JP2007106180A - Electric steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stop certainly an electric motor to perform attitude adjustment of a steering device by sensing a failure in the motor rotating direction using a simple constitution. <P>SOLUTION: The electric steering device is equipped with a steering mechanism where a steering wheel is installed at the tail, an attitude adjusting mechanism having the electric motor for adjusting the position of at least either of the inclining position and the expanding/contracting position of the steering mechanism, motor driving circuits 90A and 90B to control the operation of the motor, and a control part 100 to emit to the motor driving circuits a command value for the rotating direction and the speed for performing the attitude adjustment of the attitude adjusting mechanism. The control part 100 has a motor rotating direction sensing part to sense the rotating direction of the motor and stops the motor driving circuits upon judging that a failure exists in the circuits when the motor rotating direction sensed by the motor rotating direction sensing part is out of agreement with the rotating direction command given to the motor driving circuits. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electric steering apparatus that adjusts the position of at least one of a tilting position and an expansion / contraction position of a steering mechanism.

As this type of electric steering device, the applicant first electrically adjusts the upper column member of the steering column by means of electric and tilt actuators, and the electric tilt actuator is driven by the electric motor and the electric motor. A rod device and a position detection device for detecting the amount of rotation of the electric motor, and an actuator rod extending from the telescopic rod device expands and contracts according to the rotation of the electric motor, and the amount of expansion and contraction at this time is detected by the position detection device. An electric steering column apparatus that digitally detects the number of revolutions has been proposed (see, for example, Patent Document 1).
Japanese Unexamined Patent Publication No. 2000-238647 (first page, FIGS. 1 and 3)

However, in the conventional example described in Patent Document 1, the rotation speed of the electric motor can be detected, but the rotation direction of the motor cannot be detected, and the electric motor is opposite to the command rotation direction. There is a problem that a rotation abnormality that rotates in the direction cannot be detected. In order to solve this problem, an encoder or resolver may be provided separately to detect the rotation direction of the electric motor, as in a general electric motor. In this case, however, the number of parts increases. There is an unsolved problem that the configuration of the electric steering device becomes complicated.
Accordingly, the present invention has been made paying attention to the unsolved problems of the above-described conventional example, and an object thereof is to provide an electric steering device capable of detecting an abnormal rotation of an electric motor with a simple configuration. Yes.

  In order to achieve the above object, an electric steering apparatus according to a first aspect of the present invention includes a steering mechanism having a steering wheel mounted on a rear end side thereof, and an electric motor that adjusts at least one of a tilting position and an expansion / contraction position of the steering mechanism. A posture adjustment mechanism having a motor, a motor drive circuit that drives and controls the electric motor, and a control unit that outputs a command value that commands a rotation direction and a speed for performing posture adjustment of the posture adjustment mechanism to the motor drive circuit. The control unit has a motor rotation direction detection unit that detects a rotation direction of the electric motor, and the motor rotation direction detected by the motor rotation direction detection unit and the motor When the rotational direction command for the drive circuit does not match, it is determined that the motor drive circuit is abnormal and the motor drive circuit is stopped. It is characterized by comprising an abnormal stop.

  According to a second aspect of the present invention, there is provided the electric steering apparatus according to the first aspect of the invention, wherein the electric motor is a brushless motor, and the motor rotation direction detection unit detects a rotor position of the brushless motor. A signal conversion unit that individually converts two motor position detection signals selected from the motor position detection signals output from the element into binary signals, and rises of the two binary signals output from the signal conversion unit; The motor rotation direction is detected on the basis of any one of the falling orders.

According to the present invention, the motor rotation direction detection unit that detects the rotation direction of the front electric motor is provided, and the motor rotation direction detected by the motor rotation direction detection unit and the rotation direction command for the motor drive circuit do not match. Therefore, it is determined that the motor rotation direction is abnormal, and the motor drive circuit is stopped. Therefore, it is possible to accurately detect an abnormality in which the electric motor rotates in the direction opposite to the command direction and to stop driving. .
At this time, as the motor rotation direction detection unit, at least two output signals of the position detection element for detecting the rotor position of the brushless motor are selected and binarized, thereby either rising or falling thereof. Therefore, the rotation direction can be easily detected, and there is no need to provide a separate rotation direction detection means.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an electric steering apparatus showing an embodiment of the present invention. The electric steering apparatus 1 employs a so-called swing tilt method, and holds a steering shaft 3 extending from a steering wheel 2 and connected to a steering gear (not shown) so as to be rotatable around the axis. Three steering columns, that is, an upper column 4, a middle column 5, and a lower column 6 are provided. Then, by appropriately adjusting the relative positions of the columns 4, 5, and 6, the steering shaft 3, and thus the steering wheel 2, is held at a desired position.

  The upper column 4 accommodates a universal joint (not shown) of the steering shaft 3 in the internal space. The upper column 4 is attached to a fork 51 formed at the rear end of the middle column 5 via a tilt hinge pin 51a so as to be tiltable. That is, the tilt position of the steering wheel 2 can be adjusted by appropriately swinging the upper column 4 with the tilt hinge pin 51a as a fulcrum.

