and the like The vehicle is at risk, for example, just before a crash, by a variety of sensors such as collision sensors, yaw rate sensors, steering angle sensors, brake pressure sensors, radar, buckle sensors, and lane departure sensors. If it is determined whether the vehicle is under rapid acceleration, rapid deceleration, lane departure, collision, etc., the motor control unit uses the motor of the seat belt retractor to apply the seat belt to the proper force. Pull it. By pulling the seat belt in such a dangerous situation, the seat belt and the occupant may be increased, and the locking device may be operated as a means of securing the safety of the occupant together with the operation of the locking device. In this case, the control of the motor is performed through current control through a PWM signal by the motor control device, and the motor seat belt device is generally provided with a clutch, which is a device for transmitting or disconnecting power of the seat belt motor to the belt spool.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a system diagram of a motorized seat belt in a vehicle to which a method for controlling a motor of a motorized seat belt according to the present invention can be applied as an example. As shown in the figure, when the various sensors 300 in the vehicle detect an acceleration situation or a dangerous situation of the vehicle and send an input signal to the motor control apparatus 100, the motor control apparatus interprets the situation based on the situation. To control the seat belt motor 200 through the current to match. At this time, the seat belt motor 200 may transmit information such as torque or rotational speed back to the motor control apparatus in the form of a current.

The illustration in FIG. 1 of the in-vehicle sensor 300 is merely an example enumeration, so in practice the sensors implemented in any particular vehicle may be more or less than shown. In the description of the sensors, first, the X and Y acceleration sensors are sensors that detect accelerations in the vehicle traveling direction and the perpendicular direction on the ground plane, respectively, and the yaw rate sensor is a vehicle perpendicular to the ground plane. The sensor detects the rotational acceleration when rotating about the in-axis (Z axis), and the wheel speed sensor is a sensor that measures the rotational speed of each wheel of the vehicle. Steering Each sensor detects the steering angle, steering speed and steering direction of the vehicle, and the brake pressure sensor measures the strength of the driver's brakes by measuring the pressure. . The buckle sensor detects whether the seat belt buckle in the vehicle is locked or unlocked, and the roll-over sensor detects a situation such as the vehicle overturning, that is, the vehicle is in the X axis (axis in line with the vehicle driving direction). The rotational acceleration is detected when rotating based on the rotational speed. The collision sensor detects a collision of the vehicle, and the lane departure sensor detects whether the driving direction deviates from the lane direction on the road and the degree of departure. The front radar and the rear radar are sensors that detect whether there is an obstacle in a corresponding direction by using a radar signal.

2 is a diagram illustrating a control algorithm based on the amount of current supplied by the motor control apparatus 100 to the seat belt motor 200 in the method of controlling the motor of the motor seat belt according to the present invention. It is a time relationship diagram. Here, the x axis represents the passage of time and the y axis represents the amount of current supplied from the motor control apparatus 100 to the motor 200. The torque of the motor appearing according to the supply of the motor current is generally increased and decreased in proportion to the amount of current supplied to the motor. 4 is a flowchart illustrating a method of controlling a motor of a motorized seat belt according to the present invention. Hereinafter, the control signals of the motor control apparatus for each step shown in FIG. 2 will be described with reference to each step in the flowchart of FIG. 4.

First, there is an inactive step s1 in which the motorized seat belt device operates like a normal seat belt device with no dangerous condition found and the seat belt motor is clutched off. When one or more of the above-described in-vehicle sensor 300 detects a specific dangerous condition condition in the non-operating step s1, the motor control apparatus immediately transitions to the dangerous operating step s2. As shown in FIG. 2, in this case, the motor control apparatus 100 transmits a rapidly increasing current to the seat belt motor 200 to rapidly transmit the torque of the motor to an experimentally determined threshold current value for a time of, for example, 50 ms. The seat belt motor is rotated at a high speed in the inlet direction of the seat belt. Before the dangerous operation step, that is, the non-operating step (s1) in which no situation in which the seat belt motor 200 is operated occurs, the clutch of the seat belt device is released as described above. As the seat belt motor 200 rotates in the forward direction (belt inlet direction), the clutch is directly switched to a clutch on state, that is, a state in which the rotational force of the motor 200 is transmitted to the belt spool. As a result, in the dangerous operation step (s2), the seat belt is introduced at a high speed by the seat belt motor 200 to increase the adhesion between the occupant and the seat belt and firmly restrain the occupant to secure the safety of the occupant from the dangerous situation. In addition, as described above, the seat belt locking device is generally operated at this stage, so that the occupant restraint is also performed by the locking device. Here, the operation principle of the operation in which the clutch is automatically switched to the clutch on state by the forward rotation will be by the known art and will not be described in detail because it is irrelevant to the nature of the present invention.

