JP2015027185A - Personal vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a personal vehicle which reduces downhill turning at the beginning of cant travel and improves straight travel performance during the cant travel by performing a feedforward correction based on a position of the center of gravity.SOLUTION: A personal vehicle, including a vehicle body, right and left drive wheels, an operation unit, a drive part, a revolution speed detecting part, and a control unit, further includes a detection part of a yaw angular velocity ωY and a detection part of a position of the center of gravity of the vehicle body. The control unit includes: means for setting a target vehicle body angular velocity ω1 and a target straight advancing velocity based on a command signal; means 71 which corrects the target vehicle body angular velocity ω1 based on a difference Δω between the target vehicle body angular velocity ω1 and the yaw angular velocity ωY; means 72 which corrects the target vehicle body angular velocity ω1 based on a positional relationship (a right/left distribution ratio RF) between the right and left drive wheels and the position of the center of gravity; means for calculating a target revolution speed based on a post-correction target vehicle body angular velocity ω2 and the target straight advancing velocity; and means for controlling drive force of the drive part based on the target revolution speed and an actual revolution speed.

Description

  The present invention relates to a personal vehicle such as an electric wheelchair, and more particularly to a personal vehicle that reduces a single flow during canting.

  When running straight ahead (canting) across a road surface on which a personal vehicle such as an electric wheelchair is inclined, if the roll angle of the vehicle body (tilt angle in the left-right direction) is too large, the problem of uniflow occurs. Cheap. That is, despite the fact that the occupant is operating the operation unit so that the vehicle travels straight, the vehicle body tends to generate a single flow that travels toward the valley side (lower slope), and the personal vehicle travels straight. It tends to be damaged. Two factors can be considered as factors causing a single flow or a decrease in straight traveling performance: an imbalance of loads shared by the left and right drive wheels, and the generation of a turning moment.

  If the load shared by the left and right drive wheels is unbalanced depending on the occupant's seating posture, the left and right axle angular velocities will be different unless the driving torque is increased on the drive wheel that shares the large load. The personal vehicle cannot travel straight ahead. Further, in the driving wheel on the side sharing a large load, the tire is significantly compressed and deformed, and the effective radius is smaller than that on the other side. Then, even if the axle angular velocities of the left and right drive wheels are equal, the traveling speeds are not equal on the left and right, and the personal vehicle cannot travel straight. Furthermore, when the personal vehicle starts running, if the ratio of the starting torque is not appropriate for the load imbalance between the left and right drive wheels, one of the drive wheels starts to rotate first, and the commanded direction is The personal vehicle starts in a different direction.

  The load imbalance described above often occurs remarkably during cant traveling. That is, the drive wheels on the valley side (lower slope) share a large load, and the starting direction of the personal vehicle tends to flow in one direction from the direction crossing the inclined road surface toward the valley side. Furthermore, there is a possibility that the vehicle cannot travel straight after the vehicle starts and the traveling direction of the personal vehicle may gradually approach the direction of decreasing the slope.

  Further, during cant traveling, if the center of gravity of the total load including the vehicle body and the occupant is shifted in the front-rear direction with respect to the axle connecting the rotation centers of the left and right drive wheels, a turning moment is generated. For example, if the center of gravity shifts to the front side with respect to the axle, the load (gravity) acting on the center of gravity is considered to be decomposed into a component perpendicular to the inclined road surface and a component directed downward on the slope. The downward component generates a turning moment that turns the axle to the valley side. This turning moment changes approximately in proportion to the longitudinal distance between the center of gravity and the axle. Therefore, due to the turning moment, the traveling direction of the personal vehicle tends to be directed to the valley side (lower slope).

  The applicant of the present application discloses a personal vehicle control device in Patent Document 1 that reduces the above-described problem of one-way flow during canting. In the personal vehicle control device disclosed in Patent Document 1, when the personal vehicle cant travel, even if the roll angle of the personal vehicle is large, as long as the operation unit is operated so as to move straight, the vehicle body slippage is suppressed. A control unit is provided for controlling the personal vehicle so as to ensure straight running performance. Specifically, Patent Document 1 includes a sensor for detecting a physical quantity related to a roll angle and a yaw angle of a vehicle body. And a control part correct | amends a target vehicle body angular velocity command value with the feedforward term based on the detected roll angle, and gives a torque difference to a right-and-left driving wheel. Thereby, the single flow of the vehicle body at the start of cant traveling can be reduced. That is, the above-mentioned two factors are dealt with by feedforward control based on the roll angle.

JP 2010-193939 A

  By the way, with the technique of Patent Document 1, the target vehicle body angular velocity is feedforward corrected in advance according to the roll angle of the vehicle body. However, it is necessary to make fine adjustments to the software and the actual machine in consideration of the influence of the light weight of the occupant and the change in the center of gravity position of the total load. For this purpose, multiple sensors are used as sensors for detecting cost increase and roll angle and yaw angle. For example, complication of component configuration and an increase in component cost are caused by using an acceleration sensor and a gyro sensor together.

  The present invention has been made in view of the problems of the background art described above, and it is an object to be solved to provide a low-cost personal vehicle that can improve the straight traveling performance by reducing the single flow during cant traveling. .

  The personal vehicle of the present invention that solves the above-described problems includes a vehicle body, left drive wheels and right drive wheels provided on the left and right sides of the vehicle body, an operation unit that inputs a command signal related to travel of the vehicle body, and the left drive wheel. And a drive unit for independently rotating the right drive wheel, a rotation number detection unit for detecting the actual rotation number of the left drive wheel and the right drive wheel, the command signal, the left drive wheel and the right drive A vehicle that controls the drive unit based on the actual number of rotations of the wheel, a vehicle body angular velocity detection unit that detects a yaw angular velocity that is an angular velocity around the yaw axis of the vehicle body, and the vehicle body And a barycentric position detecting unit that detects the barycentric position of the total load including the occupant, and the control unit, based on the command signal, a target vehicle body angular speed at which the vehicle body rotates about the yaw axis, and Above Command value setting means for setting a target straight traveling speed at which the body goes straight, feedback correction means for correcting the target vehicle body angular speed based on a predetermined control law using a difference between the target vehicle body angular speed and the yaw angular speed, and Feedforward correction means for correcting the target vehicle body angular velocity based on the positional relationship between the left drive wheel and the right drive wheel and the position of the center of gravity, and the target vehicle body corrected by the feedback correction means and the feedforward correction means Target calculating means for calculating the target rotational speed of the left driving wheel and the right driving wheel based on the angular velocity and the target straight traveling speed, the target rotational speed of the left driving wheel and the right driving wheel, the left driving wheel, and the Drive control means for controlling the drive force of the drive unit based on the actual rotational speed of the right drive wheel.

  Of the above, the yaw angular velocity and the target vehicle body angular velocity are quantities having the same dimensions. In the present specification, clarification is achieved by using different terms depending on the detected yaw angular velocity and the target vehicle body angular velocity that is the control target. The yaw angular velocity may be paraphrased as the detected vehicle body angular velocity.