  The middle column 5 is fitted and held in the lower column 6 and is slidable in the axial direction together with the fork 51 that supports the upper column 4. That is, by appropriately moving the middle column 5 forward and backward with respect to the lower column 6 fixed to the vehicle body side, the upper column 4 moves in the axial direction together with the steering shaft 3, and the telescopic position of the steering wheel 2 can be adjusted. .

The tilt position of the upper column 4 is adjusted by the electric tilt mechanism 7. The electric tilt mechanism 7 includes, for example, a three-phase brushless motor 71 provided with a gear box 70, a telescopic rod device 72 driven by the brushless motor 71, and a position detection that detects the rotational position of the rotor of the brushless motor 71. Device 73.
The actuator rod 72 a extending from the telescopic rod device 72 expands and contracts according to the rotation of the brushless motor 71, and the amount of expansion and contraction at this time is digitally detected by the position detection device 73 as the rotational speed of the brushless motor 71.

  A front end portion of the telescopic rod device 72 is pivotally attached to a bracket 52 fixed to the middle column 5 with a pin 53, and constitutes a hinge. The rear end portion of the actuator rod 72a is pivotally attached to the bracket 42 fixed to the upper column 4 with a pin 43, and constitutes a hinge. Therefore, if the actuator rod 72a is gradually extended from the telescopic rod device 72, the upper column 4 rotates smoothly counterclockwise with respect to the middle column 5, and the steering wheel 2 can be gradually tilted upward. . On the other hand, if the actuator rod 72a is gradually housed in the telescopic rod device 72, the upper column 4 rotates smoothly in the clockwise direction with respect to the middle column 5, and the steering wheel 2 can be gradually tilted downward. it can. The tilt angle (tilt position) at this time can be converted from the output of the position detection device 73.

  The telescopic position of the upper column 4 is adjusted by an electric telescopic mechanism 8 having substantially the same structure as that of the electric tilt actuator 7. That is, the electric telescopic mechanism 8 includes, for example, a three-phase brushless motor 81 provided with a gear box 80, a telescopic rod device 82 driven by the brushless motor 81, and a position detection for detecting the rotor position of the brushless motor 81. Device 83.

  The front end portion of the telescopic rod device 82 is pivotally attached to a bracket 62 fixed to the lower column 6 with a pin 63, and constitutes a hinge. The rear end portion of the actuator rod 82a is pivotally attached to a bracket 55 fixed to the fork portion 51 of the middle column 5 with a pin 56, thereby constituting a hinge. Therefore, when the actuator rod 82a is extended from the telescopic rod device 82, the middle column 5 is extended from the lower column 6, and the steering wheel 2 can be moved backward. On the other hand, if the actuator rod 82a is housed in the telescopic rod device 82, the middle column 5 is brought into the lower column 6 and the steering wheel 2 can be moved forward.

The bracket 52 fixed to the middle column 5 is guided by a groove 6 a formed in the lower column 6 and can slide along the middle column 5 along the axial direction with respect to the lower column 6.
Here, the brushless motors 71 and 81 incorporate motor drive circuits 90A and 90B. As shown in FIG. 3, these motor drive circuits 90A and 90B include a signal ST / SP indicating start and stop, a rotation direction signal CW / CCW indicating a rotation direction, and a speed input from the control device 100 described later. The pulse width modulation signal PWM representing the command and the outputs of the position detection elements 91u to 91w, which are hall elements, for example, constituting the position detection devices 73 and 83 for detecting the rotor positions of the brushless motors 71 and 81 are converted into binary signals. A rotational position signal inputted from the Schmitt trigger circuits 92u to 92w is inputted, and based on these, a three-phase distribution circuit 93 that forms a three-phase drive signal for driving the brushless motors 71 and 81, and the three-phase distribution circuit 93 Three-phase drive signal output from the overcurrent detection circuit 94 for detecting an overcurrent of an inverter circuit 96 to be described later. And an over-current detection value signal SI of the field effect transistors Qua to Qwb constituting the inverter circuit 96, and a pair of field effect transistors (FETs) Qua, Qub, Qva, Qvb, Qwa, and Qwb are connected in series, and an inverter circuit 96 is provided in which three sets of FET circuits corresponding to the phase coils Lu, Lv, and Lw of the brushless motors 71 and 81 are connected in parallel. Here, the FET gate drive circuit 95 is input from the three-phase distribution circuit 93 when an overcurrent detection signal SI of, for example, a logical value “0” representing a normal motor current state is input from the overcurrent detection circuit 94. The pulse width modulation signal PWM is supplied to the gates of the field effect transistors Qua to Qwb of the inverter circuit 96 so as to drive the rotation direction and rotation speed brushless motors 71 and 81 according to the three-phase drive signal. For example, when an overcurrent detection signal SI having a logical value “1” representing an overcurrent state is input from 94, for example, PWM is supplied to the gates of the field effect transistors Qub, Qvb and Qwb constituting the lower arm of the inverter circuit 96 The duty ratio of the signal is controlled to 0% to stop energization to the excitation coils Lu to Lw of the brushless motor 71 or 81. Make.

