JP2009201220A - Vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress abrupt changes in the body attitude, at a level difference ascending and descending, and to safely and comfortably run a vehicle, even in a place with the level difference by correcting a target value of vehicle acceleration, which is decided, according to a running command, so that anti-torque that acts on a vehicle body with level difference ascending and descending torque is offset by the inertial force of acceleration/deceleration. <P>SOLUTION: The vehicle is provided with the vehicle body, driving wheels fitted to the vehicle body so that they can rotate, an input device inputting a travel command and a vehicle controller controlling driving torque, given to the driving wheels and controlling the attitude of the vehicle body. The vehicle controller adds driving torque, corresponding to the level difference in the driving wheels during ascending/descending of the road surface level difference, and corrects the target value of vehicle acceleration which is decided, according to the travel command. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle using posture control of an inverted pendulum.

  Conventionally, a technique related to a vehicle using posture control of an inverted pendulum has been proposed. For example, a vehicle that has two drive wheels arranged on the same axis, detects a change in the posture of the vehicle body due to the driver's movement of the center of gravity, and drives the vehicle body attached to a single spherical drive wheel. Techniques for vehicles that move while being controlled have been proposed (see, for example, Patent Document 1).

In this case, the vehicle is stopped or moved by controlling the operation of the rotating body while detecting the balance of the vehicle body and the state of the operation with the sensor.
JP 2007-219986 A

  However, in the conventional vehicle, in the step elevation control, which is a control operation for adding drive torque for raising and lowering the step when getting on and off the step, the added drive torque is the gravitational torque due to the movement of the center of gravity of the vehicle body. Even if you try to control the vehicle attitude to cancel, the actual operation is delayed due to a sudden change in the target value of the vehicle attitude, resulting in insufficient control of the vehicle attitude, causing the vehicle to unnecessarily accelerate or decelerate. The car body may tilt greatly. This is because the response speed of the vehicle body posture control is generally lower than the response speed of the control for adding the drive torque, but a high output actuator is required to increase the response speed of the vehicle body posture control. As a result, the vehicle weight and cost increase. In addition, if the response speed of the control of the vehicle body posture is too high, the ride comfort is deteriorated for the passenger.

  The present invention solves the problems of the conventional vehicle, and the vehicle acceleration determined in accordance with the travel command so as to cancel the counter-torque acting on the vehicle body by the step up / down torque by the inertial force due to the acceleration / deceleration of the vehicle. By correcting the target value, an object is to provide a vehicle that can suppress a sudden change in the vehicle body posture when raising or lowering a step, and can safely and comfortably travel even in a place with a step.

  Therefore, in the vehicle of the present invention, based on a vehicle body, a drive wheel rotatably attached to the vehicle body, an input device for inputting a travel command, and the travel command input from the input device, the drive wheel And a vehicle control device that controls the posture of the vehicle body by controlling the drive torque applied to the vehicle, and the vehicle control device drives the drive wheel according to the level difference while raising and lowering the level difference on the road surface. And the target value of the vehicle acceleration determined according to the travel command is corrected.

  In another vehicle of the present invention, the vehicle control device further decreases the target value of the vehicle acceleration in the traveling direction when climbing the step on the road surface, and the traveling direction when descending the step on the road surface. The target value of the vehicle acceleration is increased.

  In still another vehicle of the present invention, the vehicle control device is further configured to cancel the counter-torque acting on the vehicle body by the driving torque added in accordance with the step with an inertial force due to acceleration / deceleration of the vehicle. Correct the target acceleration value.

  In still another vehicle of the present invention, the correction amount of the target value of the vehicle acceleration is set in proportion to the driving torque added according to the step.

  In still another vehicle of the present invention, the vehicle control device further includes a correction amount of the target value of the vehicle acceleration according to a predicted vehicle end speed that is a predicted vehicle speed at the completion of the elevation of the step. To change.

  In still another vehicle of the present invention, the predicted vehicle final speed value is a value of a rotational acceleration of the driving wheel, a step resistance torque that is a resistance caused by the step, and a vehicle acceleration determined according to the travel command. It is determined based on the target value.

  In still another vehicle of the present invention, the vehicle control device further corrects the target value of the vehicle acceleration when the predicted vehicle final speed is equal to or less than a predetermined first threshold (threshold) value. Set the amount to zero.

  In still another vehicle of the present invention, the vehicle control device further includes a vehicle body using a driving torque added in accordance with the step when the predicted vehicle final speed is equal to or greater than a predetermined second threshold value. The reference value, which is the correction value of the target value of the vehicle acceleration, such that the counter torque acting on the vehicle is equal to the torque acting on the vehicle body due to the inertial force accompanying the acceleration / deceleration of the vehicle is set as the correction value of the target value of the vehicle acceleration. .

  In still another vehicle of the present invention, the vehicle control device further includes the vehicle acceleration when the predicted vehicle final speed is in a range between the first threshold and the second threshold. The correction amount of the target value is shifted from zero to the reference value.

  According to the configuration of claim 1, by suppressing a sudden change in the vehicle body posture at the time of ascending / descending the step, it is possible to stably maintain the traveling state and the posture of the vehicle body both when climbing up and down the step, You can drive safely and comfortably in places with steps.

  According to the configuration of the second aspect, by performing correction of the target value of the vehicle acceleration suitable for the step that moves up and down, it is possible to realize the stable stepping on and off of any step.

  According to the configuration of the third aspect, by performing correction of the target value of the vehicle acceleration suitable for the vehicle speed, it is possible to realize a stable step-on / off for any vehicle speed.

  According to the configuration of the fourth aspect, it is possible to reliably prevent the correction of the target value of the vehicle acceleration so that the step cannot be fully climbed when the vehicle speed is low.

  According to the structure of Claim 5, the target value of vehicle acceleration can be more appropriately corrected with respect to an arbitrary vehicle speed by accurately predicting the vehicle final speed.

  According to the configuration of the sixth aspect, when the vehicle speed is high, it is possible to realize a comfortable stepping on and off of the step by raising and lowering the step without changing the vehicle body posture at all.

  According to the configuration of the sixth aspect, it is possible to realize a safe and comfortable step-on / off of the step by preventing a sudden change in the running state or the posture of the vehicle body accompanying the switching of the control according to the vehicle speed.

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

  FIG. 1 is a schematic diagram showing the configuration of a vehicle in a first embodiment of the present invention, and shows a state in which an occupant is moving forward in an accelerated state, and FIG. 2 is a first embodiment of the present invention. 1 is a block diagram showing a configuration of a vehicle control system in FIG.

  In FIG. 1, reference numeral 10 denotes a vehicle according to the present embodiment, which includes a body portion 11, a drive wheel 12, a support portion 13, and a riding portion 14 on which an occupant 15 rides. Can be tilted. Then, the posture of the vehicle body is controlled similarly to the posture control of the inverted pendulum. In the example shown in FIG. 1, the vehicle 10 is accelerating in the direction indicated by the arrow A, and the vehicle body is tilted in the traveling direction.

  The drive wheel 12 is rotatably supported with respect to a support portion 13 that is a part of the vehicle body, and is driven by a drive motor 52 as a drive actuator. The axis of the drive wheel 12 exists in a direction perpendicular to the plane shown in FIG. 1, and the drive wheel 12 rotates around that axis. The drive wheel 12 may be singular or plural, but in the case of plural, the drive wheels 12 are arranged on the same axis in parallel. In the present embodiment, description will be made assuming that there are two drive wheels 12. In this case, each drive wheel 12 is independently driven by an individual drive motor 52. As the drive actuator, for example, a hydraulic motor, an internal combustion engine, or the like can be used, but here, the description will be made assuming that the drive motor 52 that is an electric motor is used.

  The main body 11 that is a part of the vehicle body is supported from below by the support 13 and is positioned above the drive wheels 12. The main body 11 has a riding section 14 that functions as an active weight section so that it can move relative to the main body 11 in the front-rear direction of the vehicle 10, in other words, relative to the tangential direction of the vehicle body rotation circle. It is attached so as to be movable.

  Here, the active weight part has a certain amount of mass, and actively corrects the position of the center of gravity of the vehicle 10 by moving it back and forth with respect to the main body part 11. The active weight portion does not necessarily need to be the riding portion 14. For example, the active weight portion may be a device in which a heavy peripheral device such as a battery is movably attached to the main body portion 11, a weight, a weight (Weight), a device in which a dedicated weight member such as a balancer is movably attached to the main body 11 may be used. Moreover, you may use together the boarding part 14, a heavy peripheral device, an exclusive weight member, etc.