  Further, the center-of-gravity position detection unit includes a plurality of load detection units that detect a load value at which a plurality of wheels including at least the left drive wheel and the right drive wheel share the total load, and each of the load detection units includes You may have a gravity center position calculation means which calculates the gravity center position of at least one direction among the left-right direction and the front-back direction of the said vehicle body based on the detected load value.

  Further, the feedforward correction means includes a left / right distribution ratio of the total load distributed to the left driving wheel and the right driving wheel according to the position of the center of gravity, an axle of the left driving wheel and the right driving wheel, and the The target vehicle body angular velocity is corrected using at least one of the effective radius of the left driving wheel and the right driving wheel obtained from the longitudinal distance from the center of gravity position and the load values of the left driving wheel and the right driving wheel. It is preferable to do.

  Furthermore, a roll angle detection unit that detects a roll angle when the vehicle body rotates around a roll axis and tilts, and the feedforward correction unit uses the roll angle and the front-rear direction distance to detect the target vehicle body. It is preferable to correct the angular velocity.

  Furthermore, it is preferable that the feedforward correction means includes a value limiting unit that limits a correction amount for correcting the target vehicle body angular velocity.

  According to the present invention, the center of gravity position of the total load is detected, and the target vehicle body angular velocity is feedforward corrected based on the positional relationship between the left driving wheel and the right driving wheel and the center of gravity position, and finally the left driving wheel and the right driving It controls the driving force of the drive unit that independently rotates the wheels. Here, since the position of the center of gravity is detected and used for feedforward correction, it is possible to perform correction in consideration of the movement of the center of gravity caused by a change in the seating posture of the occupant. Therefore, compared with the feedforward correction that does not consider the change in the seating posture of the occupant using only the roll angle of Patent Document 1, the correction accuracy is improved while reducing the adjustment by an individual actual machine, and the one-way flow during cant traveling is reduced. Thus, it is possible to improve the straight traveling performance.

  Further, in the aspect in which the center-of-gravity position detection unit serves as the load detection unit and the center-of-gravity position calculation means, the center-of-gravity position can be calculated with high accuracy based on the load value of each wheel. Therefore, the effects of reducing the single flow and improving the straight traveling performance become remarkable.

  Further, in the aspect in which the feedforward correction means corrects the target vehicle body angular velocity using at least one of the left-right distribution ratio, the front-rear direction distance, and the effective radius of the left driving wheel and the right driving wheel, for each item to be used, Action occurs. That is, by using the right / left distribution ratio, the lateral movement of the center of gravity caused by the change in the seating posture of the occupant can be reflected in the correction control. Further, by using the distance in the front-rear direction, the movement in the front-rear direction of the gravity center position can be reflected in the correction control. Further, by using the effective radii of the left driving wheel and the right driving wheel, changes in the effective radius due to the weight of the occupant and the change in the left / right distribution ratio can be reflected in the correction control. These actions are exerted additively, and the effects of reducing the one-sided flow and improving the straight traveling performance become remarkable.

  Further, in the aspect in which the feedforward correction means corrects the target vehicle body angular velocity using the roll angle and the longitudinal distance, the change in the turning moment can be reflected in the correction control. Therefore, the correction for the right / left distribution ratio of the load and the correction for the change of the turning moment can be used together, and the effects of reducing the one-way flow and improving the straight traveling performance become even more remarkable.

  Further, in the aspect in which the feedforward correction means has a value limiting unit that limits the correction amount for correcting the target vehicle angular velocity, even if the position of the center of gravity changes sharply due to road surface undulation or a sudden change in the posture of the occupant The correction amount is limited. Therefore, there is no possibility that the behavior of the vehicle body changes suddenly, and the stability of the traveling control is improved.

1 is a rear view showing an overall configuration of an electric wheelchair that is a personal vehicle according to a first embodiment. It is a block diagram explaining the structure of the drive system and control system of an electric wheelchair. It is a control block diagram of the control part which performs driving control of an electric wheelchair. It is a detailed block diagram of the angular velocity correction part among the control parts which perform driving control of an electric wheelchair. It is the flowchart which showed the arithmetic processing flow of the traveling control of a control part. It is a top view explaining typically the method of calculating the right-and-left distribution ratio of the load which the left and right drive wheels share with an electric wheelchair. It is a block diagram explaining the structure of the drive system and control system of the electric wheelchair of 2nd Embodiment. It is a detailed block diagram of the angular velocity correction | amendment part among the control parts which perform driving control of the electric wheelchair of 2nd Embodiment. It is the rear view which illustrated the situation of the electric wheelchair which cant travels in the direction which crosses an inclined road surface. FIG. 10 is a plan view schematically illustrating a left-right distribution ratio of a total load and a turning moment of an electric wheelchair that cant travel as shown in FIG. 9. It is a top view explaining typically the right-and-left distribution ratio and the turning moment of the total load of the electric wheelchair which cant run while running wheelie.

  A personal vehicle according to a first embodiment of the present invention will be described with reference to FIGS. The personal vehicle of the first embodiment is an electric wheelchair 1, and first, the overall configuration will be described. FIG. 1 is a rear view showing an overall configuration of an electric wheelchair 1 which is a personal vehicle of the first embodiment. The electric wheelchair 1 includes a vehicle body 2, a left drive wheel 3L and a right drive wheel 3R, an operation unit 4, a left drive unit 5L and a right drive unit 5R, a left load sensor 81L, a right load sensor 81R, and the like.

  The vehicle body 2 has a symmetrical shape. The vehicle body 2 includes a left side portion 21L and a right side portion 21R, a seating portion 22A, a backrest portion 22B, a left armrest 23L and a right armrest 23R, a left footrest 24L and a right footrest 24R, and a left fall prevention bar 25L and a right fall prevention bar 25R. Become. The left side surface portion 21L and the right side surface portion 21R are arranged perpendicularly in parallel with each other, and are coupled by two coupling members 211 and 212 that intersect in an X shape. The seating portion 22A is disposed at a substantially intermediate height position between the left side surface portion 21L and the right side surface portion 21R, and extends substantially horizontally from the left side surface portion 21L to the right side surface portion 21R. The backrest portion 22B extends upward from the rear edge of the seating portion 22A and spans from the left side surface portion 21L to the right side surface portion 21R. On the back side of the backrest portion 22B, a battery 29 serving as a traveling power source and a control power source is divided into two parts.

  The left handle portion 27L and the right handle portion 27R are disposed so as to extend rearward from the upper end rear portion of the left side surface portion 21L and the right side surface portion 21R. The left armrest 23L and the right armrest 23R are disposed so as to project substantially horizontally from the outside near the upper side of the left side surface portion 21L and the right side surface portion 21R to the left and right sides. The left footrest 24L and the right footrest 24R are disposed so as to extend forward from the lower side of the left side surface portion 21L and the right side surface portion 21R.