The dangerous operation step s2 only lasts for a specific time and transitions to the operation maintenance step s3, which may be, for example, about 100 ms. When the dangerous operation step s2 ends and the operation maintenance step s3 is passed, the motor control device maintains a current at a certain level, as shown in FIG. 2, and at the same time based on the input signal of the sensor 300 in the vehicle. It continuously monitors whether the vehicle is in danger or has ended, for example at intervals of 5 ms. In the operation maintaining step s3, it is desirable to keep the amount of current smaller than in the dangerous operation step as shown in FIG. 2, but not to drop the torque of the motor, in order to reduce the power consumption, and the occupant restraint is Since this configuration can also be performed by the belt locking device, it will be said that there is no problem in the security of the occupant even with this configuration. As a result of the monitoring, if the dangerous state is not over, the operation maintaining step (s3) is continued by the motor control apparatus 100 and maintains the torque of the seat belt motor 200 and the tension of the seat belt, thereby continuing the occupant protection operation. Done. On the other hand, if it is sensed that the end of the dangerous state is transitioned to the next waiting wait phase (s4).

As shown in FIG. 2, the motor control device 100 maintains the same amount of current as in the operation maintaining step in the release waiting step s4, and thus the torque of the seat belt motor 200 is also maintained at the same level. Even if the dangerous state is released by the signals of the in-vehicle sensors 300, it is dangerous to release the tension of the seat belt immediately by reducing the torque in that the dangerous state continues immediately before the seat. It is to once again determine whether the belt tension is released. Therefore, the motor control apparatus 100 also monitors the signals of the sensor 300 in the vehicle and waits at periodic intervals, for example, at intervals of 5 ms, in the waiting for release phase s4. During the specific time Δt, the release waiting step s4 is continued and thereafter, the process goes to the release determination step s5, wherein in the meantime, if the dangerous state condition is detected as the dangerous operation step level, The process goes back to the operation maintenance step s3. As another embodiment, if it is determined through the periodic monitor that the risk has reoccurred in a dangerous condition condition similar to that of the dangerous operation step s2, the process returns to the operation maintaining step s3, where the dangerous state is less than that. If it is determined that there is still a condition or a risk, the waiting for release step s4 continues, and finally, if it is determined that the dangerous condition has disappeared, a method of moving to the release determination step s5 may be assumed.

The next step, the release determination step (s5) is a step in which preparation work for releasing the seat belt is performed. If a risk factor is not found by periodically determining, for example, a dangerous state condition at intervals of about 5 ms, a certain limit is established. It is desirable to increase the amount of motor supply current in steps up to the numerical value (first threshold current). The reason for this is that in the release step s6, as shown in FIG. 2, the supply current is rapidly increased and the tension of the motor is momentarily increased to release the belt locking. If it is determined that the risk factor has disappeared, the belt is unlocked. Since it is also a safe situation, it is to increase the motor supply current in advance in the release determination step (s5) to accumulate electrical energy in the motor to release the unlocking more quickly in the next step, the release step. In addition, by gradually increasing the torque in advance prior to the releasing step (s6) to increase the tension applied to the occupant step by step, even if the torque of the motor is rapidly increased to release the seat belt locking in the releasing step (s6), the occupant may feel. It can reduce the discomfort. In the release determination step s5 shown in FIG. 2, the dangerous state condition is not continuously detected for a predetermined time, and the motor control apparatus 100 gradually increases the amount of motor supply current to the first threshold current which is its threshold value. In the following, the control state is transferred to the release step s6.

On the contrary, when a dangerous state condition is detected through the periodic monitoring, it is preferable to reduce the amount of motor supply current stepwise to reduce power consumption. In the release determination step (s5 ′) of FIG. 3, the dangerous current condition is not detected at first, and thus the supply current amount is increased. Then, the dangerous condition condition is detected, and the supply current amount is decreased. As a result, the current amount increased to the first threshold current to transition to the release step (s6). In this case, it is preferable to set the threshold (second threshold current) even when the dangerous state condition is detected in the release determination step s5 and the supply current amount decreases. That is, when the dangerous state condition is continuously detected in the release determination step (s5), the motor supply current amount is decreased by the motor control apparatus 100 to the second threshold current, and this decrease is continued so that the supply current amount is the second threshold current. Immediately after reaching, or after a certain time after reaching, the flow returns to the release waiting step s4.

The increase and decrease of the current in the release determination step (s5) is one of the embodiments, and in the case of the increase, it is increased stepwise at a constant rate of increase (first current unit) in units of a predetermined time (for example, 5 ms), but the maximum is increased. It is assumed that the limit is the first threshold current, and in the case of the reduction, stepwise decreases at a constant rate of decrease (second current unit) in units of a predetermined time (for example, 5 ms), but the minimum limit is the second threshold current. Can be. In addition, as one embodiment, the first threshold current or the first current unit may be determined through an experiment based on the degree to which the tension felt by the seat belt wearer due to the torque of the seat belt motor generated therefrom does not give the wearer a feeling of discomfort. . In addition, the second threshold current or the second current unit may also be determined through experiments based on a current value capable of minimizing torque reduction of the seat belt while reducing power consumption as much as possible. As shown in Fig. 3, it is preferable to set the pulling tension of the seat belt at a line which is set at the same value as the amount of current held in the release waiting step s4 or at least more than that.