  Further, in the present embodiment, for convenience of explanation, an example in which the riding part 14 in a state in which the occupant 15 is boarded functions as an active weight part will be described, but the occupant 15 is not necessarily in the riding part 14. For example, when the vehicle 10 is operated by remote control, the occupant 15 may not be on the riding section 14, or cargo may be loaded instead of the occupant 15.

  The riding section 14 is the same as a seat used in automobiles such as passenger cars and buses, and includes a seat surface section 14a, a backrest section 14b, and a headrest 14c, and is attached to the main body section 11 through a moving mechanism (not shown). ing.

  The moving mechanism includes a low-resistance linear moving mechanism such as a linear guide device and an active weight part motor 62 as an active weight part actuator. The active weight part motor 62 drives the riding part 14, and the main body part 11. The vehicle is moved back and forth in the vehicle traveling direction. As the active weight actuator, for example, a hydraulic motor, a linear motor, or the like can be used. However, here, the description will be made assuming that the active weight motor 62 that is a rotary electric motor is used.

  The linear guide device includes, for example, a guide rail attached to the main body 11, a carriage attached to the riding part 14 and sliding along the guide rail, a ball, a roller, and the like interposed between the guide rail and the carriage. Rolling elements. In the guide rail, two track grooves are formed linearly along the longitudinal direction on the left and right side surfaces thereof. Moreover, the cross section of the carriage is formed in a U-shape, and two track grooves are formed on the inner sides of the two opposing side surfaces so as to face the track grooves of the guide rail. The rolling elements are incorporated between the raceway grooves, and roll in the raceway grooves with the relative linear motion of the guide rail and the carriage. The carriage is formed with a return passage that connects both ends of the raceway groove, and the rolling elements circulate through the raceway groove and the return passage.

  The linear guide device includes a brake or a clutch that fastens the movement of the linear guide device. When the operation of the riding section 14 is unnecessary, such as when the vehicle 10 is stopped, the relative positional relationship between the main body section 11 and the riding section 14 is maintained by fixing the carriage to the guide rail with a brake. . When the operation is necessary, the brake is released and the distance between the reference position on the main body 11 side and the reference position on the riding section 14 is controlled to be a predetermined value.

  An input device 30 including a joystick 31 as a target travel state acquisition device is disposed beside the boarding unit 14. The occupant 15 controls the vehicle 10 by operating a joystick 31 as a control device, that is, inputs a travel command such as acceleration, deceleration, turning, in-situ rotation, stop, and braking of the vehicle 10. ing. If the occupant 15 can operate and input a travel command, other devices such as a pedal, a handle, a jog dial, a touch panel, and a push button can be obtained instead of the joystick 31 to obtain a target travel state. It can also be used as a device.

  In addition, when the vehicle 10 is steered by remote control, it can replace with the said joystick 31, and can use the receiver which receives the driving | running | working command from a controller with a wire communication or a radio | wireless as a target driving | running | working state acquisition apparatus. Further, when the vehicle 10 automatically travels according to predetermined travel command data, a data reader that reads travel command data stored in a storage medium such as a semiconductor memory or a hard disk is used as a target travel instead of the joystick 31. It can be used as a status acquisition device.

  In addition, the vehicle 10 includes a control ECU (Electronic Control Unit) 20 as a vehicle control device, and the control ECU 20 includes a main control ECU 21, a drive wheel control ECU 22, and an active weight unit control ECU 23. The control ECU 20, main control ECU 21, drive wheel control ECU 22 and active weight control ECU 23 include calculation means such as a CPU and MPU, storage means such as a magnetic disk and a semiconductor memory, input / output interfaces, and the like. The computer system controls the operation. For example, the computer system is disposed in the main body 11, but may be disposed in the support portion 13 or the riding portion 14. The main control ECU 21, the drive wheel control ECU 22, and the active weight control ECU 23 may be configured separately or may be configured integrally.

  The main control ECU 21 functions as a part of the drive wheel control system 50 that controls the operation of the drive wheel 12 together with the drive wheel control ECU 22, the drive wheel sensor 51, and the drive motor 52. The drive wheel sensor 51 includes a resolver, an encoder, and the like, functions as a drive wheel rotation state measuring device, detects a drive wheel rotation angle and / or rotation angular velocity indicating a rotation state of the drive wheel 12, and transmits it to the main control ECU 21. To do. The main control ECU 21 transmits a drive torque command value to the drive wheel control ECU 22, and the drive wheel control ECU 22 supplies an input voltage corresponding to the received drive torque command value to the drive motor 52. The drive motor 52 applies drive torque to the drive wheels 12 in accordance with the input voltage, thereby functioning as a drive actuator.

  The main control ECU 21 functions as a part of the active weight part control system 60 that controls the operation of the riding part 14 that is the active weight part together with the active weight part control ECU 23, the active weight part sensor 61, and the active weight part motor 62. To do. The active weight part sensor 61 is composed of an encoder or the like, functions as an active weight part movement state measuring device, detects the active weight part position and / or movement speed indicating the movement state of the riding part 14, and transmits it to the main control ECU 21. To do. Further, the main control ECU 21 transmits an active weight part thrust command value to the active weight part control ECU 23, and the active weight part control ECU 23 sends an input voltage corresponding to the received active weight part thrust command value to the active weight part motor. 62. The active weight motor 62 applies thrust to the riding section 14 to translate the riding section 14 in accordance with the input voltage, thereby functioning as an active weight actuator.

  Further, the main control ECU 21 functions as a part of the vehicle body control system 40 that controls the posture of the vehicle body together with the drive wheel control ECU 22, the active weight unit control ECU 23, the vehicle body inclination sensor 41, the drive motor 52, and the active weight unit motor 62. . The vehicle body tilt sensor 41 includes an acceleration sensor, a gyro sensor, and the like, and functions as a vehicle body tilt state measuring device. The vehicle body tilt sensor 41 detects a vehicle body tilt angle and / or tilt angular velocity indicating the tilt state of the vehicle body, and transmits the detected vehicle body tilt angle to the main control ECU 21. The main control ECU 21 transmits a drive torque command value to the drive wheel control ECU 22 and transmits an active weight portion thrust command value to the active weight portion control ECU 23.

  The main control ECU 21 receives a travel command from the joystick 31 of the input device 30. Then, the main control ECU 21 transmits a drive torque command value to the drive wheel control ECU 22 and transmits an active weight portion thrust command value to the active weight portion control ECU 23.

  Further, the control ECU 20 functions as a step resistance torque estimating means for estimating the step resistance torque based on the travel state of the vehicle 10 and the time change of the vehicle body posture. Further, it functions as a target vehicle body posture determination means for determining a target vehicle body posture, that is, a vehicle body tilt state and / or an active weight portion movement state, according to the target travel state and the step resistance torque. Furthermore, it functions as an actuator output determining means that determines the output of each actuator according to the traveling state and vehicle body posture of the vehicle 10 acquired by each sensor, and the target traveling state, target vehicle body posture, and step resistance torque. Specifically, it functions as step elevation torque determining means for determining the drive torque to be added according to the step resistance torque, and center of gravity correction amount determining means for determining the center of gravity correction amount of the vehicle body according to the step elevation torque.

  Each sensor may acquire a plurality of state quantities. For example, an acceleration sensor and a gyro sensor may be used together as the vehicle body tilt sensor 41, and the vehicle body tilt angle and the vehicle body tilt angular velocity may be determined from the measured values of both.

  Next, the operation of the vehicle 10 configured as described above will be described. First, an outline of the travel and attitude control process will be described.

  FIG. 3 is a schematic view showing the step-up / down operation of the vehicle in the first embodiment of the present invention, and FIG. 4 is a flowchart showing the operation of the vehicle travel and attitude control processing in the first embodiment of the present invention. . FIG. 3A shows an example of operation according to the prior art for comparison, and FIG. 3B shows the operation according to the present embodiment.

  In the case of a conventional vehicle as described in the “Background Art” section, as shown in FIG. 3A, the reaction of the drive torque applied to the drive wheels 12 to climb up the step, that is, the anti-torque is applied to the vehicle body. The vehicle body tilts backward. For this reason, it is not possible to perform stable vehicle body posture and travel control when riding on a step.