  The motor drive circuits 90A and 90B are driven and controlled by the control device 100. As shown in FIG. 2, the control device 100 includes a regulator 103 to which a battery voltage Vb from a battery 101 mounted on a vehicle is input via a fuse 102, and a vehicle speed sensor as a running state detection unit mounted on the vehicle. A communication interface 105 that acquires the vehicle speed detection value 104 from another control system via a communication line, an arithmetic processing unit (CPU) 106 that is operated by a power supply voltage Vc output from the regulator 103, and the arithmetic processing unit 106 And a relay circuit 108 as a switching unit interposed in the control device 100 between the fuse 102 and the battery voltage input terminals of the motor drive circuits 90A and 90B. .

The arithmetic processing unit 105 is directly input with the battery voltage V _B , the power supply voltage of the regulator 103, and an ignition signal IG output from the ignition switch 111 connected to the battery 101 via the fuse 110. The key switch signal KS output from the key switch 113 connected to the battery 101 via the fuse 112, the door signal DS of the door switch 114 indicating the opening / closing state of the passenger door, and the inclination angle of the tilt mechanism 7 Switch signals ST1 and ST2 of the telescopic switch unit 116 for instructing the expansion / contraction position of the manual tilt switch unit 115 and the telescopic mechanism 8, and a position detection signal FG1 having a phase difference of 120 degrees output from the motor drive circuits 90A and 90B, and FG2 is input That.

The arithmetic processing unit 106 executes motor control processing when the control power source Vc is input from the regulator 103.
The motor control process, the control voltage Vc from the regulator 103 is started running when the supply has been started, first, at step S1, turns on the switching element 120 connected between ground and the relay coil L _LR of relay circuit 108 After a high level relay control signal SL for controlling the state is output to the switching element 120, the process proceeds to step S2.

  In step S2, it is determined whether or not the motor drive circuits 90A and 90B are abnormal. When the motor drive circuits 90A and 90B are abnormal, the process proceeds to step S3, and the low level relay control signal SL is switched to the switching element. Then, the process is terminated after the switching element 120 is controlled to be in the OFF state. When the motor drive circuits 90A and 90B are normal, the process proceeds to step S4.

  In this step S4, the motor drive circuit 90A of the tilt mechanism 7 is operated to drive the tilt mechanism 7 in the direction of the top dead center contacting the upper mechanical stopper (not shown) to detect contact with the mechanical stopper. When the control origin is set, the control origin is set to move to the control origin that is the top dead center of the electric tilt control range returned from the position by a predetermined amount. Then, the process proceeds to step S5.

  In this step S5, the motor drive circuit 90B of the telescopic mechanism 8 is operated to drive the telescopic mechanism 8 in the direction of the bottom dead center contacting the contraction side mechanical stopper (not shown) to contact the mechanical stopper. When it is detected, a control origin setting process for moving to the control origin which is the bottom dead center of the electric telescopic control range returned from the position to the predetermined amount extension side is performed, and then the process proceeds to step S6.

  In this step S6, the ignition signal IG is read, and then the process proceeds to step S7, where it is determined whether or not the ignition signal IG is on when the engine is started, and the ignition switch 111 is off when not starting the engine. In some cases, the process proceeds to step S8, and the low level relay control signal SL is output to the switching element 120, and then the process returns to step S6. When the engine is started and the ignition switch 111 is on, the process proceeds to step S9. After shifting to outputting the high level relay control signal SL to the switching element 120, the process proceeds to step S10.

  In this step S10, the engine start frequency N is incremented by “1”, and then the process proceeds to step S11, where it is determined whether or not the engine start frequency N has reached a preset set value Ns, and N ≧ Ns. In some cases, the engine start start number N reaches the set value Ns and it is determined that the control origin correction is necessary, the process proceeds to step S12, the engine start number N is reset to “0”, and then the process returns to step S4. When N <Ns, it is determined that the control origin correction is not necessary yet, and the process proceeds to step S13.

In this step S13, it is determined whether or not the tilt position is stored in the tilt position storage area of the storage device 107. If the tilt position is not stored, the process proceeds to step S14, and the tilt mechanism 7 is set in the manual operation range. After moving down to the top dead center position, the process proceeds to step S16.
On the other hand, when the determination result of step S13 is that the tilt position is stored, the process proceeds to step S15, the tilt mechanism 7 is lowered to the stored tilt position, and then the process proceeds to step S16.

  In this step S16, it is determined whether or not the telescopic position is stored in the telescopic position storage area of the storage device 107. When the telescopic position is stored, the process proceeds to step S17, and the telescopic mechanism reaches the stored telescopic position. 8 is extended to step S18, and if the telescopic position is not stored, the process directly goes to step S18.

  In step S18, it is determined whether or not a switch signal ST1 for designating a tilt position is input from the manual tilt switch unit 115. When the switch signal ST1 is input, the process proceeds to step S19 to input the input switch signal ST1. After the tilt mechanism 7 is controlled to the tilt position corresponding to the above, the process proceeds to step S20, and when the switch signal ST1 is not input, the process proceeds directly to step S20.

