JP5487808B2 - Electromagnetic induction type electric vehicle - Google Patents

Description

  The present invention relates to an electromagnetic induction type electric traveling vehicle that performs automatic traveling along a traveling road while detecting a magnetic field generated by a guide wire laid along the traveling road and performing steering control.

  An electromagnetic induction type electric traveling vehicle is used as a vehicle that travels on a predetermined traveling path like a golf cart that travels on a traveling path installed along a golf course. This type of electric traveling vehicle includes a vehicle body including wheels including steering wheels and driving wheels, an electric drive device that drives the driving wheels using a motor as a power source, a braking device that applies braking to the wheels, and a steering motor. Steering device that operates the steering wheel as a drive source, and information on the distance between the guiding line by detecting the magnetic field generated by the guiding line laid along the traveling path from the left and right sides of the guiding line on the vehicle body side. The left and right guidance sensors that output detection signals including the steering wheel and the wheels on the road by controlling the steering motor so that the deviation between the left and right guidance sensor outputs falls within an allowable range. And a controller having steering control means for performing steering control to maintain the position.

  In general, the induction sensor includes a left induction sensor and a right induction sensor that detect a magnetic field generated by the induction line on the left side and the right side of the induction line and output a detection signal including information on the distance to the induction line. Used. The steering control means controls the steering motor so as to keep the deviation of the outputs of these guidance sensors below a set value (preferably to minimize), so as to keep the wheels positioned on the road. Steering control for controlling the direction of the steering wheel is performed, and the vehicle body is traveled along the traveling path while maintaining a state in which the guide line is always positioned at the center between the left and right guidance sensors. This type of electric traveling vehicle is disclosed in Patent Document 1, for example.

  In this specification, the “traveling road” is a portion that extends in the traveling direction of the electric traveling vehicle and travels when the electric traveling vehicle automatically travels. The travel path is formed of concrete or asphalt, but the form is arbitrary. The traveling road may be formed in a strip shape having a width necessary for traveling the electric traveling vehicle. As shown in Patent Document 2, the left and right wheels of the electric traveling vehicle are individually provided. There may be a case where a plurality of portions (orbits) extending in parallel with the traveling direction have a width dimension necessary for holding. Further, the travel path may be a belt-like region set in a part (for example, an end) of the road having a width dimension necessary for traveling the electric traveling vehicle. In any case, a guide wire extending along the longitudinal direction is laid on the travel path. The guide wire is usually laid so as to be positioned at the center in the width direction of the body of the electric vehicle traveling on the road, and in order to generate an alternating magnetic field detected by the induction sensor, An alternating current having a predetermined frequency is energized.

  In the electric vehicle that performs the steering control as described above, when the distance between the left guide sensor and the guide line becomes longer than the distance between the right guide sensor and the guide line, the left guide sensor is connected to the guide line. When the distance between the left guidance sensor and the guide line is shorter than the distance between the right guide sensor and the guide line, move the left guide sensor away from the guide line. By controlling the steering device so as to displace the steering wheel, the steering control is performed so as to maintain the state where the guide line is always located at substantially the center between the left and right guidance sensors.

  Such control can be performed normally if the left and right guidance sensors are positioned on the left and right sides of the guide line, respectively. When the sensor is located on the same side, control is performed in such a way that the guidance sensor located near the guide line is moved away from the guide line. Therefore, both the left and right guide sensors are controlled in the direction away from the guide line. Therefore, steering control cannot be performed correctly. Even when the left and right inductive sensors are located on the left and right sides of the inductive sensor, depending on the set control characteristics, when the deviation of the output of the left and right inductive sensors becomes excessive, the control is not in time, Steering control may not be performed correctly. In this specification, a state in which steering control cannot be performed correctly is referred to as “derailing”.

  An electric vehicle that travels on a roadway has a large deviation from the normal driving direction when an external force is applied to the vehicle body or a wheel slips. It may shift greatly and enter the “derail” state. If such a state is left unattended, the vehicle body may travel in an unexpected direction, which is not preferable. When an electric traveling vehicle derails, it is necessary to stop the vehicle once and return it to a normal state, and then restart the vehicle.

  Patent Document 3 discloses a technique for facilitating an operation when returning an electric vehicle (golf cart) once removed from the travel path due to overtaking or the like onto the travel path. In the invention disclosed in Patent Document 3, the front guidance detector disposed at the front part of the center of the vehicle, and the left guidance detection disposed behind the front guidance detector and disposed on the left side and the right side of the vehicle, respectively. Using a total of four induction detectors consisting of a middle detector and a right induction detector and a middle induction detector located in the center of the vehicle, near the left and right induction detectors, and behind the left and right induction detectors When returning the vehicle off the road to the road, the four guidance detectors determine the direction in which the vehicle travels based on the order in which the magnetic fields generated from the guidance lines are detected, and the vehicle is It is moved forward or backward in the direction to guide it to the road.

JP 2003-5832 A Japanese Utility Model Publication No. 62-103804 JP-A-8-161041

  When an electric vehicle derails, it is desirable to automatically perform the operation of returning the vehicle to a normal state after stopping the vehicle, but in the derailed state, steering control based on the outputs of the left and right guidance sensors Therefore, it is necessary to devise in order to automatically perform the operation of returning the vehicle body to a normal state.

  According to the invention disclosed in Patent Document 3, it is possible to return a derailed vehicle to a normal state. However, in the invention disclosed in the Patent Document, a vehicle deviated from the travel path is guided onto the travel path. Since four inductive sensors are provided in order to make it possible, it is inevitable that the structure becomes complicated and the control becomes complicated and the cost becomes high.

  An object of the present invention is to provide an electromagnetic induction type electric traveling vehicle that can automatically perform an operation of returning a derailed vehicle to a traveling path without using more induction sensors than necessary. It is in.