  In contrast, in the present embodiment, the riding section 14 functions as an active weight section, and as shown in FIG. 3B, the center of gravity position of the vehicle 10 is set by moving the riding section 14 back and forth. Actively correct. As a result, the center of gravity of the vehicle body is moved forward when riding on the step, so that the reaction when the driving torque for riding on the step is applied to the drive wheel 12, that is, even if the anti-torque acts on the vehicle body, It will not tilt backwards. Therefore, stable vehicle body posture and travel control can be performed even when riding on a step. This embodiment is particularly effective when entering a step from a stopped state and a low-speed traveling state.

  Further, the driving torque for climbing up the step is estimated in real time during the climbing operation and applied to the drive wheels 12. Thereby, it is possible to stably ride on a step having an arbitrary shape.

  In other words, in the present embodiment, the vehicle 10 can move up and down in a stable manner by executing the travel and posture control processing including the correction of the center of gravity of the vehicle 10 and the application of drive torque.

  In the running and posture control process, the control ECU 20 first executes a state quantity acquisition process (step S1), and the driving wheel is driven by each sensor, that is, the driving wheel sensor 51, the vehicle body tilt sensor 41, and the active weight sensor 61. 12 rotation states, vehicle body inclination states, and riding portion 14 movement states are acquired.

  Next, the control ECU 20 executes a step elevation torque determination process (step S2), and obtains the state quantity obtained by the state quantity obtaining process, that is, the rotation state of the drive wheels 12, the lean state of the vehicle body, and the riding section 14. The step resistance torque is estimated by the observer based on the movement state and the output values of the actuators, that is, the output values of the drive motor 52 and the active weight motor 62, and the step elevation torque is determined. Here, the observer is a method of observing the internal state of the control system based on a dynamic model, and is configured by wired logic or soft logic.

  Next, the control ECU 20 executes a target travel state determination process (step S3), and based on the operation amount of the joystick 31, the target value of the acceleration of the vehicle 10 and the target value of the rotational angular velocity of the drive wheels 12 are obtained. decide.

  Next, the control ECU 20 executes a target body posture determination process (step S4), and the step lift torque determined by the step lift torque determination process and the acceleration of the vehicle 10 determined by the target travel state determination process. Based on the target value, the target value of the vehicle body posture, that is, the target value of the vehicle body inclination angle and the active weight portion position is determined.

  Finally, the control ECU 20 executes an actuator output determination process (step S5), each state quantity acquired by the state quantity acquisition process, the step lift torque determined by the step lift torque determination process, and the target travel state The output of each actuator, that is, the output of the drive motor 52 and the active weight motor 62, is determined based on the target travel state determined by the determination processing of the target vehicle body and the target vehicle body posture determined by the determination processing of the target vehicle body posture. To do.

  Next, details of the traveling and attitude control processing will be described. First, the state quantity acquisition process will be described.

  FIG. 5 is a diagram showing a vehicle dynamic model and its parameters according to the first embodiment of the present invention, and FIG. 6 is a flowchart showing an operation of state quantity acquisition processing according to the first embodiment of the present invention.

In the present embodiment, state quantities and parameters are represented by the following symbols. FIG. 5 shows some of the state quantities and parameters.
θ _W : Drive wheel rotation angle [rad]
θ ₁ : Body tilt angle (vertical axis reference) [rad]
λ _S : Active weight part position (vehicle center point reference) [m]
τ _W : Driving torque (total of two driving wheels) [Nm]
S _S : Active weight part thrust [N]
g: Gravity acceleration [m / s ² ]
m _W : Drive wheel mass (total of two drive wheels) [kg]
R _W : Driving wheel contact radius [m]
I _W : Moment of inertia of driving wheel (total of two driving wheels) [kgm ² ]
D _W : Viscosity damping coefficient [Ns / rad] with respect to drive wheel rotation
m ₁ : Body mass (including active weight) [kg]
l ₁ : Body center-of-gravity distance (from axle) [m]
I ₁ : Body inertia moment (around the center of gravity) [kgm ² ]
D ₁ : Viscous damping coefficient with respect to vehicle body tilt [Ns / rad]
m _S : Active weight part mass [kg]
l _S : Active weight part center of gravity distance (from axle) [m]
I _S : Active weight part inertia moment (around the center of gravity) [kgm ² ]
D _S : Viscosity damping coefficient [Ns / rad] for active weight part translation

  Next, the step elevation torque determination process will be described.

  FIG. 7 is a flowchart showing the operation of the step elevation torque determination process in the first embodiment of the present invention.

In the step elevation torque determination process, the main control ECU 21 first estimates the step resistance torque τ _D (step S2-1). In this case, based on each state quantity acquired in the state quantity acquisition process and the output of each actuator determined in the actuator output determination process in the previous (previous time step) travel and posture control process, The step resistance torque τ _D is estimated from (1).

Subsequently, the main control ECU 21 determines the step elevation torque τ _C (step S2-2). In this case, the estimated value of the step resistance torque τ _D is set as the value of the step lifting torque τ _C. That is, τ _C = τ _D.

  As described above, in the present embodiment, based on the driving torque output from the driving motor 52, the driving wheel rotation angular acceleration indicating the vehicle translational acceleration as the state quantity, the vehicle body inclination angular acceleration, and the active weight moving acceleration. Estimate the step resistance torque. In this case, not only the driving wheel rotation angular acceleration indicating the rotation state of the driving wheel 12, but also the vehicle body inclination angular acceleration and the active weight portion moving acceleration indicating the change in the vehicle body posture are considered. That is, the change in the vehicle body posture, which is a characteristic element of a vehicle using the posture control of the inverted pendulum, that is, the so-called inverted vehicle is taken into consideration.

  Conventionally, since the step resistance torque is estimated based on the drive torque and the driving wheel rotation angular acceleration, a large error may occur in the estimated value of the step resistance torque especially when the posture of the vehicle body is changing. . However, in the present embodiment, the step resistance torque is estimated in consideration of the vehicle body inclination angle acceleration indicating the change in the posture of the vehicle body and the active weight portion moving acceleration, so that a large error does not occur and the step is highly accurate. The resistance torque can be estimated.

  Generally, in an inverted type vehicle, the center of gravity of the vehicle body moves back and forth relative to the drive wheels, so that the center of gravity of the vehicle may move back and forth even when the drive wheels are stopped. Therefore, in order to estimate the step resistance torque with high accuracy from the acceleration of the center of gravity and the driving force or the driving torque, it is necessary to consider such an influence. In a general inverted type vehicle, the weight ratio of the vehicle body with respect to the entire vehicle is high, and the change in posture during the step-up / down operation is large, so such an effect becomes large.

  In the present embodiment, the step resistance torque that changes during the step-up / down operation is always estimated. For example, if a constant drive torque is applied to the drive wheels 12 during the step-up / down operation, the vehicle 10 may be unnecessarily accelerated / decelerated immediately before the end of the lift. This is because, for example, when riding on a step, the step resistance torque decreases as the vehicle 10 climbs the step. Therefore, in this embodiment, the step resistance torque that changes with the step elevation state is estimated in real time, and the value is constantly updated so that the step elevation torque suitable for the step elevation operation is always applied. It has become.

  Note that the high frequency component of the estimated value can be removed by applying a low pass filter to the estimated value of the step resistance torque. In this case, a time delay occurs in the estimation, but the vibration caused by the high frequency component can be suppressed.

  In the present embodiment, only the inertial force is considered, but the rolling resistance of the driving wheel 12, the viscous resistance due to the friction of the rotating shaft, the air resistance acting on the vehicle 10, etc. are considered as secondary effects. May be.

  In the present embodiment, a linear model related to the rotational motion of the drive wheel 12 is used. However, a more accurate nonlinear model may be used, or a model for vehicle body tilting motion or active weight portion translational motion. May be used. For nonlinear models, functions can also be applied in the form of maps.

  Further, in order to simplify the calculation, it is not necessary to consider the change in the body posture.

  Next, the target travel state determination process will be described.

  FIG. 8 is a flowchart showing the operation of the target travel state determination process in the first embodiment of the present invention.

  In the determination process of the target travel state, the main control ECU 21 first acquires a steering operation amount (step S3-1). In this case, the occupant 15 acquires the operation amount of the joystick 31 that is operated to input a travel command such as acceleration, deceleration, turning, on-site rotation, stop, and braking of the vehicle 10.