  The left fall prevention bar 25L and the right fall prevention bar 25R are disposed so as to extend rearward from the lower ends of the left side surface portion 21L and the right side surface portion 21R. A left rear wheel 26L is provided at the rear end of the left fall prevention bar 25L, and a right rear wheel 26R is provided at the rear end of the right fall prevention bar 25R. The left driving wheel 3L and the right driving wheel 3R are provided on the lower rear side outside the left side surface portion 21L and the right side surface portion 21R. The axle of the left drive wheel 3L is rotatably supported by the left side surface portion 21L, and the axle of the right drive wheel 3R is rotatably supported by the right side surface portion 21R. The interval between the landing points of the left driving wheel 3L and the right driving wheel 3R is a tread T. A left front wheel 28L (see FIG. 6) and a right front wheel 28R (see FIG. 6) that are not visible in FIG. 1 are rotatably provided on the lower front side outside the left side surface portion 21L and the right side surface portion 21R.

  The left load sensor 81L (see FIG. 2) that is not visible in FIG. 1 is provided between the axle of the left drive wheel 3L and the left side surface portion 21L. The left load sensor 81L detects the left load FL shared by the left drive wheel 3L, and corresponds to a load detection unit of the present invention. Similarly, the right load sensor 81R (see FIG. 2) is provided between the axle of the right drive wheel 3R and the right side surface portion 21R. The right load sensor 81R detects the right load FR shared by the right drive wheel 3R, and corresponds to a load detection unit of the present invention.

  An operation unit 4 having a substantially rectangular parallelepiped shape is disposed in front of the upper surface of the right armrest 23R. The operation unit 4 has a joystick 41 protruding from the upper surface thereof. A substantially rectangular parallelepiped left drive unit 5L and right drive unit 5R are disposed at positions slightly lower than the seating portion 22A on the rear side of the left side surface portion 21L and the right side surface portion 21R. The left drive unit 5L faces the axle of the left drive wheel 3L, and the right drive unit 5L faces the axle of the right drive wheel 3R.

  The occupant can sit on the seating portion 22A and lean against the backrest portion 22B, and can get on the electric wheelchair 1 with his / her feet on the left armrest 23L and the right armrest 23R. Further, the occupant can operate the joystick 41 with the right hand placed on the right armrest 23R. The caregiver can move the electric wheelchair 1 by pushing the left handle portion 27L and the right handle portion 27R.

  When the occupant rides in a normal posture, the center of gravity G of the total load Ftot including the vehicle body 2 and the occupant connects the landing points of the left driving wheel 3L, the right driving wheel 3R, the left front wheel 28L, and the right front wheel 28R. Located inside the ellipse. In normal traveling of the electric wheelchair 1, the total load Ftot is shared by the left driving wheel 3L, the right driving wheel 3R, the left front wheel 28L, and the right front wheel 28R, and the left rear wheel 26L and the right rear wheel 26R are not landed. The left rear wheel 26L and the right rear wheel 26R land when the road surface is uneven or when the gravity center position G is extremely shifted backward to prevent the vehicle body 2 from falling backward. Regarding the wheel diameter, the effective radius Re of the left driving wheel 3L and the right driving wheel 3R is the largest, the effective radius of the left rear wheel 26L and the right rear wheel 26R is the smallest, and the effective radius of the left front wheel 28L and the right front wheel 28R is Intermediate size. The effective radii of the corresponding left and right wheels are treated as being equal to each other.

  Next, the structure of the drive system and control system of the electric wheelchair 1 will be described. FIG. 2 is a block diagram illustrating the configuration of the drive system and the control system of the electric wheelchair 1. As shown in the figure, the drive system and the control system are composed of an operation unit 4, a left drive unit 5L, and a right drive unit 5R. The left drive unit 5L is mainly related to the drive and control of the left drive wheel 3L, and the right drive unit 5L is mainly related to the drive and control of the right drive wheel 3R. The operation unit 4 has a man-machine interface function for receiving the command signal S1 from the occupant and displaying necessary information, has an arithmetic processing function for the command signal S1, and further operates the left drive unit 5L and the right drive unit 5R in a coordinated manner. It has a main control function.

  The operation unit 4 includes the joystick 41 and the main controller 42 described above. The joystick 41 tilts in an arbitrary direction by the operation of the occupant. The joystick 41 converts an occupant operation into a command signal S <b> 1 and inputs the command signal S <b> 1 to the operation control unit 43 of the main controller 42. The direction in which the joystick 41 tilts commands the traveling direction of the electric wheelchair 1, and the tilt angle commands the traveling speed. That is, the electric wheelchair 1 travels at a higher speed as the tilt angle is larger. The joystick 41 corresponds to an operation unit of the present invention that inputs a command signal S1 relating to the travel of the vehicle body 2.

  The main controller 42 includes an operation control unit 43, an operation communication unit 44, a switch 45, a display unit 46, and an operation power supply unit 47. The switch 45 is a part that is operated by an occupant to set a speed range. For example, the speed range can be regulated to different upper limit speeds in each speed range as the first to fifth speed ranges. Specifically, for example, when the tilt angle of the joystick 41 is maximized in the first speed range, the vehicle travels at 1 km / h, and when the tilt angle of the joystick 41 is maximized in the fifth speed range, the vehicle travels at 6 km / h. Can be set. The display unit 46 displays the set speed range, the storage status of the battery 29, and the like for the occupant. The information to be displayed is not limited to the above. For example, the current traveling speed may be displayed as a bar graph.

  The operation control unit 43 receives a command signal S1 from the joystick 41, receives a speed range setting signal from the switch 45, and instructs the display unit 46 to display contents. Further, the operation control unit 43 performs a calculation process on the command signal S1. The operation communication unit 44 connects the operation control unit 43 and another device so as to be capable of bidirectional communication so that information can be exchanged. The operation power supply unit 47 receives power supply from the battery 29, stabilizes the power supply voltage, and supplies power to each unit 43 to 46 in the main controller 42. As the main controller 42, for example, an electronic control device having a CPU, a memory, and an input / output unit and operating with software can be used.

  The left drive unit 5L includes a left motor 51L, a left rotation speed sensor 52L, and a left controller 53L. The output shaft of the left motor 51L is rotationally connected to the axle of the left drive wheel 3L, and rotationally drives the left drive wheel 3L. Although there is no special restriction | limiting in the kind of left motor 51L, It is preferable that it can rotate to both the normal rotation and reverse rotation. The left rotation speed sensor 52L is disposed in the vicinity of the axle of the left drive wheel 3L, detects the actual rotation speed NL of the left drive wheel 3L, converts it into a left rotation speed signal, and outputs it.

  The left controller 53L includes a left control unit 54L, a left communication unit 55L, a left angular velocity sensor 56L, a left motor drive unit 57L, and a left power supply unit 58L. The left angular velocity sensor 56L detects a yaw angular velocity ωY that is an angular velocity around the yaw axis of the vehicle body 2, converts it to a left angular velocity signal, and outputs it. For example, a gyro sensor can be used as the left angular velocity sensor 56L. When the yaw angular velocity ωY is a positive value, the vehicle body 2 is turning right, and when the yaw angular velocity ωY is a negative value, the vehicle body 2 is turning left. The left motor drive unit 57L adjusts the left drive voltage VL applied to the left motor 51L based on the left drive signal from the left control unit 54L. The left motor drive unit 57L converts the left drive current flowing through the left motor 51L into a left current signal and outputs the left current signal.