The invention described in claim 1 of the present application includes a vehicle body including wheels including steering wheels and driving wheels, an electric drive device that drives the driving wheels, a braking device that applies braking to the wheels, and an operation of the steering wheels. A steering device and a magnetic field generated by a guide line laid along the travel path are detected from the left and right sides of the guide line on the vehicle body side, and a detection signal including information on the distance to the guide line is output. Steering control means for controlling the steering device based on the left guidance sensor and the right guidance sensor and the steering device based on the outputs of the left guidance sensor and the right guidance sensor to keep each wheel positioned on the road An electromagnetic induction type electric vehicle equipped with a controller is provided.

In the present invention, the controller determines whether or not the derailment state has occurred by setting a state where the steering control based on the outputs of the left guidance sensor and the right guidance sensor cannot be normally performed as a derailment state. A derailment determining means for determining a derailment direction, a derailment braking control means for controlling the braking device to stop the vehicle body when the derailment determination means determines that a derailment state has occurred, and a derailment braking control means Steering control based on the output of the left guidance sensor and the output of the right guidance sensor is normally performed in a state where the stopped vehicle body is fixed in a state where the rudder is turned to the same side as the derailment direction determined by the derailment determination means. A derailment return control means for performing a derailment return control for controlling the steering device, the electric drive device, and the braking device so as to be moved back to a position where it can be performed. It is.

  In the present invention, when the derailment determination means determines that the traveling vehicle has derailed, the braking device is controlled by the derailment braking control means to stop the vehicle body. It is possible to prevent the vehicle from traveling in an unexpected direction.

  In the present invention, the derailment return control means controls the steering device, the electric drive device, and the braking device, so that the vehicle body derailed and stopped is on the same side as the derailment direction determined by the derailment determination means. The steering device, the electric drive device, and the braking device are controlled so as to move back to a position where the steering control based on the output of the left guidance sensor and the output of the right guidance sensor can be normally performed in a state where the steering is turned off. Therefore, the derailed vehicle body can be automatically returned to a normal state.

  According to the present invention, it is possible to perform control for returning the derailed vehicle body to a normal state only by using the left and right induction sensors. Therefore, as in the invention described in Patent Document 3, four induction sensors are provided. Control can be simplified compared with the case of using. Further, according to the present invention, since it is not necessary to increase the number of induction sensors, it is possible to provide a function of automatically returning from a derailed state to a normal state without causing an increase in cost.

  According to a second aspect of the present invention, in the first aspect of the present invention, the steering control means controls the steering device so that the deviation between the output of the left guidance sensor and the output of the right guidance sensor is kept below a set value. The derailment determination means is configured to perform derailment when the deviation between the output of the left guidance sensor and the output of the right guidance sensor exceeds the derailment determination value set to the above set value or more. It is configured to determine that a state has occurred.

  When the steering control means is configured as described above, the deviation between the output of the left guidance sensor and the output of the right guidance sensor is kept below the set value when the electric vehicle is traveling correctly on the road. However, when the direction of the vehicle body is greatly deviated and the steering control based on the outputs of the left and right guidance sensors cannot return to the normal state (derailed or will be derailed soon The deviation between the output of the left guidance sensor and the output of the right guidance sensor exceeds the set value. Therefore, it is possible to determine whether or not the traveling vehicle has derailed from the travel path by determining whether or not the deviation between the outputs of the left and right induction sensors exceeds the derailment determination value set to a set value or more. .

  The invention described in claim 3 is the invention described in claim 2, wherein the derailment determination value is an output of the left and right guidance sensors when one of the left guidance sensor and the right guidance sensor is positioned directly above the guidance line. Is set to a value that is equal to or less than a value corresponding to a deviation occurring during the time period and exceeds the set value.

  If the control range of the vehicle body position in the steering control is set narrowly, the steering control is normally operated before the position shift amount becomes large until one of the left and right guidance sensors reaches a position directly above the guidance line. If the control range of the vehicle body position in steering control is set wide, steering control can be performed until one of the left and right guidance sensors reaches a position directly above the guidance line. it can. Therefore, the derailment determination value is equal to or less than a value corresponding to a deviation generated between outputs of the left and right guidance sensors when one of the left guidance sensor and the right guidance sensor is positioned directly above the guidance line, and the set value is It can be set to a value that exceeds.

  According to a fourth aspect of the present invention, in the first aspect of the present invention, the steering control means controls the steering device so that the deviation between the output of the left guidance sensor and the output of the right guidance sensor is kept below a set value. The deviation between the output of the left guidance sensor and the output of the right guidance sensor is determined so that the steering control is performed by the control, and the derailment determination means performs the steering control while the vehicle body is traveling. It is configured to determine that a derailment state has occurred when a state that does not fall below the set value occurs within a set time.

  When the vehicle is running while steering control is being performed and steering control is normally performed, the deviation between the output of the left guidance sensor and the output of the right guidance sensor converges to the set value or less within the set time. To do. Therefore, when the deviation between the output of the left guidance sensor and the output of the right guidance sensor falls within the set value within the set time, it can be determined that the steering control is normally performed, and the left guidance sensor When the state where the deviation between the output and the output of the right guidance sensor does not fall below the set value occurs within the set time, it can be determined that the derailment state has occurred.

  According to a fifth aspect of the present invention, in the first aspect of the present invention, the steering control means controls the steering device so that the deviation between the output of the left guidance sensor and the output of the right guidance sensor is kept below a set value. It is configured to perform steering control by controlling, and when the derailment determining means outputs any one of the left guidance sensor and the right guidance sensor, each guidance sensor is located immediately above the guidance line. It is configured to determine that a derailment state has occurred when a determination value set to a value equal to or slightly smaller than the peak value of the output generated at the time is reached.