  In step S20, it is determined whether or not a switch signal ST2 for designating a telescopic position is input from the manual telescopic switch unit 116. When the switch signal ST2 is input, the process proceeds to step S21, and the input switch signal is input. After the telescopic mechanism 8 is controlled to the telescopic position corresponding to ST2, the process proceeds to step S22. When the switch signal ST2 is not input, the process directly proceeds to step S22.

  In this step S22, it is determined whether or not a predetermined time T1 has elapsed since the previous switch signal ST1 or ST2 was input. When the predetermined time T1 has elapsed, the process proceeds to step S27 described later, and the predetermined time T1 has elapsed. If not, the process proceeds to step S23, the vehicle speed detection value Vs detected by the vehicle speed sensor 104 is read, and then the process proceeds to step S24, where the vehicle speed detection value Vs is a threshold Vst at which it can be determined that the vehicle is running. If Vs ≧ Vst, the process proceeds to step S27, which will be described later. If Vs <Vst, it is determined that the vehicle is stopped and the process proceeds to step S25.

In this step S25, it is determined whether or not the abnormality determination flag FA is set to “1” indicating an abnormality. When FA = “1”, that is, when an abnormal state occurs, the process proceeds to step S26. The low level relay control signal SL for turning off the relay circuit 108 is output to the switching element 120 interposed between the relay coil L _L and the ground, and the switching element 120 is controlled to be in the off state. To end the motor control process.

On the other hand, when the determination result in step S25 is FA = “0”, that is, in a normal state where no abnormal state has occurred, the process returns to step S18.
In step S27, a low-level relay control signal SL for turning off the relay circuit 108 is output to the switching element 120 interposed between the relay coil _LLR and the ground in the same manner as in step S26. After the element 120 is controlled to be turned off, the process proceeds to step S28.

  In this step S28, the key switch signal KS output from the key switch 113 is read, and then the process proceeds to step S29 to determine whether or not the key switch signal KS is in an off state, that is, whether the driver is likely to do the latter. When the key switch signal KS continues to be on, the driver determines that the possibility of the latter is almost impossible and waits until the key switch signal KS is turned off. When it is turned off, the process proceeds to step S30.

In this step S30, it is determined whether or not an abnormality determination flag FA is set to “1” in an abnormality detection process to be described later. When this flag is set to “1”, the motor control process is terminated as it is, and an abnormality determination is made. When the flag FA is reset to “0”, the process proceeds to step S31.
In step S31, similar to step S1 described above, a high level relay control signal SL for controlling the switching element 120 connected between the relay coil _LLR of the relay circuit 108 and the ground to the ON state is supplied to the switching element 120. After output, the process proceeds to step S32.

In this step S32, it is determined whether or not the current tilt position matches the tilt position stored in the tilt position storage area of the storage device 107. If they do not match, the process proceeds to step S33, where After the tilt position is updated and stored in the tilt position storage area, the process proceeds to step S34, and when both coincide, the process proceeds directly to step S34.
In this step S34, it is determined whether or not the current telescopic position matches the telescopic position stored in the telescopic position storage area of the storage device 107. If they do not match, the process proceeds to step S35. After the current telescopic position is updated and stored in the telescopic position storage area of the storage device 107, the process proceeds to step S36. If the two coincide, the process proceeds to step S36.

In step S36, the movement to the upper retracted position in the case of automatically controlling the tilt mechanism 7 is performed, and then the process proceeds to step S37. The telescopic mechanism 8 is moved to the retracted retracted position, and then the process returns to step S6.
Further, the arithmetic processing unit 106 executes the abnormality detection process shown in FIG. 5 as a timer interrupt process for every predetermined time (for example, 10 msec). In this abnormality detection process, first, in step S41, the motor position detection signals FG1 and FG2 output from the motor drive circuit 90A are read, and then the process proceeds to step S42, where the speed command value PWM for the motor drive circuit 90A is “0”. When the speed command value PWM is “0”, the process proceeds to step S43, and at least one of the motor position detection signals FG1 and FG2 output from the motor drive circuit 90A has a state change. When the state change occurs, the speed command value PWM is “0”, and the brushless motor 71 is driven to rotate even though the motor drive circuit 90A is not driven. It is determined that an abnormality such as a power fault has occurred in the circuit 90A, the process proceeds to step S44, and the abnormality determination flag FA is set to “1”. Set, when the no state change proceeds to step S49 where the motor drive circuit 90A will be described later it is judged that it is normal.

  On the other hand, when the determination result of step S42 is that the speed command value PWM is other than “0”, the process proceeds to step S45, where it is determined whether or not the motor position detection signals FG1 and FG2 have changed their state within a predetermined time. When these are not changed, it is determined that the brushless motor 71 is not rotating abnormally and the process proceeds to step S44. When the motor position detection signals FG1 and FG2 are changed, the brushless is temporarily stopped. It is determined that the motor 71 is normal, and the process proceeds to step S46.