  Subsequently, the main control ECU 21 determines a target value for vehicle acceleration based on the acquired operation amount of the joystick 31 (step S3-2). For example, a value proportional to the amount of operation of the joystick 31 in the front-rear direction is set as a target value for vehicle acceleration.

Subsequently, the main control ECU 21 calculates the target value of the drive wheel rotational angular velocity from the determined target value of the vehicle acceleration (step S3-3). For example, by integrating the target value of the vehicle acceleration time, a value obtained by dividing the driving wheel contact radius R _W and the target value of the drive wheel rotation angular velocity.

  Next, the target vehicle body posture determination process will be described.

  FIG. 9 is a graph showing changes in the target value of the active weight portion position and the target value of the vehicle body tilt angle in the first embodiment of the present invention, and FIG. 10 shows the target vehicle body posture in the first embodiment of the present invention. It is a flowchart which shows the operation | movement of a determination process.

In the target body posture determination process, the main control ECU 21 first determines the target value of the active weight portion position and the target value of the vehicle body tilt angle (step S4-1). In this case, based on the target value of the vehicle acceleration determined by the determination process of the target traveling state and the step lift torque τ _C acquired by the determination process of the step lift torque, the following expressions (2) and (3) are used: The target value of the active weight portion position and the target value of the vehicle body inclination angle are determined.

  Subsequently, the main control ECU 21 calculates the remaining target value (step S4-2). That is, the target values of the drive wheel rotation angle, the vehicle body inclination angular velocity, and the active weight portion moving speed are calculated by time differentiation or time integration of each target value.

Thus, in the present embodiment, not only the inertial force and drive motor reaction torque acting on the vehicle body in accordance with the vehicle acceleration, but also acting on the vehicle body with the step lifting torque τ _C corresponding to the step resistance torque τ _D. The target value of the vehicle body posture, that is, the target value of the active weight portion position and the target value of the vehicle body tilt angle are determined in consideration of the counter torque.

  At this time, the center of gravity of the vehicle body is moved so that the torque that acts on the vehicle body to tilt the vehicle body, that is, the vehicle body tilt torque is canceled out by the action of gravity. For example, when the vehicle 10 climbs a step, the riding section 14 is moved forward, or the vehicle body is further tilted forward. Further, when the vehicle 10 goes down the step, the riding section 14 is moved rearward, or the vehicle body is further tilted rearward.

  In the present embodiment, as shown in FIG. 9, first, the riding section 14 is moved without tilting the vehicle body, and when the riding section 14 reaches the active weight movement limit, the tilting of the vehicle body is started. . For this reason, the vehicle body does not tilt forward and backward with respect to fine acceleration / deceleration, so that the ride comfort for the occupant 15 is improved. Further, if the level difference is not particularly high, the vehicle body is kept upright even on the level difference, so that it is easy to secure the field of view for the occupant 15. In addition, if the level difference is not particularly high, the vehicle body does not greatly tilt even on the level difference, so that a part of the vehicle body is prevented from contacting the road surface.

  In the present embodiment, it is assumed that the active weight part movement limit is equal between the front and the rear, but when the front and rear are different, the inclination of the vehicle body is changed according to each limit. The presence or absence may be switched. For example, when the braking performance is set higher than the acceleration performance, it is necessary to set the rear active weight portion movement limit farther than the front limit.

  In this embodiment, when the acceleration is low or the level difference is low, only the movement of the riding section 14 is used, but some or all of the vehicle body tilt torque may be handled by the vehicle body tilt. Good. By tilting the vehicle body, the front-rear inertial force acting on the occupant 15 can be reduced.

  Furthermore, in the present embodiment, an expression based on a linearized dynamic model is used, but an expression based on a more accurate nonlinear model or a model considering viscous resistance may be used. Note that if the equation is nonlinear, the function can be applied in the form of a map.

  Next, the actuator output determination process will be described.

  FIG. 11 is a flowchart showing the operation of the actuator output determination process in the first embodiment of the present invention.

In the actuator output determination process, the main control ECU 21 first determines the feedforward output of each actuator (step S5-1). In this case, the feedforward output of the drive motor 52 is determined by the following equation (4) from each target value and the step lifting torque τ _C, and the feedforward of the active weight motor 62 is determined by the following equation (5). Determine the output.

Thus, by automatically adding the step lifting torque τ _C according to the step resistance torque τ _D , that is, by correcting the driving torque according to the step resistance torque τ _D , when the step is raised or lowered Can also provide the same handling feeling as the flat ground. That is, it is possible to get on and off the level difference by the same steering operation as that on the flat ground. In addition, the vehicle 10 is not unnecessarily accelerated or decelerated when the level difference is raised or lowered with respect to a certain steering operation of the joystick 31.

  Thus, in the present embodiment, more accurate control is realized by theoretically giving a feedforward output.

  Note that the feed-forward output can be omitted as necessary. In this case, the feedback control indirectly gives a value close to the feedforward output with a steady deviation. Further, the steady deviation can be reduced by applying an integral gain.

  Subsequently, the main control ECU 21 determines the feedback output of each actuator (step S5-2). In this case, the feedback output of the drive motor 52 is determined by the following equation (6) from the deviation between each target value and the actual state quantity, and the feedback output of the active weight unit motor 62 by the following equation (7). To decide.

Note that nonlinear feedback control such as sliding mode control can also be introduced. As simpler control, some of the feedback gains excluding K _W2 , K _W3, and K _S5 may be set to zero. Further, an integral gain may be introduced in order to eliminate the steady deviation.

  Finally, the main control ECU 21 gives a command value to each element control system (step S5-3). In this case, the main control ECU 21 transmits the sum of the feedforward output and the feedback output determined as described above to the drive wheel control ECU 22 and the active weight part control ECU 23 as the drive torque command value and the active weight part thrust command value. .

As described above, in the present embodiment, the step resistance torque τ _D is estimated by the observer, the step lifting torque τ _C is applied, and the riding section 14 is moved in the upper direction of the step. Therefore, the vehicle body can be held upright even on the level difference, and the level difference can be raised and lowered. In addition, an apparatus for measuring a step is not required, and the system configuration can be simplified and the cost can be reduced.

Furthermore, since in view of the vehicle body inclination angle theta ₁ and active weight portion position lambda _S indicates the attitude of the vehicle body is estimated the step lifting torque tau _C, without a large error occurs, the step lifting torque tau _C with extremely high precision Can be estimated.

  Note that this embodiment is effective not only when climbing a step, but also when descending a step. The acceleration of the vehicle when the step is lowered is suppressed by applying the step lifting torque, and the vehicle body is held upright by moving the riding portion 14 backward. The same applies to the second and third embodiments described below.

  Next, a second embodiment of the present invention will be described. In addition, about the thing which has the same structure as 1st Embodiment, the description is abbreviate | omitted by providing the same code | symbol. The description of the same operation and the same effect as those of the first embodiment is also omitted.

  FIG. 12 is a block diagram showing the configuration of the vehicle control system in the second embodiment of the present invention, and FIG. 13 is a schematic diagram showing the operation in raising and lowering the step of the vehicle in the second embodiment of the present invention. .

  In the first embodiment, the riding part 14 is attached so as to be able to translate relative to the main body part 11 in the front-rear direction of the vehicle 10 and functions as an active weight part. In this case, a moving mechanism including the active weight motor 62 is disposed, and thereby the riding section 14 is translated, so that the control system is complicated as the structure becomes complicated and the cost and weight increase. On the other hand, the first embodiment cannot be applied to an inverted vehicle that does not have a moving mechanism for moving the riding section 14.

  Therefore, in the present embodiment, a moving mechanism for moving the riding section 14 is omitted. Also, as shown in FIG. 12, the active weight part control system 60 is omitted from the control system, and the active weight part control ECU 23, the active weight part sensor 61, and the active weight part motor 62 are omitted. Since the configuration of other points is the same as that of the first embodiment, description thereof is omitted.

  In the present embodiment, as shown in FIG. 13, when raising and lowering the step, the driving torque applied to the drive wheel 12 for raising and lowering the step, that is, the reaction to the step raising and lowering torque is applied to the vehicle body. By tilting the vehicle body in the upper direction of the step by an angle corresponding to the step lifting torque with respect to the vehicle body tilting torque acting as an anti-torque, the vehicle body tilting torque is canceled by the action of gravity to maintain a balance.