  In the invention described in claim 6, in the invention described in claim 2, 3, 4 or 5, the output of the left induction sensor is more than the output of the right induction sensor in a state where it is determined that the derailment state has occurred. And when it is determined that a derailment state has occurred, and when the output of the right guidance sensor is greater than the output of the left guidance sensor, it is determined that the vehicle body has derailed in the right direction and derailed in the left direction. The derailment determining means is configured to perform the determination.

  When the traveling vehicle derails to the left with respect to the guidance line, the output of the right guidance sensor is greater than the output of the left guidance sensor, and when the traveling vehicle derails to the right, the output of the left guidance sensor is greater than the output of the right guidance sensor. Therefore, it is possible to determine whether the traveling vehicle has derailed to the left side or to the right side by comparing the outputs of the left and right induction sensors.

  In the invention described in claim 7, in the invention described in claim 2 or 3, steering control is normally performed when the deviation between the output of the left guidance sensor and the output of the right guidance sensor is equal to or less than a set value. The derailment return control means is configured to stop the vehicle body when the vehicle has moved back to a position where it can be performed.

  The invention described in claim 8 is the invention described in any one of claims 1 to 7, wherein the vehicle body is stopped by the derailment braking control means after the controller determines that the derailment determination means has derailed. Derailment braking distance measurement means that measures the distance traveled by the vehicle body before derailment as derailment braking distance, and derailment return distance measurement that measures the retreat distance of the vehicle body when derailment return control is performed And the vehicle body is forced when the reverse distance measured by the reverse distance measuring means at the time of derailment exceeds the shorter one of the braking distance during derailment or the preset allowable maximum reverse distance. The derailment return control means is configured to stop automatically.

  As described above, the vehicle body is forcibly stopped when the reverse distance measured by the reverse distance measuring means at the time of derailment exceeds the shorter one of the braking distance at the time of derailment or the preset allowable maximum reverse distance. With this configuration, it is possible to prevent the vehicle body from being greatly deviated from the traveling road when the direction of turning the rudder is wrong due to a malfunction.

  The invention described in claim 9 is the invention described in any one of claims 1 to 8, wherein the derailment return control means determines the rudder of the steering wheel by the derailment determination means when performing the derailment return control. The vehicle body is configured to be retracted in a state of being fixed in a state of being fully cut on the same side as the derailment direction.

  As described above, after stopping the derailed vehicle body, if the vehicle body is retracted with the rudder fully fixed to the same side as the derailment direction, it is necessary to return the vehicle body to its normal position. The reverse distance can be made equal to or less than the braking distance at the time of derailment, and in most cases, the vehicle body can be returned to the normal state only by retreating by a distance shorter than the braking distance at the time of derailment.

  According to the present invention, a state in which steering control based on the output of the left guidance sensor and the output of the right guidance sensor cannot be performed normally is defined as a derailment state, and whether or not the derailment state has occurred and the derailment direction is determined. The derailment determination means for performing the determination is provided, and when it is determined that the derailment state has occurred, the braking device is controlled by the braking control means at the time of derailment so that the vehicle body is stopped. When derailed, it can be prevented from running away from the road.

  Further, according to the present invention, the derailment return control means controls the steering device, the electric drive device, and the braking device, so that the vehicle body derailed and stopped is on the same side as the derailment direction determined by the derailment determination means. In the state where the rudder is turned off, the vehicle body is moved back to a position where the steering control based on the output of the left guidance sensor and the output of the right guidance sensor can be normally performed. Can be automatically restored.

  In addition, according to the present invention, since it is possible to control the derailed vehicle body to return to a normal state only by using the left and right induction sensors, signal processing is performed as compared with the case of the prior art using four induction sensors. Can be easy. Further, according to the present invention, since it is not necessary to increase the number of induction sensors, it is possible to have a function of automatically returning from a derailed state to a normal state without causing an increase in cost.

  According to the invention as set forth in claim 8, when the reverse distance measured by the derailment return reverse distance measuring means exceeds the shorter one of the derailment braking distance or the preset allowable maximum reverse distance. Since the derailment return control means is configured to forcibly stop the vehicle body, it is possible to prevent the vehicle body from greatly deviating from the road when the rudder is turned in the wrong direction during the return control due to malfunction etc. Can increase the sex.

  According to the ninth aspect of the present invention, when the derailed vehicle body is stopped and controlled to return to the normal state, the rudder is fixed to the same side as the derailment direction. Therefore, the retraction distance required to return the vehicle body to the normal state can be made less than or equal to the braking distance during derailment, and in most cases, the vehicle body is retracted by a distance shorter than the braking distance during derailment. Just return to normal.

1 is a configuration diagram illustrating an overall configuration of an electric traveling vehicle according to an embodiment of the present invention. It is the block diagram which showed the structure of the principal part of the electric traveling vehicle concerning embodiment of this invention. It is explanatory drawing explaining the operation | movement at the time of returning the derailed electric vehicle to a normal state. It is the graph which showed an example of the relationship between the output voltage of an induction sensor, and the distance between an induction sensor and an induction line. (A) is the graph which showed an example of the change which the output of a left guidance sensor and a right guidance sensor shows when a traveling vehicle derails to the right side to the direction of travel. (B) is the graph which showed an example of the change which the output of a left guidance sensor and a right guidance sensor shows when a traveling vehicle derails to the left side to the direction of travel. It is the flowchart which showed an example of the algorithm of the process which the computer which comprises a controller in one Embodiment of this invention performs. It is the flowchart which showed an example of the algorithm of the derailment direction determination process which a controller performs in order to comprise a derailment determination means in one Embodiment of this invention.

  Referring to FIG. 1, a configuration example of a riding golf cart 1 is shown as an example of an electric traveling vehicle to which the present invention is applied. In the figure, 2 and 2 are left and right steering wheels attached to a vehicle body (not shown), and 3 and 3 are left and right drive wheels. In this embodiment, the steering wheels 2 and 2 are front wheels, and the driving wheels 3 and 3 are rear wheels. A steering device 4 is provided to operate the steering wheels 2 and 2.