  In this step S46, the rotation direction command CW / CCW for the motor drive circuit 90A is read, and then, in step S47, the motor position detection signals FG1 and FG2 input from the motor drive circuit 90A are read, and both signals FG1 and FG2 are read. The direction of rotation is detected from the order of the rising edges. That is, for example, when the brushless motor 71 is rotating forward, the position detection signals FG1 and FG2 are advanced in phase by 120 degrees in electrical angle with respect to the position detection signal FG1, as shown in FIG. On the contrary, when the brushless motor 71 is reversely rotated, as shown in FIG. 7, the position detection signal FG2 is in a phase delay state where the electrical angle is delayed by 120 degrees with respect to the position detection signal FG1. For this reason, when the rise time of the position detection signal FG1 comes from the rise time to the fall time of the position detection signal FG2, it is determined as the forward rotation direction, and conversely, from the rise time to the fall time of the position detection signal FG1. When the rising edge of the position detection signal FG2 comes, the reverse direction can be determined.

  Next, the process proceeds to step S48, where it is determined whether or not the rotation direction command CW / CCW matches the rotation direction detection value detected in step S47. If they do not match, the motor drive circuit 90A is abnormal. The process proceeds to step S44, and if they match, it is determined that the motor drive circuit 90A is normal and the process proceeds to step S49.

  In step S49, the motor position detection signals FG1 and FG2 output from the motor drive circuit 90B are read, and then the process proceeds to step S50 to determine whether or not the speed command value PWM for the motor drive circuit 90B is “0”. When the speed command value PWM is “0”, the process proceeds to step S51 to determine whether or not a state change has occurred in at least one of the motor position detection signals FG1 and FG2 output from the motor drive circuit 90B. When the state change occurs, the speed command value PWM is “0”, and the brushless motor 81 is rotationally driven even though the motor drive circuit 90B is not driven. It is determined that an abnormality has occurred, the process proceeds to step S52, the abnormality determination flag FA is set to “1”, and the state changes If it does not occur, it is determined that the motor drive circuit 90B is normal, and the process proceeds to step S57. After the abnormality determination flag FA is reset to “0”, the timer interrupt process is terminated and the program returns to the predetermined main program. .

  On the other hand, when the determination result in step S50 is that the speed command value PWM is other than “0”, the process proceeds to step S53, where it is determined whether or not the motor position detection signals FG1 and FG2 have changed their state within a predetermined time. When these are not changed, it is determined that the brushless motor 81 is in an abnormal state where it is not rotating, and the process proceeds to step S52. When the motor position detection signals FG1 and FG2 are changed, the brushless is temporarily changed. It is determined that the motor 81 is normal, and the process proceeds to step S54.

In this step S54, the rotational direction command CW / CCW for the motor drive circuit 90B is read, and then the process proceeds to step S55, and the motor position detection signals FG1 and FG2 input from the motor drive circuit 90B as in the above-described step S47. The rotation direction of the motor is detected from the reading order of both signals FG1 and FG2.
Next, the process proceeds to step S56, where it is determined whether or not the rotation direction command CW / CCW matches the rotation direction detection value detected in step S55. If the two do not match, the motor drive circuit 90B is abnormal. The process proceeds to step S52, and if they match, it is determined that the motor drive circuit 90B is normal and the process proceeds to step S57.

  4 and 5, the processes of S1, S4 to S22, and S25 to S35 in the process of FIG. 4 correspond to the control unit, and the processes of steps S46, S47, S54, and S55 in the process of FIG. Corresponding to the rotation direction detection unit, the processing of steps S44, S48, S52 and S55 and the processing of steps S2, S3, S23 and S24 of FIG. 4 correspond to the abnormal stop unit.

Next, the operation of the above embodiment will be described.
Now, when the tilt mechanism 7 and the telescopic mechanism 8 are assembled in the vehicle at the production factory, and the battery 101 is mounted, and the battery voltage V _B is input from the battery 101 to the control device 100, the control voltage Vc is supplied from the regulator 103. Is supplied to the arithmetic processing device 106, the motor processing processing of FIG. 4 and the abnormality detection processing of FIG.

At this time, it is assumed that no abnormality has occurred in the motor drive circuits 90A and 90B, and the abnormality determination flag FA has been reset to “0” in the abnormality detection processing of FIG.
Therefore, the motor control process shown in FIG. 4, at step S1, by outputting a relay control signal SL of high level to the switching element 120, to the relay contacts t _LR turned on by energizing the relay coil L _LR Thus, supply of the battery voltage V _B to the motor drive circuits 90A and 90B of the brushless motors 71 and 81 is started.

Since the abnormality determination flag FA has been reset to “0”, the process proceeds from step S2 to step S4 to perform control origin setting processing for setting the control origin of the tilt mechanism 7, and then the process proceeds to step S5. A control origin setting process for setting the control origin of the telescopic mechanism 8 is performed.
For this reason, in the tilt mechanism 7, the steering shaft 3 becomes the upper dead center position on the upper side, and the steering wheel 2 is retracted upward. Further, in the telescopic mechanism 8, the middle column 5 contracts with respect to the lower column 6. In this state, the steering wheel 2 is retracted upward and forward so that the driver can easily get on and off.