  In addition, as described in the section of “Background Art”, for example, when a required driving torque is applied to the driving wheel when riding on a step, the reaction acts on the vehicle body, so that the vehicle body is in a direction opposite to the step, that is, It will be greatly inclined in the lower direction of the step. On the other hand, if the posture of the vehicle body is to be maintained upright, the necessary driving torque cannot be applied to the driving wheels, so that it is impossible to ride on the step. In addition, the same phenomenon occurs when getting down the step, and the vehicle body tilts forward.

  In contrast, in the present embodiment, the vehicle body is intentionally tilted in the upper direction of the step by an angle suitable for the height of the step, so that a stable body posture can be maintained even when the step is raised or lowered. It is possible to travel safely and comfortably in places with steps.

  Next, details of the traveling and posture control processing in the present embodiment will be described. Note that the outline of the travel and attitude control process and the determination process of the target travel state are the same as those in the first embodiment, so the description is omitted, the state quantity acquisition process, the step elevation torque determination process, Only the target vehicle body attitude determination process and the actuator output determination process will be described. First, the state quantity acquisition process will be described.

FIG. 14 is a flowchart showing the operation of the state quantity acquisition process in the second embodiment of the present invention.

  Next, the step elevation torque determination process will be described.

  FIG. 15 is a flowchart showing the operation of the step elevation torque determination process in the second embodiment of the present invention.

In the step elevation torque determination process, the main control ECU 21 estimates the step resistance torque τ _D (step S2-11). In this case, based on each state quantity acquired in the state quantity acquisition process and the output of each actuator determined in the actuator output determination process in the previous run (previous time step) travel and posture control process, The step resistance torque τ _D is estimated from equation (8).

Subsequently, the main control ECU 21 determines the step elevation torque τ _C (step S2-12). In this case, the estimated value of the step resistance torque τ _D is set as the value of the step lifting torque τ _C. That is, τ _C = τ _D.

  Thus, in the present embodiment, the step resistance torque is estimated based on the driving torque output from the driving motor 52, the driving wheel rotation angular acceleration and the vehicle body inclination angular acceleration as the state quantities. In this case, not only the driving wheel rotation angular acceleration indicating the rotation state of the driving wheel 12 but also the vehicle body inclination angular acceleration indicating the change in the vehicle body posture is considered. That is, the change in the vehicle body posture, which is a characteristic element of a vehicle using the posture control of the inverted pendulum, that is, the so-called inverted vehicle is taken into consideration.

  Conventionally, since the step resistance torque is estimated based on the driving torque and the driving wheel rotation angular acceleration, a large error may occur in the estimated value of the step resistance torque especially when the posture of the vehicle body changes greatly. However, in the present embodiment, the step resistance torque is estimated in consideration of the vehicle body inclination angle acceleration indicating the change in the posture of the vehicle body, so that a large error does not occur and the step resistance torque can be estimated with high accuracy. it can.

  In the present embodiment, the step resistance torque that changes during the step-up / down operation is always estimated. For example, if a constant drive torque is applied to the drive wheels 12 during the step-up / down operation, the vehicle 10 may be unnecessarily accelerated / decelerated immediately before the end of the lift. This is because, for example, when riding on a step, the step resistance torque decreases as the vehicle 10 climbs the step. Therefore, in this embodiment, the step resistance torque that changes with the step elevation state is estimated in real time, and the value is constantly updated so that the step elevation torque suitable for the step elevation operation is always applied. It has become.

  As in the first embodiment, a high-frequency component of the estimated value can be removed by applying a low-pass filter to the estimated value of the step resistance torque. In this case, a time delay occurs in the estimation, but the vibration caused by the high frequency component can be suppressed.

  In the present embodiment, only the inertial force is considered, but the rolling resistance of the drive wheel 12, the viscous resistance due to the friction of the rotating shaft, the air resistance acting on the vehicle 10, etc. are secondary effects. You may consider it.

  Further, a more accurate nonlinear model may be used, or a model for vehicle body tilt motion may be used. For nonlinear models, functions can also be applied in the form of maps.

  Further, in order to simplify the calculation, it is not necessary to consider the change in the body posture.

  Next, the target vehicle body posture determination process will be described.

  FIG. 16 is a flowchart showing the operation of target body posture determination processing in the second embodiment of the present invention.

In the determination process of the target vehicle body posture, the main control ECU 21 first determines a target value of the vehicle body inclination angle (step S4-11). In this case, based on the target value of the vehicle acceleration determined by the target travel state determination process and the step lift torque τ _C acquired by the step lift torque determination process, the vehicle body inclination angle is expressed by the following equation (9). Determine the target value.

  Subsequently, the main control ECU 21 calculates the remaining target value (step S4-12). That is, the target values of the drive wheel rotation angle and the vehicle body inclination angular velocity are calculated by time differentiation or time integration of each target value.

Thus, in the present embodiment, not only the inertial force and drive motor reaction torque acting on the vehicle body in accordance with the vehicle acceleration, but also acting on the vehicle body with the step lifting torque τ _C corresponding to the step resistance torque τ _D. The target value of the vehicle body posture, that is, the target value of the vehicle body tilt angle is determined in consideration of the counter torque.

  At this time, the center of gravity of the vehicle body is moved so as to cancel the vehicle body tilt torque by the action of gravity. For example, when the vehicle 10 accelerates and climbs a step, the vehicle body is tilted forward. Further, when the vehicle 10 decelerates and descends a step, the vehicle body is tilted backward.

  In the present embodiment, an expression based on a linearized dynamic model is used, but an expression based on a more accurate nonlinear model or a model considering viscous resistance may be used. Note that if the equation is nonlinear, the function can be applied in the form of a map.

  Next, the actuator output determination process will be described.

  FIG. 17 is a flowchart showing the operation of the actuator output determination process in the second embodiment of the present invention.

In the actuator output determination process, the main control ECU 21 first determines the feedforward output of the actuator (step S5-11). In this case, the feedforward output of the drive motor 52 is determined from the target value and the step elevation torque τ _{C according} to the equation (4) described in the first embodiment.

As shown in the above equation (4), by automatically adding a step lifting torque τ _C corresponding to the step resistance torque τ _D , the same control feeling as on the flat ground is provided even when the step is raised or lowered can do. That is, it is possible to get on and off the level difference by the same steering operation as that on the flat ground. In addition, the vehicle 10 is not unnecessarily accelerated or decelerated when the level difference is raised or lowered with respect to a certain steering operation of the joystick 31.

  In the present embodiment, more accurate control is realized by theoretically giving a feedforward output, but the feedforward output can be omitted if necessary. In this case, the feedback control indirectly gives a value close to the feedforward output with a steady deviation. Further, the steady deviation can be reduced by applying an integral gain.

  Subsequently, the main control ECU 21 determines the feedback output of the actuator (step S5-12). In this case, the feedback output of the drive motor 52 is determined by the following equation (10) from the deviation between each target value and the actual state quantity.

Note that nonlinear feedback control such as sliding mode control can also be introduced. As a simpler control, some of the feedback gains excluding K _W2 and K _W3 may be set to zero. Further, an integral gain may be introduced in order to eliminate the steady deviation.

  Finally, the main control ECU 21 gives a command value to the element control system (step S5-13). In this case, the main control ECU 21 transmits the sum of the feedforward output and the feedback output determined as described above to the drive wheel control ECU 22 as a drive torque command value.

  As described above, in the present embodiment, the vehicle body can be tilted in the upper direction of the step to maintain the balance when the step is raised or lowered. Therefore, it can be applied to an inverted vehicle that does not have a moving mechanism for moving the riding section 14, and the structure and the control system are simplified, so that stable and low-level ingress and egress can be achieved even on an inexpensive and lightweight inverted vehicle. Can be realized.

  Next, a third embodiment of the present invention will be described. In addition, about the thing which has the same structure as 1st and 2nd embodiment, the description is abbreviate | omitted by providing the same code | symbol. Also, the description of the same operations and effects as those of the first and second embodiments is omitted.

  FIG. 18 is a schematic diagram showing the configuration of the vehicle according to the third embodiment of the present invention, showing a state where a step is detected before the step, and FIG. 19 is a vehicle according to the third embodiment of the present invention. FIG. 20 is a block diagram showing a configuration of a vehicle control system according to a third embodiment of the present invention. 18, (b) is an enlarged view of the main part of (a), and (a) to (c) in FIG. 19 show a series of operations.