  The illustrated steering device 4 is a rocker that converts a steering motor 6 that is operated by a driving current from a steering motor driver 5 and a rotation that is given from the steering motor 6 through a gear transmission mechanism 7 and a steering shaft 8 to a linear motion. A displacement conversion mechanism 10 such as a rack and pinion mechanism or a ball screw mechanism that transmits to the arm 9, a knuckle arm 11 or 11 that transmits the displacement of the rocker arm 9 to the steering wheels 2 and 2, and a steering operated during manual operation And a wheel 12.

  A sensor mounting plate 13 is attached to the front end of the vehicle body. The sensor mounting plate 13 is provided so as to face the steering wheel 2 and 2 in the same direction as the steering wheel, and the left guidance sensor 14a and the right guidance sensor 14b are attached to the sensor mounting plate. The left and right induction sensors 14a and 14b are sensors that detect an alternating magnetic field generated from a guide wire 15 laid along a travel path (not shown) and generate an electrical signal proportional to the detected magnetic field strength. As the inductive sensors 14a and 14b, a sensor such as a search coil, a hall sensor, or a magnetoresistive element that detects magnetism by converting it into an electric signal can be used. In this embodiment, the left and right inductive sensors 14a and 14b are used. A search coil is used.

  The guide wire 15 extends along the longitudinal direction (traveling direction) of the travel path below the center in the width direction of the vehicle body when the steering wheels 2 and 2 and the drive wheels 3 and 3 are correctly placed on the travel path. Are laid like so. The left guidance sensor 14a and the right guidance sensor 14b are arranged in a state where they are positioned on the left side and the right side with respect to the forward direction of the vehicle body, respectively, and when the vehicle body position on the road route is within a normal range, The AC magnetic field generated from the induction wire 15 laid along the line is detected from the left and right sides of the induction wire 15. A low frequency (for example, 1500 Hz) alternating current is passed through the induction wire 15.

  A brake 18 is attached to the steering wheels 2 and 2 and the drive wheels 3 and 3 to generate a braking force when an operating force is applied from the hydraulic cylinder 17. The piston of the hydraulic cylinder 17 is driven via the gear 22 when the piston is pushed by the force applied from the brake pedal 19 and by the rotation of the brake motor 21 that operates by receiving a drive current from the brake motor driver 20. When this occurs, an operating force is applied to each brake 18 to generate a braking force from each brake. In this example, a brake 18, a brake pedal 19, a hydraulic cylinder 17, a brake motor driver 20, a brake motor 21, a gear 22, a pipe connecting the brake pedal 19 and the hydraulic cylinder 17, and hydraulic pressure A brake device 23 that applies braking to the steering wheel 2 and the drive wheel 3 is configured by a pipe connecting the cylinder 17 and each brake 18.

  A traveling motor 25 to which a drive current is applied from a motor driver 24 and a transmission 26 for transmitting the rotation of the motor to the drive wheels 3 and 3 are attached to the vehicle body. The transmission 26 is attached with an electromagnetic clutch brake 27 that restrains the rotation shaft of the traveling motor 25 and brakes the rotation, and a rotation sensor 28 that generates a pulse every time the motor 25 rotates by a minute angle. . The electromagnetic clutch brake 27 includes a restraining means for restraining the rotation shaft of the traveling motor 25 and a solenoid for operating the restraining means. When the solenoid is energized, the rotation of the traveling motor 25 by the restraining means is performed. The shaft is unconstrained and allowed to rotate. When the solenoid is not energized, the rotation shaft of the traveling motor 25 is restrained by the restraining means to prevent the rotation. In this example, the motor driver 24, the running motor 25, and the transmission 26 constitute an electric drive device 29 that applies rotational torque to the drive wheels 3 using the motor 25 as a power source.

  A battery 30 is also mounted on the vehicle body, and electric power is supplied to each part from this battery. In order to control each part, the controller 31 which comprises various control means by having a computer run a predetermined program is provided.

  The controller 31 includes output signals Sha and Shb from the induction sensors 14a and 14b, an accelerator signal Sa generated by the accelerator device 32, a brake signal Sb provided from a brake switch that operates when the brake pedal 18 is depressed, The pulse signal Sp generated by the rotation sensor 28, the start / stop command signal S1 generated by the start / stop switch 33, and the start / stop command signal generated by the receiver 35 that receives the start / stop command generated by the remote controller 34. S2, a start / stop command signal S3 given from the manual / automatic operation changeover switch 36, an inclination angle detection signal S4 generated by an inclination sensor 37 for detecting the inclination angle of the vehicle body, and a command such as a traveling speed to the traveling vehicle The speed command signal S5 generated by the magnet sensor 38 for detecting the permanent magnet embedded in the travel path is input. .

  The driving course provided on the golf course has a flat straight road, a steep uphill or downhill, or a sharp curve. Therefore, in order to ensure safety and driving performance during automatic driving, It is necessary to adjust the traveling speed according to the road condition. For this reason, in the present embodiment, a plurality of permanent magnets that indicate the traveling speed are embedded in the necessary places on the traveling path, such as before the curve and before the slope, by the arrangement pattern of the magnetic poles facing the ground surface. By detecting the arrangement pattern of the magnetic poles of the magnet by the magnet sensor 38, an instruction for the optimum traveling speed is received at various points on the traveling path. In addition, in order to accurately control the braking force on the slope, the inclination angle of the slope where the traveling vehicle is traveling is detected by the inclination sensor 37.

  As shown in FIG. 2, the controller 31 causes the computer to execute a predetermined program, thereby causing the electromagnetic clutch brake control means 31 </ b> A for controlling the electromagnetic clutch brake 27 and the traveling motor for controlling the traveling motor 25. Various control means including a control means 31B, a normal operation braking control means 31C for controlling the brake 17 during normal operation, and a steering control means 31D for controlling the steering device 4 are configured.