  The left control unit 54L receives a left rotation number signal from the left rotation number sensor 52L, receives a left angular velocity signal from the left angular velocity sensor 56L, and receives a left current signal from the left motor driving unit 57L. Furthermore, the left control unit 54L receives a left load signal corresponding to the left load FL from the left load sensor 81L. The left control unit 54L mainly performs arithmetic processing related to driving and control of the left drive wheel 3L, and commands a left drive signal to the left motor drive unit 57L.

  The left communication unit 55L connects the left control unit 54 and another device so as to be capable of bidirectional communication so that information can be exchanged. The left power supply unit 58L receives power supply from the battery 29, stabilizes the power supply voltage, supplies power to the units 54L to 57L in the left controller 53L, and further supplies the left drive voltage VL. As the left controller 53L, for example, an electronic control device having a CPU, a memory, and an input / output unit and operating by software can be used.

  The configuration of the right drive unit 5R is the same as that of the left drive unit 5L, and can be understood by replacing the left attached to the name with the right and the L attached to the reference with R. Briefly, the right drive unit 5R includes a right motor 51R, a right rotation speed sensor 52R, and a right controller 53R. The right controller 53R includes a right control unit 54R, a right communication unit 55R, a right angular velocity sensor 56R, a right motor drive unit 57R, and a right power supply unit 58R. Further, since the function of the right drive unit 5R is the same as that of the left drive unit 5L, description thereof is omitted.

  Here, since the left motor drive unit 57L and the right motor drive unit 57R can independently adjust the left and right drive voltages VL and VR, the left drive wheel 3L and the right drive wheel 3R are independently rotated. This corresponds to the drive unit of the present invention. The left rotation speed sensor 52L and the right rotation speed sensor 52R correspond to the rotation speed detection unit of the present invention.

  Further, the operation control unit 43, the left control unit 54L, and the right control unit 54R are connected to each other by the communication units 44, 55L, and 55R so as to be capable of bidirectional communication, and can exchange information. The three control units 43, 54L, and 54R cooperate to control the traveling of the electric wheelchair 1. Therefore, the operation control unit 43, the left control unit 54L, and the right control unit 54R control the drive unit based on the command signal S1 and the actual rotation speeds NL and NR of the left drive wheel 3L and the right drive wheel 3R. The control unit is configured. The configuration of the control unit is not limited to the above, and may be a configuration in which central control is performed by one controller, for example. Since there is no restriction on the function sharing of the three control units 43, 54L, and 54R, the following description will be made simply as the function of the control unit.

  The left angular velocity sensor 56L and the right angular velocity sensor 56R both detect the yaw angular velocity ωY of the vehicle body 2 and output the left angular velocity signal and the right angular velocity signal, and thus correspond to the vehicle angular velocity detection unit of the present invention. The left angular velocity signal and the right angular velocity signal are essentially equal but are considered to be different amounts, and the left control unit 54L can receive the left rotation number signal and the right control unit 54R can receive the right rotation number signal. Without being limited thereto, one of the left angular velocity sensor 56L and the right angular velocity sensor 56R can be used regularly, and the other can be reserved. Further, the yaw angular velocity ωY may be obtained by averaging the left angular velocity signal of the left angular velocity sensor 56L and the right angular velocity signal of the right angular velocity sensor 56R. Furthermore, it is possible to eliminate one of the left angular velocity sensor 56L and the right angular velocity sensor 56R.

  Next, a method for traveling control of the electric wheelchair 1 will be described. FIG. 3 is a control block diagram of a control unit that performs traveling control of the electric wheelchair 1. As shown in the figure, the control unit includes a target speed and angular velocity calculation unit 61 and a target output calculation unit 62. In addition, the target speed and angular velocity calculation unit 61 includes an angular velocity correction unit 63. The control unit receives the command signal S1 from the joystick 41 and uses the detected left load FL and right load FR as feedforward inputs. Further, the control unit uses the detected yaw angular velocity ωY of the vehicle body 2 and the detected actual rotational speeds NL and NR of the left and right drive wheels 3L and 3R as feedback inputs. The controller finally outputs the left drive voltage VL in the form of a left drive signal and outputs the right drive voltage VR in the form of a right drive signal.

  Based on the command signal S1, the target speed and angular velocity calculation unit 61 sets a target straight traveling speed V1 at which the vehicle body 2 travels straight and a target vehicle body angular speed ω1 at which the vehicle body 2 rotates about the yaw axis. When the tilt direction of the joystick 41 is in the range of 180 ° on the front side, the target straight traveling speed V1 is a positive value, and when the tilt direction is in the range of 180 ° on the rear side, the target straight travel speed V1 is a negative value. Further, when the tilt direction of the joystick 41 is in the range of 180 ° on the left side, the target vehicle body angular velocity ω1 is a positive value, and when the tilt direction is in the range of 180 ° on the right side, the target vehicle body angular velocity ω1 is a negative value. The function of setting the target straight traveling speed V1 and the target vehicle body angular speed ω1 corresponds to the command value setting means of the present invention.

  The angular velocity correction unit 63 performs feedforward and feedback correction calculations with the target vehicle angular velocity ω1, the yaw angular velocity ωY, the left load FL and the right load FR as inputs, and obtains a corrected target vehicle angular velocity ω2. The detailed internal configuration of the angular velocity correction unit 63 will be described later.

  The target output calculation unit 62 first calculates the target rotational speeds of the left and right drive wheels 3L and 3R based on the corrected target vehicle body angular velocity ω2 and the target straight traveling speed V1. This calculation function corresponds to the target calculation means of the present invention. Next, the target output calculator 62 calculates the left and right drive voltages VL and VR based on the target rotation speeds and the actual rotation speeds NL and NR of the left and right drive wheels 3L and 3R. The target output calculation unit 62 outputs the left drive voltage VL to the left motor drive unit 57L in the form of a left drive signal, and outputs the right drive voltage VR to the right motor drive unit 57R in the form of a right drive signal. As a result, the actual drive voltage applied to the left and right motors 51L and 51R is controlled. This control function corresponds to the drive control means of the present invention.

  Next, details of the angular velocity correction unit 63 will be described. FIG. 4 is a detailed block diagram of the angular velocity correction unit 63 in the control unit that performs traveling control of the electric wheelchair 1. The angular velocity correction unit 63 includes a feedback correction calculation unit 71, a load correction calculation unit 72, and an output calculation unit 73.

  The feedback correction calculation unit 71 performs proportional control. The feedback correction calculation unit 71 includes a subtractor 711, a difference limiting unit 712, and a proportional term multiplier 713. The subtractor 711 calculates a difference Δω between the target vehicle body angular velocity ω1 and the yaw angular velocity ωY. At this time, the yaw angular speed ωY is subtracted from the target vehicle body angular speed ω1 when the target straight traveling speed V1 is a positive value, and conversely, the target vehicle body angular speed ω1 is subtracted from the yaw angular speed ωY when the target straight traveling speed V1 is a negative value. To do. Next, the difference limiting unit 712 corrects the difference Δω to a limit value only when the difference Δω exceeds a predetermined limit value (there are two positive and negative values). The difference Δω after passing through the value limiting unit 712 is output to the proportional term multiplier 713. The proportional term multiplier 713 multiplies the difference Δω by a proportional term constant Kp to obtain a proportional term ωp, which is output to the output calculation unit 73. The feedback correction calculation unit 71 corresponds to the feedback correction means of the present invention.