As described above, when the dangerous state condition is not detected for more than a predetermined time in the release determination step (s5) and the motor supply current reaches the first threshold current, the control state by the motor control apparatus 100 transitions to the release step (s6). do. In the releasing step (s6), the motor control device 100 sends a current which rises sharply to the seat belt motor 200 to increase the torque momentarily, and accordingly the seat belt locking is released. If a specific dangerous state condition is still detected, it may transition back to the previous step, that is, the release determination step (s5). Since the seat belt locking device is generally pulled in the pulling direction to achieve unlocking, if it is determined that all of the dangerous situations are eliminated in this step, the belt locking device is finally released by rapidly increasing the torque as described above.

After releasing the belt locking in the releasing step (s6), the process immediately proceeds to the clutch releasing step (s7). As shown in FIG. 2, in this step, the motor control apparatus 100 supplies a reverse current to the seat belt motor 200. The motor is momentarily reversed to release the clutch of the seat belt device to stop transmission of power between the motor 200 and the seat belt spool. In this case, it is preferable that the attempt to release the clutch continues periodically in preparation for the failure, and the reverse rotation of the clutch with stronger torque is desirable as the cycle is repeated. For example, the period can be assumed to repeat in seconds of 2 or 3 seconds. When the clutch is released, the control of the seat belt motor according to the dangerous situation is completed and the process is transferred back to the non-operation stage (s1), so that the seat belt device operates as a general seat belt device without power transmission of the motor.

In this way, it is possible to accurately determine the release point of the seat belt locking device as the safest point by monitoring the dangerous state condition of the vehicle periodically or at its entry point to perform the step transition and regression according to the degree of the dangerous state. In addition, the vehicle occupant's safety can be further secured.

The release of the seat belt locking device in the release step and the clutch release in the clutch release step will be in accordance with the known art and are not related to the features of the present invention, so a detailed description of its operation principle will be omitted. In addition, the hazard conditions at each stage may be different and some may be the same. Other content described in the detailed description of the invention is only an embodiment of the invention and the scope of the present invention will be determined based on the content described in the claims.

100: motor control device 200: seat belt motor
300: in-vehicle sensor

Claims (5)

In a method of controlling a motor of a motorized seat belt, comprising an electric motor capable of driving the belt spool at least in the pulling direction of the belt webbing, and a seat belt locking device for suppressing the belt spool rotation in the belt webbing pull-out direction. ,
A dangerous operation step of monitoring a state of the vehicle to immediately increase the amount of supply current of the electric motor to draw in the belt and generate tension of the belt when a dangerous state is detected;
An operation maintaining step of maintaining a supply current amount at a constant level when the dangerous operation step is completed and the dangerous state is continued;
A release waiting step of waiting for a predetermined time to release the belt tension when the dangerous state begins to be released in the operation maintaining step, and returning to the operation maintaining step when the dangerous state is maintained or reoccurs;
A release determination step of increasing the supply current of the motor step by step when the waiting state is over and the dangerous state is not found in the release waiting step, and decreasing the supply current of the electric motor step by step when the dangerous state is found; And
If it is determined that the dangerous state has been eliminated in the release determination step, immediately release the belt locking by increasing the supply current of the electric motor, and immediately after the release, reducing the supply current again to release the tension of the belt. Method for controlling the motor of the motorized seat belt, characterized in that. The method of claim 1, wherein the detection of a dangerous state comprises an X acceleration sensor, a Y acceleration sensor, a yaw rate sensor, a wheel speed sensor, a steering angle sensor, a brake pressure sensor, a buckle sensor, a roll- A method for controlling a motor of a motorized seat belt, comprising at least one of a roll-over sensor, a collision sensor, a lane departure sensor, a front radar, and a rear radar. According to claim 1, wherein the motor seat belt includes a clutch for transmitting or disconnecting the rotational force of the electric motor to the belt spool,
The method of controlling the motor of the motorized seat belt further includes a clutch release step of releasing the clutch by reversely rotating the electric motor when all the tension of the belt is released in the release step. How to control. 4. The motorized seat belt according to claim 3, wherein in the clutch release step, the release of the clutch periodically attempts to release the clutch until its success, the periodic attempt to reverse the rotation by gradually applying a stronger force. How to control the motor. The method of claim 1, wherein the increase of the motor supply current in the release determination step is increased in steps of a first current unit up to a first threshold current, and the decrease of the motor supply current is in steps of a second current unit up to a second threshold current. A method for controlling a motor of a motorized seat belt, characterized in that for reducing.

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