  The electromagnetic clutch brake control means 31 </ b> A energizes the electromagnetic clutch brake 27 when the accelerator pedal of the accelerator device 32 is depressed and the supply of drive current to the motor 25 is started, thereby restraining the rotation shaft of the traveling motor 25. In other words, when it is detected that the rotational speed of the motor 25 detected from the cycle of the pulse generated by the rotation sensor 28 is equal to or lower than the set value, the energization to the electromagnetic clutch brake 27 is stopped and the motor 25 for traveling is stopped. The electromagnetic clutch brake 27 is controlled so as to restrain the rotating shaft.

  The travel motor control means 31B supplies drive current to the travel motor 25 when the accelerator pedal of the accelerator device 32 is depressed while the manual operation mode is selected by the manual operation / automatic operation switch 36. The driving current is supplied to the motor 25 so as to rotate the traveling motor 25 at a rotational speed corresponding to the depression amount of the accelerator pedal, and the driving current to the traveling motor 25 is returned when the accelerator pedal is returned. And the motor driver 24 is controlled so that a braking current flows from the motor 25 through the driver 24.

  The traveling motor control means 31B also gives a start command from the start / stop switch 33 when the automatic operation mode is selected by the manual operation / automatic operation switch 36 or from the remote controller 34. When this is the case, the traveling motor 25 is set so that the deviation between the command speed given from the magnet sensor 38 and the vehicle speed obtained from the rotational speed of the motor detected from the pulse generation interval output from the rotation sensor 28 becomes zero. The driving current supplied to the vehicle is controlled so that the traveling vehicle travels at the indicated speed. When the passenger feels danger and steps on the brake, or the start / stop switch 33 generates a stop command. Sometimes, the supply of the drive current to the traveling motor 25 is stopped and the braking current is made to flow from the motor 25 through the driver 24. To control the Tadoraiba 24.

  When the automatic driving mode is selected, the normal operation braking control means 31C performs braking according to the vehicle speed detected by the speed sensor 28, the inclination angle of the traveling path detected by the inclination sensor 37, and the like. The brake motor driver 20 is controlled so as to generate a predetermined braking force from 18.

  The steering control means 31D controls the steering device 4 based on the output of the left guidance sensor 14a and the output of the right guidance sensor 14b when the automatic operation mode is selected by the manual operation / automatic operation changeover switch 36. The steering control which maintains each wheel in the state located on the travel path is performed.

  The steering control means 31D controls the steering motor 6 of the steering device 4 so as to keep the deviation between the output voltage of the left guidance sensor 14a and the output voltage of the right guidance sensor 14b below a set value (preferably to a minimum). Steering control is performed. The magnitude of the output voltage of the left guidance sensor 14a is almost inversely proportional to the distance between the left guidance sensor 14a and the guidance line 15, and the magnitude of the output voltage of the right guidance sensor 14b is between the right guidance sensor 14b and the guidance line. Is almost inversely proportional to the distance between Therefore, when the steering control as described above is performed, the steering motor 6 is controlled so as to keep the guide wire 15 positioned substantially at the center between the left guide sensor 14a and the right guide sensor 14b, thereby driving the vehicle. It can be run along the road.

  The electromagnetic clutch brake control means 31A, the traveling motor control means 31B, the normal operation braking control means 31C, and the steering control means 31D are also provided in the conventional golf cart, but in the present embodiment, these control means In addition, a derailment determination unit 31E, a derailment braking control unit 31F, a derailment return control unit 31G, a derailment braking distance measurement unit 31H, and a derailment return backward distance measurement unit 31I are provided in the controller. Yes.

  The derailment determination means 31E determines whether or not the derailment state has occurred and derails the state where the steering control based on the output of the left guidance sensor 14a and the output of the right guidance sensor 14b cannot be normally performed as the derailment state. It is a means for determining the direction. In the present embodiment, it is determined that a derailment state has occurred when the deviation between the output voltage of the left induction sensor 14a and the output voltage of the right induction sensor 14b exceeds a derailment determination value set to a set value or more. When it is determined that a state has occurred, the output voltage of the left induction sensor 14a is greater than the output voltage of the right induction sensor 14b and the output voltage of the right induction sensor 14b is greater than the output voltage of the left induction sensor 14a. The derailment determining means is configured to determine that the vehicle body has derailed in the right direction and that it has derailed in the left direction when the vehicle is large.

  FIG. 4 shows the relationship between the voltage V output from the induction sensor including the search coil and the distance X between the induction sensor and the induction line. As shown in the figure, the output voltage V of the induction sensor changes almost in inverse proportion to the distance X between the induction sensor and the induction line. In FIG. 4, X1 indicates each guidance when the left guidance sensor 14a and the right guidance sensor 14b are equidistant from the guidance line 15 (when the guidance line 15 is located at the center between the left and right guidance sensors). This is a distance between the sensor and the guide wire 15, and Vref is a voltage signal output from each guide sensor when the distance between each guide sensor and the guide wire is X1.

  When ideal steering control is performed, the output voltage of the left induction sensor 14a and the output voltage of the right induction sensor 14b are both Vref (the deviation between the output of the left induction sensor and the output of the right induction sensor is zero). It has become. Actually, it is inevitable that a slight misalignment occurs in the steering control due to a delay in the control, etc., so the deviation between the output of the left guidance sensor and the output of the right guidance sensor is kept below the set value. Control is performed as follows.

  If the amount of deviation of the left and right guidance sensors from the guide line becomes excessive during the process of performing such control, the deviation between the left guidance sensor output and the right guidance sensor output exceeds the set value. It may become impossible to perform normal steering control. In addition, the amount of deviation from the normal state of the vehicle body direction or position is increased, and one of the left and right induction sensors is further displaced beyond the position directly above the induction line, and both the left and right induction sensors are When the guidance sensor is located on the same side (left side or right side) with respect to the guide line, the guidance sensor located near the guide line is controlled in a direction away from the guide line. Control is performed in a direction away from the vehicle, and steering control cannot be performed correctly.