  If a constant driving torque is applied to the drive wheels 12 during the step-up / down operation, the vehicle 10 may unnecessarily accelerate / decelerate immediately before the end of the step-up / down operation. This is because, for example, when riding on a step, the step resistance torque decreases as the vehicle 10 climbs the step.

  Therefore, in the present embodiment, a step in the traveling direction of the vehicle 10 is detected by a sensor, and the position and height of the step measured by the sensor and the rotation angle of the driving wheel corresponding to the raised / lowered state of the step are determined. The step lifting torque is changed.

  Therefore, in the present embodiment, the vehicle 10 includes a distance sensor 71 as a step measurement sensor, as shown in FIG. The distance sensor 71 uses, for example, laser light, but may be any type of sensor. In the example shown in FIG. 18, two distance sensors 71 are arranged on the lower surface of the riding section 14 so as to be separated from each other in the front-rear direction, and each measures the distance from the lower surface to the road surface. And the level | step difference of a road surface can be detected from the change of the measured value of each distance sensor 71, and the position and height of the detected level | step difference can be acquired. Desirably, one distance sensor 71 is disposed in front of a portion of the driving wheel 12 that contacts the road surface, and the other distance sensor 71 is disposed rearward of a portion of the driving wheel 12 that contacts the road surface. Is done. Thus, since the two distance sensors 71 measure the distance to the road surface at a position away from the contact point of the drive wheel 12, the step difference between the front and rear of the vehicle 10 can be detected.

  Moreover, the vehicle 10 has a level difference measurement system 70 including a distance sensor 71 as shown in FIG. Then, the distance sensor 71 detects the ground distance as the distance to the road surface at two points on the front and rear sides, and transmits it to the main control ECU 21.

  Thus, for example, when riding on a step, as shown in FIG. 19, the amount of movement of the riding section 14, the driving torque for riding on the step, etc. are changed as the vehicle 10 rises, thereby stabilizing the vehicle body posture. And travel control can be performed.

  Next, details of the traveling and posture control processing in the present embodiment will be described. The outline of the travel and attitude control process, the state quantity acquisition process, the target travel state determination process, the target vehicle body attitude determination process, and the actuator output determination process are the same as those in the first embodiment. The description will be omitted, and only the process for determining the step lifting torque will be described.

  FIG. 21 is a diagram showing a geometric condition when measuring an ascending step according to the third embodiment of the present invention, and FIG. 22 is a step ascending / descending resistivity of the ascending step according to the third embodiment of the present invention. FIG. 23 is a diagram showing a geometric condition when measuring a down step in the third embodiment of the present invention, and FIG. 24 is a down view in the third embodiment of the present invention. The figure which shows the change of the level | step difference raising / lowering resistivity of a level | step difference, FIG. 25: is a flowchart which shows the operation | movement of the determination process of the level | step difference raising / lowering torque in the 3rd Embodiment of this invention.

  In the step elevation torque determination process, the main control ECU 21 first acquires the measurement value of the distance sensor 71 (step S2-21). In this case, the measured value of the ground distance is acquired from the two front and rear distance sensors 71.

Subsequently, the main control ECU 21 determines the position and height of the step (step S2-22). In this case, determined by the time history of the ground distance obtained from the distance sensors 71, the vehicle body inclination angle theta _1, the position of the riding section 14, i.e., based on the active weight portion position lambda _S, the position and height of the step To do.

Subsequently, the main control ECU 21 determines the step resistance torque τ _D (step S2-23). In this case, the step resistance torque τ _D is calculated by the following equation (11).
τ _D = ξτ _{D, Max} (11)
Here, τ _{D, Max} is the maximum step resistance torque, and ξ is the step elevation resistance.

As shown in FIG. 21, when the step is ascending, that is, ascending, the maximum step resistance torque τ _{D, Max} and the step elevation resistivity ξ are expressed by the following equations (12) and (13). In FIG. 21, X is the distance to the step when the step is detected, and H is the height of the step. In the case of ascending stage, H is zero or more.

In addition, η ₀ is a virtual climbing angle and corresponds to a driving wheel rotation angle necessary for climbing a step. Θ _{W, S} is the driving wheel rotation angle when the driving wheel 12 contacts the step, and θ _{W, 0} is the driving wheel rotation angle when the step is detected. Further, Δθ _W is the driving wheel rotation angle after the step contact, and its value becomes zero when the driving wheel 12 contacts the step.

Then, the value of the step resistance torque τ _D changes as shown in FIG. That is, the maximum value τ _{D, Max} is reached when the drive wheel 12 contacts the step, gradually decreases during the ascending step, and becomes the minimum value of zero when the ascending step ends.

As shown in FIG. 23, when the step is down, that is, when the step is down, the maximum step resistance torque τ _{D, Max} and the step elevation resistivity ξ are expressed by the following equations (14) and (15). Is done. In FIG. 23, X is the distance to the step when detecting the step, and H is the height of the step, but in descending step, H is less than zero, that is, minus.

Then, the value of the step resistance torque τ _D changes as shown in FIG. That is, the minimum value is zero when the driving wheel 12 contacts the step, gradually decreases during the descending step, and reaches the maximum value τ _{D, Max} immediately before the end of the descending step.

Finally, the main control ECU 21 determines the step elevation torque τ _C (step S2-24). In this case, the estimated value of the step resistance torque τ _D is set as the value of the step lifting torque τ _C. That is, τ _C = τ _D.

As described above, in the step elevation torque determination process, the step resistance torque τ _D is changed in accordance with the step height H. That is, the value of the step resistance torque τ _D is increased as the value of the step height H is increased.

Further, the magnitude of the step resistance torque τ _D is changed in accordance with the step elevation state of the vehicle 10. That is, the elevation state of the vehicle 10 is estimated from the drive wheel rotation angle θ _W and the value of the step elevation resistivity ξ is changed. Thereby, it is possible to cope with a speed change of the vehicle 10.

Specifically, when climbing the step, that is, when the height H of the step is equal to or greater than zero, the step resistance torque τ _D (step elevation resistivity ξ) is decreased as the drive wheel rotation angle θ _W increases. This is because the driving torque required to support the vehicle 10 decreases as the level difference is increased.

On the other hand, when descending the step, that is, when the height H of the step is less than zero, the step resistance torque τ _D (step elevation resistivity ξ) is increased as the drive wheel rotation angle θ _W increases. This is because the driving torque required to support the vehicle 10 increases as the level difference is lowered.

  Thereby, the driving | running | working state of the vehicle 10 at the time of level | step difference raising / lowering can be controlled stably.

  In the present embodiment, only the case where the vehicle 10 moves forward and enters the step located in front of the vehicle 10 has been described. However, the same applies to the case where the vehicle 10 moves backward and enters the step located behind the vehicle 10. Control can be implemented.

  In the present embodiment, the case where the distance sensor 71 is not used during the step-up / down operation is described. However, in order to grasp the step-up / down state of the vehicle 10 more accurately, the measurement value of the distance sensor 71 is used. You can also Thereby, stable control can be performed even if the drive wheel 12 slips.

  Further, in the present embodiment, the case where a discontinuous function is used in the determination formula of the step elevation resistivity ξ has been described, but a function in which the discontinuous portion is continuously corrected can also be used. In addition, in order to prevent control chattering or vehicle operation hunting at discontinuous portions, hysteresis control (for example, control in which two threshold values are set and the threshold value is changed according to the rotation direction of the drive wheels 12) is introduced. Also good.

  Furthermore, in the present embodiment, the case of using a determinant based on a non-linear dynamic model has been described. However, for the sake of simplicity, a linear approximation formula may be used. Further, a more advanced determination formula that considers deformation of the drive wheel 12, rolling friction, slip conditions, and the like may be used.

As described above, in the present embodiment, the step in the traveling direction of the vehicle 10 is detected by the distance sensor 71, and according to the position and height H of the step measured by the distance sensor 71 and the driving wheel rotation angle θ _W. The value of the step elevation torque τ _C is changed. Therefore, the inverted posture of the vehicle body can be kept stable even when the step is raised or lowered. Thereby, the vehicle 10 can drive | work safely and comfortably also in the place with a level | step difference.