At this time, if the ignition switch 111 is in an off state, the process proceeds from step S6 to step S7 through step S8, and the switching element 120 is turned off by outputting a low-level relay control signal SL to the switching element 120. In this state, the relay circuit 108 is turned off, supply of the battery voltage V _B to the motor drive circuits 90A and 90B of the brushless motors 71 and 81 is stopped, and a loop processing state is repeated in which steps S6 to S8 are repeated.

Thereafter, when the vehicle is shipped from the factory or the user is in a state of using the vehicle and the driver gets on and starts the engine with the ignition switch 111 turned on, the process of FIG. 4 changes from step S7 to step S9. Then, the relay control signal SL is output to the switching element 120, and the relay circuit 108 is controlled to be turned on, so that the battery voltage V _B is applied to the motor drive circuits 90A and 90B of the brushless motors 71 and 81. Supplied and ready for operation.

  At this time, the engine start count N is incremented, and when the engine start count N has not reached the set value Ns, the routine proceeds from step S11 to step S13, and the tilt position of the tilt mechanism 7 is first stored in the tilt position of the storage device 107. It is determined whether or not it is stored in the area. When the vehicle has just been delivered to the user, since the tilt position and the telescopic position storage area of the storage device 107 are not stored in the tilt position storage area and the telescopic position storage area, the process proceeds from step S13 to step S14. The brushless motor 71 of the tilt mechanism 7 is driven, for example, a reverse rotation direction command CCW and a tilt position command PWM of a predetermined number of pulses are output to rotate the brushless motor 71 to move the steering shaft 3 of the tilt mechanism 7 within the manual operation range. Lower to the highest point. As a result, the steering wheel 2 is lowered within the operable range of the driver.

On the other hand, the telescopic mechanism 8 is originally set to the most contracted side of the contraction range of the middle column 5 since the telescopic mechanism 8 is jumped from step S16 to step S18. maintain.
Thereafter, when the driver wants to adjust the tilt position, the user selects a desired tilt position with the manual tilt switch section ST1, and when a switch signal ST1 corresponding to the selected tilt position is input, according to the input switch signal ST1. For example, a reverse direction command CCW and a speed command PWM are output to the motor drive circuit 90A, the brushless motor 71 is reversely rotated, for example, and the steering wheel 2 is lowered to a driver's desired tilt position.

  Similarly, when the operator adjusts the telescopic position, the user selects the desired telescopic position by operating the manual telescopic switch unit 116, and when the switch signal ST2 corresponding thereto is input, the input switch In response to the signal ST2, for example, a reverse direction command CCW and a speed command PWM are output to the motor drive circuit 90B, the brushless motor 81 is reversely rotated, for example, and the steering wheel 2 is extended to the driver's desired telescopic position.

Thus, the driver can move the steering wheel 2 to a position desired by the driver by operating the manual tilt switch unit 115 and the manual telescopic switch unit 116.
Thereafter, until the predetermined time elapses after the driver operates the manual tilt switch unit 115 or the manual telescopic switch unit 116 last operated, the position selection operation in the manual tilt switch unit 115 and the manual telescopic switch unit 116 is performed. However, when a predetermined time has elapsed or when the vehicle speed detection value Vs detected by the vehicle speed sensor 104 is equal to or greater than the threshold value Vst and it is determined that the vehicle is in a traveling state, the process proceeds from step S22 or step S24 to step S27. By outputting the low-level relay control signal SL to the switching element 120, the relay circuit 108 is controlled to be in the OFF state, the supply of the battery voltage V _B to the motor drive circuits 90A and 90B is stopped, and the brushless motor 71 And 81 are stopped, and the tilt machine Actuation of 7 and telescopic mechanism 8 is stopped.

As described above, when the predetermined time has elapsed without the manual tilt switch 115 and the manual telescopic switch unit 116 being operated, or when the vehicle speed detection value Vs is equal to or greater than the threshold value Vst and the vehicle is in the running state, the driver's tilt position and Since it is determined that the adjustment of the telescopic position has been completed, the relay circuit 108 is turned off, and the supply of the battery voltage V _B to the motor drive circuits 90A and 90B is stopped. Thereafter, the tilt mechanism 7 and the telescopic mechanism 8 Inadvertent operation can be reliably prevented.

Thereafter, if the key switch 113 is turned off before the driver gets out of the vehicle, the process proceeds from step S29 to step S30 in the process of FIG. 4, and when the abnormality determination flag FA is reset to “0”, the process proceeds to step S30. In S31, the relay circuit 108 is controlled to be turned on by outputting a high level relay control signal SL to the switching element 120, and supply of the battery voltage V _B to the motor drive circuits 90A and 90B is started. Then, the tilt mechanism 7 and the telescopic mechanism 8 are brought into an operable state.

Next, it is determined whether or not the current tilt position matches the tilt position stored in the tilt position storage area of the storage device 107. Since the tilt position is not stored, the current tilt position is stored in the tilt position storage area. (Step S33).
Similarly, it is determined whether or not the current telescopic position matches the telescopic position stored in the telescopic position storage area of the storage device 107, and since the telescopic position is not stored, the current telescopic position is stored in the telescopic position storage. It is stored in the area (step S35).