  In the present invention, a state in which steering control based on the output of the left guidance sensor and the output of the right guidance sensor cannot be normally performed is defined as a derailment state, and determination of whether the derailment state has occurred and determination of the derailment direction When it is determined that a derailment has occurred, the wheels are braked to stop the vehicle body, and then the rudder of the steered wheels is turned to the same side as the direction when it is determined that the derailment has occurred. In a fixed state, derailment return control is performed in which the steering control based on the output of the left guidance sensor and the output of the right guidance sensor is moved back to a position where the steering control can be normally performed.

  When the vehicle derails in the right direction, the distance between the left guidance sensor 14a and the guidance line 15 is longer than the distance between the right guidance sensor 14b and the guidance line 15, and the output voltage of the left guidance sensor 14a is It becomes larger than the output voltage of the induction sensor 14b. When the vehicle derails in the left direction, the distance between the right guidance sensor 14b and the guidance line 15 is longer than the distance between the left guidance sensor 14a and the guidance line 15, and the output voltage of the right guidance sensor 14b is It becomes larger than the output voltage of the left induction sensor 14a.

  Accordingly, the output voltages obtained from the left induction sensor 14a and the right induction sensor 14b when derailed in the right direction at time t1 change as shown in FIG. 5A, and when derailed in the left direction at time t1. The output voltages obtained from the left guidance sensor 14a and the right guidance sensor 14b change as shown in FIG. As is clear from FIGS. 5A and 5B, when the vehicle body derails in the right direction, the output voltage of the left induction sensor becomes higher than the output voltage of the right induction sensor, and when the vehicle body derails in the left direction, The output voltage of the right induction sensor is higher than the output voltage of the left induction sensor.

  The derailment determination means 31E of the present embodiment determines that a derailment state has occurred when the deviation between the output of the left guidance sensor and the output of the right guidance sensor exceeds the derailment determination value set to a set value or more, When the output of the left guidance sensor is greater than the output of the right guidance sensor and when the output of the right guidance sensor is greater than the output of the left guidance sensor, it is determined that the vehicle body has derailed to the right and derailed to the left. It is comprised so that determination may be performed.

  The derailment determination value is set to a value that can accurately detect the derailment state. If the control range of the vehicle body position in the steering control is set narrowly, the steering control is normally operated before the position shift amount becomes large until one of the left and right guidance sensors reaches a position directly above the guidance line. If the control range of the vehicle body position in steering control is set wide, steering control can be performed until one of the left and right guidance sensors reaches a position directly above the guidance line. it can. Therefore, the derailment determination value is equal to or less than a value corresponding to a deviation generated between the outputs of the two induction sensors when one of the left guidance sensor 14a and the right guidance sensor 14b is positioned directly above the guidance line 15. A value exceeding the set value can be set. The derailment determination value is preferably determined to an appropriate value based on experimental results so that it can be reliably determined whether or not a derailment state has occurred.

  The derailing braking control means 31F is a means for controlling the braking device 23 so that the steering wheel 2 and the driving wheel 3 are braked to stop the vehicle body when it is determined by the derailing determining means 31E that a derailing state has occurred. .

  Further, the derailment return control means 31G turns the vehicle body stopped by the derailment braking control means 31F in the state where the steering is turned to the same side as the derailment direction determined by the derailment determination means 31E, and the output of the left guidance sensor 14a. Derailment return control for controlling the steering device 4, the electric drive device 29, and the braking device 23 so that the steering device 4 is retracted and stopped from the output of the right guidance sensor 14 b until it is confirmed that steering control is possible. It is a means to perform.

  The steering direction when performing derailment return control may be the same as the steering direction when it is determined that derailment has occurred, but the reverse distance during derailment return control is shortened to promptly return to normal from the derailment state. In order to return to the derailment, it is preferable to perform derailment return control with the rudder fully fixed on the same side as the derailment direction.

  In the derailment return control, various methods for determining whether or not the steering control has returned to a normal state can be considered. In this embodiment, the output of the left guidance sensor 14a and the output of the right guidance sensor 14b When the deviation becomes less than the set value, it is determined that the steering control can be normally performed.

  In the present embodiment, a derailing braking distance measuring means 31H and a derailing return backward distance measuring means 31I are provided in order to prevent the backward distance when performing the derailment return control from becoming excessive. The derailment braking distance measuring means 31H is defined as a derailment braking distance, which is the distance traveled by the vehicle from the time when the derailment determination means 31E determines that the derailment has occurred until the vehicle is stopped by the derailment braking control means 31F. The derailment return backward distance measuring means 31I is a means for sequentially measuring the reverse distance of the vehicle body when the derailment return control is performed.

  The distance traveled between the time when the derailment determining unit 31E determines that the vehicle has been derailed and the time when the vehicle body is stopped by the derailment braking control unit 31F is, for example, the time when the vehicle body has been derailed Can be obtained by counting pulses generated by the rotation sensor 28 until the motor stops and multiplying the counted value by the travel distance per pulse. The retreat distance of the vehicle body when the derailment return control is being performed is the number of pulses generated by the rotation sensor 28 when the derailment return control is being performed, and the travel distance per pulse is added to the counted value. It can be obtained by multiplying.

  The derailment return control means 31G of the present embodiment is a state in which the vehicle body stopped by the derailment braking control means 31F is fixed in a state where the rudder is fully turned to the same side as the derailment direction determined by the derailment determination means 31E. When it is confirmed that the deviation between the output of the left guidance sensor 14a and the output of the right guidance sensor 14b is equal to or less than a set value (steering control can be normally performed). While the vehicle body is stopped, while the vehicle body is being retracted, the reverse distance that is sequentially measured by the reverse distance measurement means 31I at the time of derailment is the shorter of the derailment braking distance or the preset allowable maximum reverse distance The vehicle body is forcibly stopped when the vehicle exceeds the limit. The allowable maximum retreat distance is set to 1 m, for example.