The load correction calculation unit 72 includes a load term calculation unit 721, a change amount limiting unit 722, an absolute value limiting unit 723, and a load term multiplier 724. The load term calculator 721 obtains the load distribution ratio shared by the left and right drive wheels 3L, 3R, that is, the right / left distribution ratio RF by the following equation (1), and outputs it to the change amount limiting unit 722.
Left / right distribution ratio RF = (load of right drive wheel 3R) / (load of left drive wheel 3L)
= FR / FL ………………………………………………… (1)

  The change amount limiting unit 722 restricts the change amount to the limit change amount only when the change amount from the previous value of the left / right distribution ratio RF exceeds a predetermined limit change amount (there are two positive and negative values). The current value of the left / right distribution ratio RF is obtained. The absolute value limiting unit 723 corrects the left / right distribution ratio RF to the limit value only when the current value of the left / right distribution ratio RF exceeds a predetermined limit value (there are two positive and negative values). The load term multiplier 724 multiplies the left / right distribution ratio RF after passing through the variation limiting unit 722 and the absolute value limiting unit 723 by the load term constant KF to obtain a load term ωF, and outputs the load term ωF to the output calculation unit 73. The load correction calculation unit 72 corresponds to feedforward correction means of the present invention. Further, the change amount limiting unit 722 and the absolute value limiting unit 723 correspond to the value limiting unit of the present invention.

  The adder 731 of the output calculation unit 73 adds the proportional term ωp and the load term ωF to obtain a correction term ωadd. The computing unit 732 of the output computing unit 73 operates as an adder or subtracter. That is, at the time of forward movement in which the target straight traveling speed V1 is a positive value, the calculator 732 adds the correction term ωadd to the original target vehicle body angular speed ω1 to obtain the corrected target vehicle body angular speed ω2. Further, at the time of reverse travel where the target straight traveling speed V1 is a negative value, the calculator 732 subtracts the correction term ωadd from the original target vehicle body angular speed ω1 to obtain a corrected target vehicle body angular speed ω2. The corrected target vehicle body angular velocity ω2 is output to the target output calculation unit 62 as shown in FIG.

  Next, a calculation processing flow of travel control of the control unit will be described. FIG. 5 is a flowchart showing a calculation processing flow of travel control of the control unit. In step S1 of FIG. 5, the control unit reads the command signal S1 from the joystick 41 and detection signals of the left load FL, the right load FR, and the yaw angular velocity ωY. Next, the control unit calculates a yaw angular velocity ωY in step S2. Further, in step S3, the target straight speed V1 is set by the straight speed calculator 61, and the target vehicle angular speed ω1 is set by the angular speed calculator 62. In step S4, the feedback correction calculation unit 71 calculates the angular velocity difference Δω.

  In step S5, it is determined whether or not the difference Δω is greater than or equal to a certain value. If the difference Δω is less than a certain value, the calculation processing flow is immediately terminated. This means that the electric wheelchair 1 is running in a steady state and there is no need to change the left and right drive voltages VL and VR.

  If the difference Δω is greater than or equal to a certain value, the process proceeds to step S6, and the load term ωF is calculated by the load correction calculation unit 72. Next, in step S7, the corrected target vehicle angular velocity ω2 is calculated by the output calculation unit 73. Further, in step S8, the target output calculator 62 calculates the left and right target rotational speeds N1L and N1R. Next, in step S9, the target output calculator 62 calculates the left drive voltage VL and the right drive voltage VR. Thereby, the actual drive voltage applied to the left and right motors 51L and 51R from the left and right motor drive units 57L and 57R is controlled, and the electric wheelchair 1 travels.

Next, the operation and effect of the electric wheelchair 1 of the first embodiment configured as described above will be described. FIG. 6 is a plan view schematically illustrating a method of calculating the left / right distribution ratio RF of the load shared by the left and right drive wheels 3L, 3R in the electric wheelchair 1. FIG. In FIG. 6, a symbol in which a mark “X” is superimposed on a mark “◯” indicates a load (the same applies to FIGS. 10 and 11). FIG. 6 shows a state in which an occupant gets on the electric wheelchair 1 and the left driving wheel 3L, the right driving wheel 3R, the left front wheel 28L, and the right front wheel 28R have landed. The load FL shared by the left drive wheel 3L and the load FR shared by the right drive wheel 3R are detected. Based on these two quantities, the total load Ftot including the vehicle body 2 and the occupant is detected. Can be obtained by calculation. That is, the left side distance T1 between the center of gravity position G and the left driving wheel 3L and the right side distance T2 between the center of gravity position G and the right driving wheel 3R can be obtained by the following equations (2) and (3).
Left distance T1 = FR · T / (FL + FR) ………………………… （2）
Right distance T2 = FL ・ T / (FL + FR) ……………………………… (3)

Furthermore, since the left / right distribution ratio RF of the load is obtained by the inverse ratio of the left distance T1 and the right distance T2, it is expressed by the following equation (4).
Left / right distribution ratio RF = Left distance T1 / Right distance T2 (4)
Substituting Equation (2) and Equation (3) into Equation (4) naturally matches Equation (1).

  That is, in the first embodiment, the right / left distribution ratio RF can be directly calculated by the equation (1) without actually obtaining the left / right arrangement of the gravity center position G. However, in a mode in which the center-of-gravity position G is detected by means other than the left and right load sensors 81L and 81R, it is necessary to calculate the right / left distribution ratio RF using the equation (4). Therefore, the control unit indirectly uses the left distance T1 and the right distance T2 even if it does not explicitly calculate the left distance T1 and the right distance T2, and includes the center-of-gravity position calculating means of the present invention. Further, the combination of the control unit and the left and right load sensors 81L and 81R corresponds to the gravity center position detection unit of the present invention.

  In the electric wheelchair 1 of the first embodiment, the target vehicle body is detected using a function equivalent to detecting the center of gravity position G of the total load Ftot and based on the positional relationship between the left driving wheel 3L and the right driving wheel 3R and the center of gravity position G. The angular velocity ω1 is feedforward corrected, and finally the driving force (left and right drive voltages VL, VR) of the drive unit that rotationally drives the left drive wheel 3L and the right drive wheel 3R independently is controlled. Here, since feedforward correction is performed with a function equivalent to detecting the center of gravity position G, it is possible to perform correction in consideration of center of gravity movement caused by a change in the seating posture of the occupant. Therefore, compared with the feedforward correction which does not consider the change in the seating posture of the occupant using only the roll angle of Patent Document 1, the correction accuracy is improved, and the one-way flow at the time of cant traveling can be reduced and the straight traveling performance can be improved.

  Further, the center-of-gravity position detection unit is realized by the calculation functions of the left and right load sensors 81L and 81R and the control unit, and the center-of-gravity position G and the left-right distribution ratio RF are based on the load values FL and FR of the drive wheels 3L and 3R. Can be calculated with high accuracy. Then, the load correction calculation unit 72 that embodies the feedforward correction means corrects the target vehicle body angular velocity ω1 using the right / left distribution ratio RF. Therefore, the lateral movement of the gravity center position G caused by the change in the sitting posture of the occupant can be reflected in the correction control. As a result, the effects of reducing the single flow and improving the straight traveling performance become remarkable.