  Next, the speed command PWM and, for example, the forward rotation command CW are output to the motor drive circuit 90A of the tilt mechanism 7, the brushless motor 71 is rotated forward, and the steering wheel 2 is moved to the retreat position where the top dead center is located. Then, the speed command PWM and, for example, the forward rotation command CW are output to the motor drive circuit 90B of the telescopic mechanism 8, the brushless motor 81 is rotated forward, the middle column 5 is contracted, and the steering wheel 2 is moved to the vehicle. It is retracted to the front side and a moving space is formed in the front part of the driver, so that the driver can easily get on and off.

  Thus, when the tilt position and the telescopic position are stored in the tilt position storage area and the telescopic position storage area of the storage device 107, each time the driver gets on and turns on the ignition switch 111, The brushless motor 71 of the tilt mechanism 7 and the brushless motor 81 of the telescopic mechanism 8 are automatically controlled so that the tilt position and the telescopic position stored in the tilt position storage area and the telescopic position storage area of the storage device 107 are obtained.

  However, in the abnormality detection process of FIG. 5 executed by the arithmetic processing unit 106, the motor drive circuit 90A is in a state where the speed command PWM for the motor drive circuit 90A is “0”, that is, the brushless motor 71 is not driven. When any of the input motor position detection signals FG1 and FG2 changes state, a short circuit occurs in the field effect transistors Qub to Qwb constituting the lower arm of the motor drive circuit 90A, or a ground fault occurs in the brushless motor 71. For example, the abnormality determination flag FA is set to “1” (step S44).

  In addition, when the speed command value PWM exceeding “0” is output to the motor drive circuit 90A and the brushless motor 71 is rotationally driven, a disconnection occurs between the control device 100 and the brushless motor 71, and the brushless motor 71 is driven. Is not rotated, or the field effect transistors Qub to Qwb constituting the lower arm are controlled to be turned off by the FET gate drive circuit 95 that has detected the overcurrent by the overcurrent detection circuit 94, and the rotation of the brushless motor 71 is stopped. When an abnormality occurs due to a state of being set to an abnormal state, the abnormality determination flag FA is set to “1”.

  Further, the order of the rotation direction command CW / CCW for the motor drive circuit 90A and the rising point of the motor position detection signals FG1 and FG2 input from the motor drive circuit 90A, that is, which phase of the motor position detection signals FG1 and FG2 is advanced. Is detected to detect the rotation direction of the motor (step S47). Even when the detected rotation direction value and the rotation direction command CW / CCW do not match, it is determined that the motor drive circuit 90A is abnormal and the abnormality determination flag FA is set. Set to “1”.

  As described above, the position detection elements 91u to 91w configured by, for example, Hall elements that detect the rotor position of the brushless motor 71 are converted into binary signals by the Schmitt trigger circuits 92u to 92w. By selecting two signals and supplying them as the motor position signals FG1 and FG2 to the control device 100, the abnormality detection processing of the control device 100 detects which phase of the motor position signals FG1 and FG2 is advanced. Thus, the rotation direction of the motor can be accurately detected. In addition, since the position detection elements 91u to 91w originally provided in the brushless motor 71 are used as the motor rotation direction detection unit, there is no need to separately provide a motor rotation direction detection means such as an encoder or resolver, and the number of parts can be reduced. The entire configuration can be simplified and the cost can be reduced.

Further, the same abnormality detection as described above is performed for the motor drive circuit 90B of the telescopic mechanism 8.
When an abnormality occurs in either of the motor drive circuits 90A and 90B and the abnormality determination flag FA is set to “1”, the arithmetic processing unit 106 is turned on in the motor control process of FIG. In the initial state, when the abnormality determination flag FA is set to “1”, the process proceeds from step S2 to step S3, and the relay control signal SL of a low level is output to the switching element 120, so that the relay is immediately performed. The circuit 108 is controlled to be in an off state, and the motor control process is terminated. For this reason, since the battery voltage V _B supplied to the motor drive circuits 90A and 90B is reliably cut off, it is possible to reliably prevent the brushless motors 71 and 81 from being driven when an abnormality occurs.

In the above embodiment, the case where the motor drive circuits 90A and 90B are incorporated in the brushless motors 71 and 81 has been described. However, the present invention is not limited to this, and the motor drive circuits 90A and 90B are included in the control device 100. The present invention can be applied even when it is provided inside.
In the above embodiment, the case where the waiting loop process is performed in steps S6 to S8 in the motor control process of FIG. 4 while the ignition switch 111 is kept in the OFF state has been described. However, the present invention is not limited to this. Instead, when the tilt mechanism 7 and the telescopic mechanism 8 are moved to the retracted position at the end of the previous run, the process proceeds to a standby process in which only the state change of the ignition switch 111 is monitored, and the ignition switch 111 is turned on. The processing in FIG. 4 may be resumed at that time.