  FIG. 6 is a flowchart showing an algorithm of a main part of processing to be executed by the computer constituting the controller 31. When this algorithm is followed, in step 101, the output voltages of the left and right induction sensors 14a and 14b are read and stored, and in step 102, it is determined whether or not the deviation of the output voltages of the left and right induction sensors is equal to or less than the derailment determination value. Thus, the presence or absence of derailment is determined. If the deviation between the output voltages of the left and right inductive sensors is equal to or less than the derailment determination value, the process returns to step 101 because no derailment has occurred. If it is determined in step 102 that the deviation between the output voltages of the left and right inductive sensors exceeds the derailment determination value, it is determined that derailment has occurred and the process proceeds to step 103 to brake the wheel and measure the braking distance. To do. In step 104, it is determined whether or not the wheel has stopped. When the vehicle has not stopped, the process returns to step 103 and the measurement of the braking distance is continued.

  When it is determined in step 102 that derailment has occurred, derailment direction determination processing shown in FIG. 7 is performed. In the derailment direction determination process of FIG. 7, the outputs of the left and right induction sensors are compared in step 201, and when the output of the left induction sensor is larger than the output of the right induction sensor, it is stored that the derailment is performed on the right side in step 202. When the output of the right guidance sensor is larger than the output of the left guidance sensor, it is stored in step 203 that the line has been derailed to the left.

  When it is determined in step 104 in FIG. 6 that the vehicle body has stopped, it is determined in step 105 whether the derailment direction determined in the derailment direction determination process in FIG. 7 is the left side or the right side. As a result, when it is determined that the derailment is on the left side, the rudder is fully turned to the left in step 106, and when it is determined that the derailment is on the right side, the rudder is fully turned to the right in step 107.

  After step 106 or 107 is performed and the rudder is fully turned to the left or right side, the process proceeds to step 108 for driving so that the drive wheels are rotated in the backward direction at a low speed while the rudder is fully turned. The motor 25 is controlled to retract the vehicle body at a low speed. At this time, the output distance of the rotation sensor 28 is counted by the reverse distance measuring means 31I at the time of derailment return to measure the reverse distance of the vehicle. After starting the reverse of the vehicle body at a low speed, it is determined in step 109 whether or not the deviation of the left and right induction sensor outputs is equal to or less than the set value. In step 109, the deviation of the left and right induction sensor outputs is equal to or less than the set value. If not, the routine proceeds to step 110, where it is determined whether or not the traveling distance exceeds the shorter of the derailment braking distance or the preset allowable maximum reverse distance (1 m in this example). As a result, when it is determined that the travel distance does not exceed the shorter of the derailment braking distance or the preset allowable maximum reverse distance, the routine returns to step 108. When it is determined that the travel distance exceeds the shorter of the derailment braking distance or the preset allowable maximum reverse distance, the routine proceeds to step 111 where the driving of the travel motor 25 is stopped and the brake motor 21 is turned off. The vehicle is stopped by driving and braking the wheels. Next, at step 112, it is determined whether or not the deviation between the outputs of the left and right induction sensors is equal to or less than a set value. As a result of the determination, if it is determined that the deviation is equal to or less than the set value, it is determined in step 113 that the vehicle can be restarted. If the deviation exceeds the set value, the vehicle is restarted in step 114. It is determined that it is impossible, and this process is terminated.

  In the case of the algorithm shown in FIGS. 6 and 7, the derailment determining means 31E is configured by the steps 101 and 102 and the derailment direction determining process of FIG. Further, steps 103 and 104 in FIG. 6 constitute derailment braking control means 31F, and steps 106 to 114 constitute derailment return control means 31G.

  FIG. 3 shows the return operation when the electric vehicle is in a derailed state in the above embodiment. When the direction of the electric traveling vehicle 1 is shifted to the right with respect to the guide wire 15, the wheels are braked and stopped. In this case, the traveling vehicle 1 stops in a state where it is tilted to the right with respect to the guide wire 15 as shown in FIG. From this state, with the rudder fully turned in the derailment direction, the traveling vehicle 1 is moved backward in the direction of the arrow B1 shown in the figure, and the deviation between the outputs of the left and right guidance sensors 14a and 14b as shown in FIG. Becomes equal to or less than the set value, and the traveling vehicle 1 is stopped when the guide wire 15 is located at the approximate center between the left and right guide sensors.

  When the direction of the electric traveling vehicle 1 is shifted to the left with respect to the guide wire 15, the wheels are braked and the traveling vehicle is stopped as shown in FIG. From this state, with the rudder fully turned in the derailment direction, the traveling vehicle 1 is moved backward in the direction of the arrow B2 shown in the figure, and the deviation between the outputs of the left and right guidance sensors 14a and 14b as shown in FIG. Becomes equal to or less than the set value, and the traveling vehicle 1 is stopped when the guide wire 15 is located at the approximate center between the left and right guide sensors.

  In the above embodiment, when the deviation between the output of the left guidance sensor 14a and the output of the right guidance sensor 14b exceeds a derailment determination value set to be equal to or greater than a set value that determines the control width (allowable fluctuation width) of the steering control. It is determined that a derailment state has occurred, but the output of either the left guidance sensor 14a or the right guidance sensor 14b occurs when the respective guidance sensor is positioned directly above the guidance line 15. The derailment determination means 31E may be configured to determine that a derailment state has occurred when a determination value set to a value that is equal to or slightly smaller than the peak value of the output is reached.