  Furthermore, the load correction calculation unit 72 includes a change amount limiting unit 722 and an absolute value limiting unit 723 that limit the correction amount for correcting the target vehicle body angular velocity ω1. For this reason, even if the gravity center position G changes abruptly due to road surface undulations or a sudden change in the posture of the occupant, the correction amount of the load term ωF is limited. Therefore, there is no possibility that the behavior of the vehicle body 2 changes suddenly, and the stability of the traveling control is improved.

  Next, regarding the electric wheelchair 1 of the second embodiment, points different from the first embodiment will be mainly described, and the same points will be denoted by the same reference numerals and description thereof will be omitted. FIG. 7 is a block diagram illustrating the configuration of the drive system and the control system of the electric wheelchair 1 according to the second embodiment. The overall configuration (see FIG. 1) of the electric wheelchair 1 of the second embodiment is the same as that of the first embodiment. As can be seen by comparing FIG. 7 and FIG. 2, in the second embodiment, four load sensors 82L, 82R, 83L, 83R and two roll angle sensors 59L, 59R are added.

  More specifically, a left front load sensor 82L is provided between the left front wheel 28L and the vehicle body 2, and a right front load sensor 82R is provided between the right front wheel 28R and the vehicle body 2. Further, a left rear load sensor 83L is provided between the left rear wheel 26L and the vehicle body 2, and a right rear load sensor 83R is provided between the right rear wheel 26 and the vehicle body 2. Each load sensor 82L, 82R, 83L, 83R detects a left front load FLf, a right front load FRf, a left rear load FLr, and a right rear load FRr shared by the wheels 28L, 28R, 26L, 26R. This corresponds to the load detection unit of the invention. Detection signals from the left front load sensor 82L and the left rear load sensor 83L are output to the left control unit 54L, and detection signals from the right front load sensor 82R and the right rear load sensor 83R are output to the right control unit 54R.

A left roll angle sensor 59L is provided inside the left controller 53L of the left drive unit 5L. The left roll angle sensor 59L detects the roll angle θ when the vehicle body 2 rotates and tilts around the roll axis, converts it into a left roll angle signal, and outputs it. Similarly, a right roll angle sensor 59R is provided inside the right controller 53R of the right drive unit 5R. The right roll angle sensor 59R also detects the roll angle θ when the vehicle body 2 rotates and tilts around the roll axis, converts it into a right roll angle signal, and outputs it. The left roll angle sensor 59L and the right roll angle sensor 59R correspond to the roll angle detection unit of the present invention.

  The left roll angle signal and the right roll angle signal are essentially the same but are considered to be different amounts, and the left control unit 54L can receive the left roll angle signal and the right control unit 54R can receive the right roll angle signal. Without being limited thereto, one of the left roll angle sensor 59L and the right roll angle sensor 59R can be used regularly, and the other can be used as a spare. Alternatively, the roll angle θ may be obtained by averaging the left roll angle signal of the left roll angle sensor 59 and the right roll angle signal of the right roll angle sensor 59R. Furthermore, one of the left roll angle sensor 59L and the right roll angle sensor 59R can be eliminated.

  As the left and right roll angle sensors 59L and 59R, for example, the acceleration sensor disclosed in Patent Document 1 can be used. This acceleration sensor employs a method of detecting an acting force and converting it to acceleration. Therefore, the acceleration sensor can determine the roll angle θ by detecting the direction of gravity.

  In the second embodiment, the configuration of the control block of the control unit that performs the traveling control of the electric wheelchair 1 is the same as that in FIG. 3, and the input items of the angular velocity correction unit 63A are added as compared with the first embodiment. That is, the angular velocity correction unit 63A of the second embodiment includes the above-described left front load FLf, right front load FRf, left rear load FLr, in addition to the yaw angular velocity ωY and the left load FL and right load FR of the first embodiment. The right rear load FRr and the roll angle θ described above are input.

  FIG. 8 is a detailed block diagram of the angular velocity correction unit 63A in the control unit that performs the traveling control of the electric wheelchair 1 of the second embodiment. The angular velocity correction unit 63 </ b> A includes a feedback correction calculation unit 71, a load correction calculation unit 75, a gravity center correction calculation unit 76, and an output calculation unit 77. The feedback correction calculation unit 71 has the same configuration as that of the first embodiment, and detailed description thereof is omitted. The proportional term multiplier 713 of the feedback correction calculation unit 71 outputs the proportional term ωp to the output calculation unit 77.

  The load correction calculation unit 75 receives the load of each wheel, that is, the left load FL, the right load FR, the left front load FLf, the right front load FRf, the left rear load FLr, and the right rear load FRr. The load correction calculation unit 75 includes a load & center-of-gravity calculation unit 751, a change amount limiting unit 752, an absolute value limiting unit 753, and a load term multiplier 754.

The load & center-of-gravity calculator 751 obtains the right / left distribution ratio RF by the following equation (5) and outputs it to the variation limiting unit 752.
Left / right distribution ratio RF = (right wheel load) / (left wheel load)
= (FR + FRf + FRr) / (FL + FLf + FLr) (5)

  The change amount limiting unit 752 limits the change amount to the limit change amount only when the change amount from the previous value of the left / right distribution ratio RF exceeds a predetermined limit change amount (there are two positive and negative values). The current value of the left / right distribution ratio RF is obtained. The absolute value limiter 753 corrects the left / right distribution ratio RF to the limit value only when the current value of the left / right distribution ratio RF exceeds a predetermined limit value (there are two positive and negative values). The load term multiplier 754 multiplies the right / left distribution ratio RF after passing through the variation limiting unit 752 and the absolute value limiting unit 753 by the load term constant KF to obtain a load term ωF, which is output to the output calculation unit 77.

The load & center-of-gravity calculator 751 obtains the total load Ftot by the following equation (6), obtains the longitudinal distance LG (LG3) by the following equation (8) or equation (12), and obtains the center-of-gravity correction calculator 76. Output to.
Total load Ftot = FL + FR + FLf + FRf + FLr + FRr (6)
The front-rear direction distance LG (LG3) means the distance by which the gravity center positions G2, G3 are shifted in the front-rear direction with respect to the axles of the left driving wheel 3L and the right driving wheel 3R (LG in FIG. 10 and FIG. 11). LG3).

The center-of-gravity correction calculation unit 76 includes a turning moment calculation unit 761, a change amount limiting unit 762, an absolute value limiting unit 763, and a barycentric term multiplier 764. The turning moment calculator 761 receives the roll angle θ, the total load Ftot, and the longitudinal distance LG (LG3). The turning moment calculation unit 761 obtains the turning moment M by the following equation (7) and outputs it to the change amount limiting unit 762. However, the total load Ftot has a dimension of force obtained by multiplying the total mass by a universal gravitational constant.
Turning moment M = LG ・ Ftot ・ sinθ …… (7)

  The change amount limiting unit 762 limits the change amount to the limit change amount and turns only when the change amount from the previous value of the turning moment M exceeds a predetermined limit change amount (with positive and negative values). Find the current value of moment M. The absolute value limiting unit 763 corrects the turning moment M to the limit value only when the current value of the turning moment M exceeds a predetermined limit value (there are two positive and negative values). The center-of-gravity term multiplier 764 multiplies the turning moment M after passing through the change amount limiting unit 762 and the absolute value limiting unit 763 by the center-of-gravity term constant KG, and outputs it to the output calculating unit 77.