Further, in the above-described embodiment, the case where the regulator 103 of the control device 100 is directly connected to the battery 101 via the fuse 102 has been described. However, the present invention is not limited to this, and the regulator 103 is connected via the key switch 113. The battery voltage V _B may be supplied, and in this case, a non-volatile memory may be applied as the storage device 107 to store the tilt position, telescopic position, engine start frequency N, and the like. .

Furthermore, in the above embodiment, the case where the three-phase brushless motors 71 and 81 are applied has been described. However, the present invention is not limited to this, and a brushless motor having four or more phases can be applied. Can also be applied.
In the above embodiment, the case where the tilt mechanism 7 and the telescopic mechanism 8 are controlled to the stored tilt position and telescopic position when the ignition switch 111 is turned on has been described. However, the present invention is not limited to this. The tilt mechanism 7 and the telescopic mechanism 8 are stored when the door switch 114 changes from the open state to the closed state, that is, when the driver closes the door on the driver's seat side after sitting on the seat. You may make it move to the tilt position and telescopic position.

Moreover, in the said embodiment, although the case where the tilt mechanism 7 and the telescopic mechanism 8 were provided as an attitude | position adjustment mechanism was demonstrated, any one may be abbreviate | omitted.
Furthermore, in the above embodiment, the case where the supply of the battery voltage V _B to the motor drive circuits 90A and 90B is interrupted by one relay circuit 108 has been described, but the present invention is not limited to this, and the motor drive circuit 90A is not limited thereto. In addition, a relay circuit may be provided separately for 90B and 90B so that the supply of the battery voltage V _B is cut off only to the motor drive circuit that has become abnormal.

Furthermore, in the said embodiment, although the Schmitt trigger circuit 92u-92w which converts the position detection signal detected by the position detection elements 91u-91w into a binary signal was provided in motor drive circuit 90A and 90B, it demonstrated. However, the present invention is not limited to this, and a Schmitt trigger circuit may be provided on the control device 100 side. Further, the conversion circuit to the binary signal is not limited to the Schmitt trigger circuit. A comparator that binarizes the sine wave output from the detection elements 91u to 91w by determining whether the sine wave is positive or negative may be applied. In short, the sine wave may be binarized.
Furthermore, although the case where the motor rotation direction is detected by software has been described in the above embodiment, the present invention is not limited to this, and the rotation direction is detected by a hardware circuit configuration that combines a differentiation circuit, a comparison circuit, and the like. You may do it.

It is a schematic structure figure showing one embodiment of the present invention. It is a block diagram which shows the control circuit which can be applied to this invention. FIG. 3 is a block diagram showing a specific configuration of the motor drive circuit of FIG. 2. It is a flowchart which shows an example of the motor control processing procedure performed with the arithmetic processing unit of FIG. It is a flowchart which shows an example of the abnormality detection process procedure performed with the arithmetic processing unit of FIG. It is a wave form diagram which shows the signal waveform of the position detection signals FG1 and FG2 in a state where the brushless motor is rotated forward. It is a wave form diagram which shows the signal waveform of the position detection signals FG1 and FG2 in a state where the brushless motor is reversed.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electric steering device, 2 ... Steering wheel, 3 ... Steering shaft, 4 ... Upper column, 5 ... Middle column, 6 ... Lower column, 7 ... Electric tilt mechanism, 8 ... Electric telescopic mechanism, 71 ... Brushless motor, 81 ... Brushless motor, 90A, 90B ... motor drive circuit, 91u-91w ... position detection element, 92u-92w ... Schmitt trigger circuit, 93 ... three-phase distribution circuit, 94 ... overcurrent detection circuit, 95 ... FET gate drive circuit, 96 ... Inverter circuit, 100 ... control device, 101 ... battery, 103 ... regulator, 104 ... vehicle speed sensor, 106 ... arithmetic processing device, 107 ... storage device, 108 ... relay circuit, 111 ... ignition switch, 113 ... key switch, 114 ... door Switch, 115 ... Manual tilt switch , 116 ... manual telescopic switch unit

Claims (2)

A steering mechanism to which a steering wheel is mounted on the rear end side, an attitude adjustment mechanism having an electric motor that adjusts at least one of a tilting position and an expansion / contraction position of the steering mechanism, and a motor drive circuit that drives and controls the electric motor; An electric steering apparatus comprising: a control unit that outputs a command value for instructing a rotation direction and a speed for performing posture adjustment of the posture adjustment mechanism with respect to the motor drive circuit;
The control unit includes a motor rotation direction detection unit that detects a rotation direction of the electric motor, and the motor rotation direction detected by the motor rotation direction detection unit and a rotation direction command for the motor drive circuit do not match. And an abnormal stop section for determining that the motor drive circuit is abnormal and stopping the motor drive circuit.   The electric motor is a brushless motor, and the motor rotation direction detection unit individually receives two motor position detection signals selected from motor position detection signals output from a position detection element that detects a rotor position of the brushless motor. It has a signal conversion unit that converts it into a binary signal, and is configured to detect the motor rotation direction based on either the rising or falling order of the two binary signals output from the signal conversion unit. The electric steering apparatus according to claim 1, wherein:

Images