  In the present embodiment, the case where a step is detected and the position and height H of the step are measured by the two distance sensors 71 has been described. However, other devices and methods can be used. For example, the detection of the step and the position and height H of the step may be measured by acquiring an image of the traveling direction of the vehicle 10 with a camera and analyzing the acquired image. Further, for example, based on a vehicle position acquisition system that acquires the position of the vehicle 10 using GPS (Global Positioning System), and map data that includes information on the road surface and the level difference, the level difference that exists around the vehicle 10 is determined. Information may be acquired.

  Next, a fourth embodiment of the present invention will be described. In addition, about the thing which has the same structure as the 1st-3rd embodiment, the description is abbreviate | omitted by providing the same code | symbol. Explanation of the same operations and effects as those of the first to third embodiments is also omitted.

  FIG. 26 is a schematic diagram showing the step-up / down operation of the vehicle in the fourth embodiment of the present invention, FIG. 27 is a diagram showing a change in the final speed correction coefficient in the fourth embodiment of the present invention, and FIG. It is a flowchart which shows the operation | movement of the determination process of the target driving state in the 4th Embodiment of invention. FIG. 26A shows an operation example according to the first embodiment, and FIG. 26B shows an operation according to the present embodiment.

  In a control operation for adding drive torque for raising and lowering the step when the vehicle 10 gets on and off the step (hereinafter referred to as “step elevation control”), the added drive torque is the gravitational torque due to the movement of the center of gravity of the vehicle body. Even if the control of the vehicle body posture is canceled, the actual operation is delayed with respect to the sudden change in the target value of the vehicle body posture, so that the vehicle body posture control becomes insufficient and the vehicle 10 is unnecessarily accelerated or decelerated. Or the vehicle body may tilt significantly. This is because there is a time delay with respect to the setting of the target value in the control of the vehicle body inclination angle, which is the control of the vehicle body posture, and the position control of the riding section 14. That is, since the response speed of the vehicle body posture control is lower than the response speed of the control for adding the drive torque, the vehicle body posture control is unbalanced.

  Of course, it is possible to increase the response speed of the vehicle body posture control. For this reason, for example, if the moving speed of the riding section 14 is increased, the active weight section motor 62 having a high output is required as an actuator. The weight and cost of the vehicle 10 increase. Further, if the response speed of the vehicle body posture control is too high, the ride comfort for the occupant 15 may deteriorate.

Therefore, in the present embodiment, the target value of the vehicle acceleration determined based on the operation amount of the joystick 31 is corrected so that the vehicle body posture becomes constant during the elevation of the step. Specifically, as shown in FIG. 26 (b), when climbing a step, the step lift torque τ _C acts on the vehicle body so that the vehicle body posture is constant from the start to the end of the step lift. The target value of the vehicle acceleration is decreased so that the counter torque is canceled out by the inertial force due to the deceleration of the vehicle 10. That is, the target value of the vehicle acceleration is corrected so that the reaction torque acting on the vehicle body as the reaction of the step elevation torque τ _C necessary for the elevation of the step is balanced with the torque due to the inertial force accompanying the acceleration / deceleration of the vehicle 10.

Note that when the vehicle speed is low or the level difference is high, the elevation of the level difference cannot be completed, so the target value of the vehicle acceleration is not corrected. That is, as described in the first embodiment and as shown in FIG. 26 (a), the riding portion 14 is driven, and the reaction portion acting on the vehicle body by the step elevation torque τ _C is applied to the riding portion. The main body 11 is moved back and forth in the vehicle traveling direction so as to cancel out by gravity due to the movement of 14.

  As a result, it is possible to suppress a sudden change in the vehicle body posture when raising or lowering the step, and it is possible to travel safely and comfortably in a place with a step.

  Next, details of the traveling and posture control processing in the present embodiment will be described. The outline of the travel and posture control processing, the state quantity acquisition processing, the step elevation torque determination processing, the target vehicle body posture determination processing, and the actuator output determination processing are the same as those in the first embodiment. The description will be omitted, and only the target running state determination process will be described here.

  In the target travel state determination process, the main control ECU 21 first acquires a steering operation amount (step S3-11). In this case, the occupant 15 acquires the operation amount of the joystick 31 that is operated to input a travel command such as acceleration, deceleration, turning, on-site rotation, stop, and braking of the vehicle 10.

Subsequently, the main control ECU 21 determines a target value of vehicle acceleration based on the acquired operation amount of the joystick 31 (step S3-12). In this case, the target value α ^* of the vehicle acceleration is determined by the following equation (16) based on the operation amount of the joystick 31, the driving wheel rotation angular velocity, and the step resistance torque.

Here, ξ _VC is a final speed correction coefficient, and is changed as shown in FIG. 27 by a vehicle final speed predicted value V _f that is a value predicted from the vehicle speed when the vehicle 10 has finished climbing the step. . That is, the lower the vehicle final speed predicted value V _f is, the smaller the final speed correction coefficient ξ _VC is. Note that ξ _VC = 0 means that the target value of the vehicle acceleration is not corrected, and corresponds to executing the control as described in the first embodiment.

Specifically, the final speed correction coefficient ξ _VC is set by the following equation (18).

V _f0 and V _f1 are a low speed side threshold value as a first threshold value and a high speed side threshold value as a second threshold value of the vehicle final speed predicted value V _f , and are predetermined values set in advance. The predicted vehicle final speed V _f is given by the following equation (19).

Here, C _I is a parameter related to inertia, V is corrected vehicle speed, eta is a virtual uphill angle, the following equation (20), by (21) and (22) are represented respectively.

  Here, ε is a minute constant, and is a predetermined value set to prevent the denominator of the equation (19) from becoming zero.

  The virtual uphill angle η is the rotation angle of the drive wheel 12 necessary to complete the elevation of the step. For example, in the state where the drive wheel 12 is in contact with the step, as shown in FIG. The tangent of the peripheral surface at the contact point between the peripheral surface of the drive wheel 12 and the step is equal to the angle formed by the road surface (horizontal plane).

Finally, the main control ECU 21 calculates the target value of the drive wheel rotational angular velocity from the determined target value of the vehicle acceleration (step S3-13). For example, by integrating the target value of the vehicle acceleration time, a value obtained by dividing the driving wheel contact radius R _W and the target value of the drive wheel rotation angular velocity.

  Here, only the case where the vehicle moves forward and enters the step located at the front of the vehicle 10 has been described. However, the case where the vehicle moves backward and enters the step located at the rear of the vehicle 10 may also be changed. The same control can be performed for the case of lowering.

  In this way, the main control ECU 21 corrects the target value of the vehicle acceleration so that the vehicle body posture becomes constant during the step elevation.

  Specifically, the target value of the vehicle acceleration is corrected so that the counter-torque acting on the vehicle body as the counter-action of the step-up / down torque required for step-up / down is balanced with the torque caused by the inertial force accompanying the acceleration / deceleration of the vehicle 10. When the vehicle moves forward and goes up the step, the vehicle 10 is decelerated to generate an inertial force that tries to tilt the vehicle body forward so as to counteract the counter torque that tries to tilt the vehicle body backward as a reaction of the step lifting torque. At this time, the target vehicle acceleration correction amount reference value for realizing appropriate deceleration is set as a function proportional to the step elevation torque. Accordingly, it is possible to suppress an abrupt change in the vehicle body posture (the inclination angle of the vehicle body, the position of the riding section 14, etc.) during the step elevation, and to realize a stable and comfortable step elevation operation.

  Further, the correction amount of the target value of the vehicle acceleration is limited to prevent excessive correction. That is, by limiting the target vehicle acceleration correction amount reference value to the target vehicle acceleration correction amount maximum value, which is a predetermined maximum value, a mismatch with the control feeling of the occupant 15 due to automatic correction, and a sudden addition Prevents deterioration in ride comfort associated with deceleration.

  Furthermore, during low-speed traveling, the correction amount of the target value of vehicle acceleration is limited to prevent the attempt to raise or lower the step or the folding operation. Thereby, even when the vehicle enters the step at a low speed, the necessary step elevation control can be appropriately executed to realize stable step elevation.

  Specifically, step elevation can be completed when correction based on the target vehicle acceleration correction amount correction value is performed based on a vehicle end speed prediction value that is a value obtained by predicting vehicle speed at the time of completion of step elevation. Determine whether or not. Here, the vehicle final speed prediction value is based on a dynamic model, and the vehicle acceleration target according to the operation amount of the joystick 31 that determines the target value of the driving wheel rotation angular velocity, the step resistance torque, and the fixed vehicle body posture. Set as a function of value. Thereby, the vehicle final speed, which is an important determination factor, can be predicted more accurately.