  The output calculation unit 77 includes two adders 771 and 772 and a calculator 773. In the two adders 771 and 772, the gravity term ωG and the load term ωF are added in order to the proportional term ωp to calculate the correction term ωadd. The computing unit 773 operates as an adder or subtracter. That is, at the time of forward movement in which the target straight traveling speed V1 is a positive value, the calculator 773 adds the correction term ωadd to the original target vehicle body angular speed ω1 to obtain the corrected target vehicle body angular speed ω2. Further, at the time of reverse travel where the target straight traveling speed V1 is a negative value, the calculator 773 subtracts the correction term ωadd from the original target vehicle body angular speed ω1 to obtain a corrected target vehicle body angular speed ω2. The corrected target vehicle body angular velocity ω <b> 2 is output to the target output calculation unit 62.

  The load correction calculation unit 75 and the gravity center correction calculation unit 76 of the second embodiment correspond to the feedforward correction unit of the present invention. Further, the change amount limiting unit 752, the absolute value limiting unit 753, the change amount limiting unit 762, and the absolute value limiting unit 763 correspond to the value limiting unit of the present invention.

  Next, the operation of the electric wheelchair 1 according to the second embodiment configured as described above will be described. FIG. 9 is a rear view illustrating the situation of the electric wheelchair 1 that cant travel in the direction crossing the inclined road surface. FIG. 10 is a plan view schematically illustrating the left-right distribution ratio RF2 of the total load Ftot and the turning moment M of the electric wheelchair 1 that cant travel as shown in FIG. In FIG. 9, the inclined road surface of the roll angle θ is inclined upward, that is, a mountain side on the right side of the sheet, and inclined downward, that is, a valley side, on the left side of the sheet. The total load Ftot acting on the gravity center position G2 of the electric wheelchair 1 can be considered by being decomposed into a vertical component FV perpendicular to the inclined road surface and an inclined surface component FH directed downward on the inclined side. The inclined surface component FH is obtained by (Ftot · sin θ).

Here, as shown in FIG. 10, when the gravity center position G2 is shifted to the front side by the longitudinal distance LG with respect to the axle, the inclined surface component FH generates a turning moment M. The turning moment M changes substantially in proportion to the front-rear direction distance LG and is obtained by the above-described equation (7). Furthermore, the front-rear direction distance LG can be obtained by the following equation (8) using the four load values illustrated in FIG. 10, that is, the left load FL, the right load FR, the left front load FLf, and the right front load FRf. it can. However, the value of the wheel base (distance between the axes) B between the left and right drive wheels 3L, 3R and the left and right front wheels 28L, 28R is stored in advance in the control unit.
Longitudinal distance LG =
(FLf + FRf) · B / (FL + FR + FLf + FRf) (8)
Therefore, the traveling direction in which the electric wheelchair 1 moves forward due to the generation of the turning moment M tends to be directed to the valley side (lower tilt side) as indicated by the white arrow Q1 in FIG.

Further, the left distance T21 and the right distance T22 can be obtained from the following four formulas (9) and (10) from the four load values exemplified in FIG.
Left distance T21 =
(FR + FRf) · T / (FL + FR + FLf + FRf) (9)
Right distance T22 =
(FL + FLf) · T / (FL + FR + FLf + FRf) (10)

Furthermore, since the left / right distribution ratio RF2 of the load is obtained by the inverse ratio of the left distance T21 and the right distance T22, it can be obtained by the following equation (11).
Left / right distribution ratio RF2 = left distance T21 / right distance T22
= (FR + FRf) / (FL + FLf) (11)
Equation (11) is included in Equation (5).

Next, the operation when the wheelchair is run with the electric wheelchair 1 of the second embodiment will be described. FIG. 11 is a plan view schematically illustrating the left-right distribution ratio RF3 of the total load Ftot and the turning moment M of the electric wheelchair 1 that cant travel while traveling on a wheelie. The wheelie travel is a four-wheel travel mode in which the left front wheel 28L and the right front wheel 28R are landed instead of landing the left front wheel 28L and the right front wheel 28R. In FIG. 11, the electric wheelchair 1 is traveling on an inclined road surface having the same roll angle θ as in FIG. 9, and the same inclined surface component FH is generated with respect to the center of gravity position G3. However, the center-of-gravity position G3 is shifted rearward by the longitudinal distance LG3 with respect to the axle.
The front-rear direction distance LG3 is obtained by the following equation (12) using four load values exemplified in FIG. 11, that is, the left load FL, the right load FR, the left rear load FLr, and the right rear load FRr. it can. However, the value of the inter-axis distance A between the left and right drive wheels 3L and 3R and the left and right rear wheels 26L and 26R is stored in the control unit in advance.
Longitudinal distance LG3 =
(FLr + FRr) · A / (FL + FR + FLr + FRr) (12)
In the wheelie travel, the direction in which the center of gravity G3 shifts is the rear side opposite to the normal time, and the rotation direction of the turning moment M is also reversed. As a result, the traveling direction in which the electric wheelchair 1 moves forward tends to be directed to the mountain side (inclined upper side) as indicated by the white arrow Q2 in FIG.

Similar to the case of FIG. 10, the left-side distance T31 and the right-side distance T32 can be obtained by the following equations (13) and (14).
Left distance T31 =
(FR + FRr) · T / (FL + FR + FLr + FRr) (13)
Right distance T32 =
(FL + FLr) · T / (FL + FR + FLr + FRr) (14)

Furthermore, since the left-right distribution ratio RF3 of the load is obtained by the inverse ratio of the left-side distance T31 and the right-side distance T32, it can be obtained by the following equation (15).
Left / right distribution ratio RF3 = left distance T31 / right distance T32
= (FR + FRr) / (FL + FLr) (15)
Formula (15) is included in Formula (5).

  The load correction calculation unit 75 obtains the right / left distribution ratio RF (RF2, RF3) using the equation (5) and the included equations (11) and (15), and performs feedforward correction. That is, the control unit actually calculates the front-rear direction distance LG (LG3) and indirectly uses the left-side distances T21 and T31 and the right-side distances T22 and T32, and includes the center-of-gravity position calculation means of the present invention. Further, the combination of the control unit and the six load sensors 81L, 81R, 82L, 82R, 83L, 83R corresponds to the center-of-gravity position detection unit of the present invention.