  The derailment determination means is also used when the deviation between the output of the left guidance sensor 14a and the output of the right guidance sensor 14b does not fall below the set value within the set time while the vehicle body is running while performing the steering control. It can also be configured to determine that a derailment state has occurred.

  In the above embodiment, the golf cart is taken as an example. However, the present invention is not limited to the golf cart, and is widely applied to an electric traveling vehicle that can automatically travel along a predetermined traveling path on which a guide wire is laid. be able to.

DESCRIPTION OF SYMBOLS 1 Electromagnetic induction type electric traveling vehicle 2 Steering wheel 3 Driving wheel 4 Steering device 5 Steering motor driver 6 Steering motor 8 Steering shaft 12 Steering wheel 13 Sensor mounting plate 14a Left guidance sensor 14b Right guidance sensor 15 Guide wire 17 Hydraulic cylinder 18 Brake 19 Brake pedal 20 Brake motor driver 21 Brake motor 23 Braking device 24 Motor driver 25 Traveling motor 26 Transmission 27 Electromagnetic clutch brake 28 Rotation sensor 29 Electric drive device 31 Controller 31A Electromagnetic clutch brake control means 31B Traveling motor control means 31C During normal operation Braking control means 31D Steering control means 31E Derailment determination means 31F Derailment braking control means 31H Derailment braking distance measurement means 31I Derailment Return during the recession distance measuring means

Claims (9)

A vehicle body including wheels including steering wheels and driving wheels, an electric drive device that drives the driving wheels, a braking device that applies braking to the wheels, a steering device that operates the steering wheels, and a travel path left inductive sensor and a right induction and outputs a detection signal containing information of the distance between the guiding line by detecting each magnetic field that laid down by guiding line is generated from the left and right sides of the guide wire in the body side Te A controller having steering control means for controlling the steering device based on the output of the sensor and the output of the left guidance sensor and the output of the right guidance sensor to keep each wheel positioned on the road In an electromagnetic induction electric vehicle with
The controller is
A state in which the steering control based on the output of the left guidance sensor and the output of the right guidance sensor cannot be normally performed is defined as a derailment state, and whether or not the derailment state has occurred and determination of the derailment direction are performed. Derailment judging means;
Derailment braking control means for controlling the braking device to stop the vehicle body when the derailment determination means determines that a derailment state has occurred;
With the vehicle body stopped by the derailment braking control means fixed in a state where the steering is turned to the same side as the derailment direction determined by the derailment determination means, the output of the left guidance sensor and the right guidance sensor Derailment return control means for performing derailment return control for controlling the steering device, the electric drive device, and the braking device so as to retract to a position where steering control based on the output can be normally performed,
An electromagnetic induction type electric traveling vehicle characterized by comprising: The steering control means is configured to perform the steering control by controlling the steering device so as to keep the deviation between the output of the left guidance sensor and the output of the right guidance sensor below a set value,
The derailment determining means determines that the derailment state has occurred when a deviation between the output of the left guidance sensor and the output of the right guidance sensor exceeds a derailment determination value set to be equal to or greater than the set value. That it is configured,
The electromagnetic induction type electric traveling vehicle according to claim 1. The derailment determination value is equal to or less than a value corresponding to a deviation generated between outputs of the left and right guidance sensors when one of the left guidance sensor and the right guidance sensor is positioned directly above the guidance line, and the set value is It is set to a value greater than
The electromagnetic induction type electric traveling vehicle according to claim 2. The steering control means is configured to perform the steering control by controlling the steering device so as to keep the deviation between the output of the left guidance sensor and the output of the right guidance sensor below a set value,
The derailment judging means is in a state where the deviation between the output of the left guidance sensor and the output of the right guidance sensor does not fall below the set value within a set time while the vehicle body is running while performing the steering control. Is configured to determine that the derailment state has occurred,
The electromagnetic induction type electric traveling vehicle according to claim 1. The steering control means is configured to perform the steering control by controlling the steering device so as to keep the deviation between the output of the left guidance sensor and the output of the right guidance sensor below a set value,
The derailment judging means is configured such that the output of either the left guidance sensor or the right guidance sensor is equal to or equal to the peak value of the output generated when the respective guidance sensor is positioned directly above the guidance line. Being configured to determine that a derailment state has occurred when a determination value set to a value slightly smaller than is reached,
The electromagnetic induction type electric traveling vehicle according to claim 1. The derailment determining means is in a state where it is determined that the derailment state has occurred, and when the output of the left guidance sensor is larger than the output of the right guidance sensor and in a state where it is determined that the derailment state has occurred. When the output of the right guidance sensor is larger than the output of the left guidance sensor, each vehicle body is configured to determine whether it has derailed in the right direction and to determine that it has derailed in the left direction,
The electromagnetic induction type electric traveling vehicle according to claim 2, 3, 4 or 5. The derailment return control means determines that the vehicle body has been moved back to a position where the steering control can be normally performed when a deviation between the output of the left guidance sensor and the output of the right guidance sensor becomes equal to or less than the set value. Be configured to stop,
The electromagnetic induction type electric traveling vehicle according to claim 2 or 3. The controller measures a distance traveled by the vehicle body from the determination that the derailment determination unit has derailed until the vehicle body is stopped by the derailment braking control unit as a derailment braking distance. Braking distance measuring means, and derailment return backward distance measurement means for measuring the backward distance of the vehicle body when the derailment return control is performed,
The derailment return control means forces the vehicle body when the reverse distance measured by the derailment return reverse distance measuring means exceeds the shorter of the derailment braking distance or a preset allowable maximum reverse distance. Is configured to stop automatically,
The electromagnetic induction type electric traveling vehicle according to any one of claims 1 to 7. When the derailment return control means performs the derailment return control, the steering wheel is fixed in a state where the rudder of the steered wheel is fully cut to the same side as the derailment direction determined by the derailment determination means. Being configured to retract,
The electromagnetic induction type electric traveling vehicle according to any one of claims 1 to 8.

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