  When the vehicle final speed predicted value is equal to or greater than a predetermined high speed side threshold value, the final speed correction coefficient is set to 1, and correction is performed. In other words, it is judged that there is a low possibility that the vehicle speed will greatly decrease and the attempt to raise or lower the step or the folding operation will occur, and by decelerating the vehicle, the step can be raised in a stable state without changing the vehicle body posture. .

  On the other hand, when the predicted vehicle final speed is less than or equal to a predetermined low speed side threshold, the final speed correction coefficient is set to 0 and no correction is performed. In other words, if the vehicle speed is greatly reduced, it is determined that there is a high possibility that an attempt to raise or lower a step or a turn-back operation will occur. Raise the step.

  In addition, when the vehicle end speed prediction value is between the high speed side threshold value and the low speed side threshold value, the final speed correction coefficient is given by a linearly interpolated function, so that Prevents sudden changes and vibrations that are periodically switched near the threshold.

  According to the above method, it is possible to easily realize an appropriate correction in consideration of the vehicle speed and the height of the step (the magnitude of the step resistance torque).

  In this embodiment, when the predicted vehicle end speed is equal to or greater than a predetermined high speed side threshold value, control for making the vehicle body posture constant by setting the final speed correction coefficient to 1, that is, control with priority on the vehicle body posture is performed. Although the example of performing was demonstrated, you may make it make a vehicle body attitude | position and a vehicle running state compatible to some extent by making a final speed correction coefficient into a value of 1 or less. Further, a parameter adjusting device may be provided on the joystick 31 that is a control device so that the occupant 15 can adjust the value of the final speed correction coefficient.

  Further, in the present embodiment, an example in which whether or not correction execution is possible is determined by comparing the vehicle end speed prediction value with the predetermined high speed side threshold value and the low speed side threshold value has been described. However, the current vehicle speed and the vehicle end speed are determined. Whether or not correction can be performed may be determined based on a difference or ratio with the predicted value, or another index.

  Furthermore, in the present embodiment, the example in which the vehicle end speed is predicted based on the measured value of the drive wheel rotation angular speed has been described, but the vehicle end speed may be predicted based on the target value of the drive wheel rotation angular speed. . As a result, it is possible to prevent the minute vibration of the rotational angular velocity of the driving wheel accompanying disturbance or the like from affecting the control, and to realize more stable step elevation control.

  Further, in the present embodiment, an example using a nonlinear function to determine the vehicle final speed predicted value and the virtual climb angle has been described. However, the calculation is performed by using a linear function approximating the nonlinear function. May be simplified. Further, a nonlinear function may be applied in the form of a map.

  Furthermore, in the present embodiment, the example in which the height of the step is estimated based on the estimated value of the step resistance torque and the vehicle end speed is predicted based on the estimated value has been described. However, in the third embodiment, the description is given. As described above, a step measurement sensor such as the distance sensor 71 may be used, and control may be executed based on the measurement result of the step measurement sensor.

  In addition, this invention is not limited to the said embodiment, It can change variously based on the meaning of this invention, and does not exclude them from the scope of the present invention.

It is the schematic which shows the structure of the vehicle in the 1st Embodiment of this invention, and is a figure which shows the state which is carrying out acceleration advance in the state which the passenger | crew got on. It is a block diagram which shows the structure of the control system of the vehicle in the 1st Embodiment of this invention. It is the schematic which shows the level | step difference raising / lowering operation | movement of the vehicle in the 1st Embodiment of this invention. It is a flowchart which shows operation | movement of the driving | running | working and attitude | position control processing of the vehicle in the 1st Embodiment of this invention. It is a figure which shows the dynamic model of the vehicle in the 1st Embodiment of this invention, and its parameter. It is a flowchart which shows the operation | movement of the acquisition process of the state quantity in the 1st Embodiment of this invention. It is a flowchart which shows the operation | movement of the determination process of the level | step difference raising / lowering torque in the 1st Embodiment of this invention. It is a flowchart which shows the operation | movement of the determination process of the target driving state in the 1st Embodiment of this invention. It is a graph which shows the change of the target value of the active weight part position in the 1st Embodiment of this invention, and the target value of a vehicle body tilt angle. It is a flowchart which shows the operation | movement of the determination process of the target vehicle body attitude | position in the 1st Embodiment of this invention. It is a flowchart which shows the operation | movement of the determination process of the actuator output in the 1st Embodiment of this invention. It is a block diagram which shows the structure of the control system of the vehicle in the 2nd Embodiment of this invention. It is the schematic which shows the operation | movement in the raising / lowering of the level | step difference of the vehicle in the 2nd Embodiment of this invention. It is a flowchart which shows the operation | movement of the acquisition process of the state quantity in the 2nd Embodiment of this invention. It is a flowchart which shows the operation | movement of the determination process of the level | step difference raising / lowering torque in the 2nd Embodiment of this invention. It is a flowchart which shows the operation | movement of the determination process of the target vehicle body attitude | position in the 2nd Embodiment of this invention. It is a flowchart which shows the operation | movement of the determination process of the actuator output in the 2nd Embodiment of this invention. It is the schematic which shows the structure of the vehicle in the 3rd Embodiment of this invention, and is a figure which shows the state which has detected the level | step difference before the level | step difference. It is the schematic which shows the operation | movement in the raising / lowering of the level | step difference of the vehicle in the 3rd Embodiment of this invention. It is a block diagram which shows the structure of the control system of the vehicle in the 3rd Embodiment of this invention. It is a figure which shows the geometric conditions when measuring the level | step difference of the up in the 3rd Embodiment of this invention. It is a figure which shows the change of the level | step difference raising / lowering resistivity of the uphill level | step difference in the 3rd Embodiment of this invention. It is a figure which shows the geometric conditions when measuring the level | step difference of the down in the 3rd Embodiment of this invention. It is a figure which shows the change of level | step difference raising / lowering resistivity of the level | step difference of the downward in the 3rd Embodiment of this invention. It is a flowchart which shows the operation | movement of the determination process of the level | step difference raising / lowering torque in the 3rd Embodiment of this invention. It is the schematic which shows the level | step difference raising / lowering operation | movement of the vehicle in the 4th Embodiment of this invention. It is a figure which shows the change of the final speed correction coefficient in the 4th Embodiment of this invention. It is a flowchart which shows the operation | movement of the determination process of the target driving state in the 4th Embodiment of this invention.

Explanation of symbols

10 Vehicle 12 Drive wheel 20 Control ECU
30 Input device

Claims (6)

The car body,
A drive wheel rotatably mounted on the vehicle body;
An input device for inputting a travel command;
A vehicle control device for controlling the posture of the vehicle body by controlling a drive torque applied to the drive wheel based on a travel command input from the input device;
The vehicle control device adds a driving torque corresponding to the step to the driving wheel during the elevation of the road step, and corrects the target value of the vehicle acceleration determined according to the travel command. Vehicle.   The vehicle control device decreases the target value of the vehicle acceleration when going up the road surface step, and increases the target value of the vehicle acceleration when going down the road step. The vehicle according to claim 1, wherein the value is corrected.   The vehicle control device corrects the target value of the vehicle acceleration by canceling a counter-torque acting on a vehicle body by an inertial force due to acceleration / deceleration of the vehicle by a driving torque added according to the step. Vehicle described in.   The vehicle according to any one of claims 1 to 3, wherein a correction amount of the target value of the vehicle acceleration is set in proportion to a driving torque added according to the step. Vehicle end speed prediction means for predicting a vehicle end speed prediction value that is a predicted vehicle speed at the completion of raising and lowering the step,
The vehicle according to any one of claims 1 to 4, wherein the vehicle control device changes a correction amount of a target value of the vehicle acceleration according to the predicted vehicle final speed value.   The vehicle control device sets a correction amount of the target value of the vehicle acceleration to zero when the predicted vehicle end speed is not more than a first threshold, and the estimated vehicle end speed is not less than a second threshold. In this case, the correction value of the target value of the vehicle acceleration is set as the reference value, and the target value of the vehicle acceleration is determined when the predicted vehicle end speed is in a range between the first threshold value and the second threshold value. The vehicle according to claim 5, wherein the correction amount is shifted from zero to a reference value.

Images