  Further, in the second embodiment, the operation for obtaining the longitudinal distance LG (LG3) corresponds to the center-of-gravity position calculating means of the present invention. In addition, the center-of-gravity correction calculation unit 76 actually calculates the turning moment M using the formula (7) including the longitudinal distance LG (LG3) and performs feedforward correction. Here, the rotation direction of the turning moment M changes depending on the direction of inclination of the inclined road surface and the shift direction of the gravity center position G (G2, G3). On the other hand, if the sign of the roll angle θ and the sign of the front-rear direction distance LG (LG3) are taken into consideration, the arithmetic processing of the control unit can be made common. In other words, the sign of the roll angle θ is reversed between the upward slope road surface and the upward slope road surface, and the longitudinal distance LG is positive in FIG. 10, and the longitudinal distance LG3 is negative in FIG. As a result, it is not necessary to divide the calculation processing into cases.

  In the second embodiment, the following effects are produced in addition to the effects of the first embodiment. That is, in the electric wheelchair 1 of the second embodiment, the feedforward correction means corrects the target vehicle body angular velocity ω1 by using the roll angle θ and the longitudinal distance LG (LG3), and therefore the change in the turning moment M is reflected in the correction control. can do. Therefore, the correction for the left / right distribution ratio FR (FR2, FR3) of the load and the correction for the change of the turning moment M can be used in combination, and the effects of reducing the single flow and improving the straight traveling performance become even more remarkable.

  The personal vehicle of the present invention is not limited to the first and second embodiments described above, and various modifications and improvements that can be made by those skilled in the art without departing from the gist of the present invention. Needless to say, it can be implemented in the form. For example, the left and right angular velocity sensors 56L and 56R may be omitted as the vehicle angular velocity detection unit, and the yaw angular velocity may be calculated from the actual rotational speeds NL and NR detected by the left and right rotational speed sensors 52L and 52R. Further, for example, in the left rotation number calculation unit 64, the right rotation number calculation unit 65, the left driving force calculation unit 66, and the right driving force calculation unit 67 of each embodiment, the axle angular velocity having the same dimension is used instead of the rotation number. The same traveling control function can be provided even if the calculation processing is performed. In this case, the target axle angular speeds are used in place of the target rotational speeds N1L and N1R of the left and right drive wheels 3L and 3R, and the actual rotational speeds NL and NR are converted into axle angular speeds.

  Furthermore, using the left load FL and the right load FR detected in the first and second embodiments, a change in the effective radius Re of the left and right drive wheels 3L, 3R can be calculated and used for feedforward correction. . Further, a control law other than proportional control can be used in the feedback correction calculation unit 71 of the angular velocity correction units 63 and 63A. Furthermore, the left rear load sensor 83L and the right rear load sensor 83R may be omitted without considering wheelie travel in the second embodiment.

  In addition to the electric wheelchair 1 described in the embodiment, the present invention can be widely used for personal vehicles represented by personal vehicles and the like.

1: Electric wheelchair (personal vehicle)
2: Vehicle body 26L: Left rear wheel 26R: Right rear wheel 29: Battery 28L: Left front wheel 28R: Right front wheel 3L: Left drive wheel 3R: Right drive wheel 4: Operation unit 41: Joystick (operation unit)
42: main controller 43: operation control unit 44: operation communication unit 5L: left drive unit 51L: left motor 52L: left rotation speed sensor 53L: left controller 54L: left control unit 55L: left communication unit 56L: left angular velocity sensor 57L: Left motor drive unit 59L: Left roll angle sensor 5R: Right drive unit 51R: Right motor 52R: Right rotation speed sensor 53R: Right controller 54R: Right control unit 55R: Right communication unit 56R: Right angular velocity sensor 57R: Right motor drive unit 59R: Right roll angle sensor 61: Target velocity and angular velocity calculation unit 62: Target output calculation unit 63, 63A: Angular velocity correction unit 71: Feedback correction calculation unit 72: Load correction calculation unit 73: Output calculation unit 75: Load correction calculation unit 76: Center of gravity correction calculation unit 77: Output calculation unit 81L: Left load sensor 81R: Right load Heavy sensor 82L: Left front load sensor 82R: Right front load sensor 83L: Left rear load sensor 83R: Right rear load sensor S1: Command signal V1: Target straight speed ω1: Target vehicle body angular velocity ωY: Yaw angular velocity θ: Roll angle ω2: After correction Target vehicle body angular velocity NL, NR: actual rotation speed VL, VR: left and right drive voltage (drive force)
FL, FR, FLf, FRf, FLr, FRr: wheel load Ftot: total load RF, RF2, RF3: left / right distribution ratio LG, LG3: longitudinal distance M: turning moment

Claims (5)

A vehicle body, left drive wheels and right drive wheels provided on the left and right sides of the vehicle body, an operation unit for inputting a command signal relating to travel of the vehicle body, and the left drive wheel and the right drive wheel are independently rotated. A drive unit, a rotation number detection unit that detects the actual rotation number of the left drive wheel and the right drive wheel, and the drive unit based on the command signal and the actual rotation number of the left drive wheel and the right drive wheel. A personal vehicle comprising a control unit for controlling,
A vehicle body angular velocity detection unit that detects a yaw angular velocity that is an angular velocity around the yaw axis of the vehicle body, and a gravity center position detection unit that detects a gravity center position of a total load including the vehicle body and an occupant,
The controller is
Based on the command signal, command value setting means for setting a target vehicle body angular speed at which the vehicle body rotates around the yaw axis, and a target straight traveling speed at which the vehicle body goes straight,
Feedback correction means for correcting the target vehicle body angular velocity based on a predetermined control law using a difference between the target vehicle body angular velocity and the yaw angular velocity;
Feedforward correction means for correcting the target vehicle body angular velocity based on a positional relationship between the left driving wheel and the right driving wheel and the position of the center of gravity;
Target calculating means for calculating the target rotational speed of the left driving wheel and the right driving wheel based on the target vehicle body angular velocity corrected by the feedback correcting means and the feed forward correcting means and the target straight traveling speed;
And a drive control means for controlling the drive force of the drive unit based on the target rotation speed of the left drive wheel and the right drive wheel and the actual rotation speed of the left drive wheel and the right drive wheel. The barycentric position detector is
A plurality of load detectors that respectively detect a load value at which a plurality of wheels including at least the left driving wheel and the right driving wheel share the total load;
2. The personal vehicle according to claim 1, further comprising: a center-of-gravity position calculating unit that calculates a center-of-gravity position in at least one of a left-right direction and a front-rear direction of the vehicle body based on a load value detected by each of the load detection units.   The feedforward correction means includes a left / right distribution ratio of the total load distributed to the left driving wheel and the right driving wheel according to the center of gravity position, an axle of the left driving wheel and the right driving wheel, and the center of gravity position. The target vehicle body angular velocity is corrected using at least one of an effective radius of the left driving wheel and the right driving wheel obtained from a distance in the front-rear direction and load values of the left driving wheel and the right driving wheel. Item 3. The personal vehicle according to Item 1 or 2. A roll angle detection unit for detecting a roll angle when the vehicle body rotates and tilts around a roll axis;
The personal vehicle according to claim 3, wherein the feedforward correction unit corrects the target vehicle body angular velocity using the roll angle and the longitudinal distance.   The personal vehicle according to any one of claims 1 to 4, wherein the feedforward correction means includes a value limiting unit that limits a correction amount for correcting the target vehicle body angular velocity.

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