JPH0573139A - Controller for self-traveling truck - Google Patents

Abstract

PURPOSE:To obtain the device for enabling safe and secure travel smoothly with a little secular change and vibrations inexpensively by complementing the lack of spatial resolution for a detection system with the hourly resolution of a control system not to be affected by the dirt of a floor, etc. CONSTITUTION:This device is equipped with the inexpensive low-resolution detection system arranging detectors at inequal intervals, reader holding lateral acceleration and lateral speed previously optimized to the resolution of the detection system, and control system to control a driving system held by the reader. Namely, detectors 1 are installed toward a floor 4 on the four sides of a car body 2, the car body 2 is equipped with three wheels 3, the floor 4 is equipped with a guide tape 5, and the position is detected by the detectors 1 provided forward and backward to the advancing direction of the car body 2. Then, the induced control of the truck is executed along the guide tape 5 provided on the floor 4. Thus, even when the inexpensive and low-resolution detection system is used, the truck can be smoothly and safely controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is suitable for a self-propelled carriage that mainly conveys a conveyed object, particularly a self-propelled carriage that is used for conveying a precision product or the like which is sensitive to vibration such as semiconductor manufacturing. The present invention relates to a control device for a self-propelled carriage that can realize safe and reliable traveling control using an inexpensive low-resolution detection device.

[0002]

2. Description of the Related Art A conventional apparatus is, for example, Japanese Patent Publication No. 54-32.
As described in Japanese Patent Publication No. 117, a large number of light receiving elements are arranged on a line orthogonal to the guide tape, and when adjacent light receiving elements are simultaneously turned on, an intermediate value is taken to improve the spatial resolution. As described in Japanese Laid-Open Patent Publication No. -100581, two light receiving elements are installed near the end of the guiding tape, and the difference in signal intensity between the left and right light receiving elements is evaluated by an analog amount. Of which the spatial resolution is improved by analog-weighted addition evaluation of the light receiving amounts of a plurality of light receiving elements as described in JP-A-63-118810, and JP-A-59-32009. There is a device using a detection element having an extremely high spatial resolution such as a one-dimensional image pickup element as described in (1).

[0003]

In the case of the first prior art described above, the resolution was increased as compared with a simple arrangement of light receiving elements, but basically the on / off control could not perform a smooth operation. In the case of the second conventional technique, the spatial resolution was increased by using the received light amount which is an analog amount. However, if only the evaluation of the received light amount is used, the dirt on the reflection tape is different between left and right, or there is a pattern on the floor. Control error occurs and the light receiving range of the element cannot be widened, so derailment is easy. In the third conventional technique, the light receiving range is widened by using the light receiving amount of a large number of light receiving elements as compared with the second conventional technique, but since the light receiving amount is not evaluated, the change in the color of the reflective tape / floor is prevented. The error increases. In the case of the fourth conventional technique, the generation of vibration can be avoided because the resolution is extremely high, but a large-sized imaging lens system or a dedicated optical system is used by using an expensive one-dimensional image sensor and a dedicated high frequency drive circuit. Since it was necessary, it was expensive and required a large installation space. Especially for mobiles, the internal volume is severely limited, and the reduction of installation space is significant.

The object of the present invention is to make up for the drawbacks of the prior art described above, it is inexpensive and requires a small installation space, and does not affect the control system if the reflectance of the floor surface and the guiding tape is within the allowable range, and An object of the present invention is to provide a control device for a self-propelled carriage that travels smoothly with less secular change, with less vibration.

[0005]

In order to achieve the above object, in the present invention, the lack of the spatial resolution of the detection system is compensated by the time resolution of the control system which is not affected by dirt on the floor.

In order to reduce the cost and to save the installation space, the optical system and the drive circuit are simplified and downsized by using a plurality of single light receiving elements as compared with the case of using the one-dimensional image pickup element.

In order to avoid a situation in which the steering amount changes due to a change in the color of the floor surface, a slight reflection on the reflection-inducing tape and the floor surface, and to avoid adjustments peculiar to the analog detection system and readjustment due to aging, The amount of light received by the device was evaluated on and off without analog evaluation.

In order to realize smooth and less vibration control, the centripetal movement speed of the bogie is determined from the section passage time of the state quantity without increasing the spatial resolution of the detection system itself. Since the time measuring device is inexpensive and can be used stably, it is less likely to change due to disturbance as compared with the case of evaluating the light amount of the light receiving element.

In order to realize safe and reliable control, directly
The time integration of the signal value is not used in the speed correction term, and the section target speed is approached with a constant acceleration. Since the time integration of the signal value is not used as the speed correction term, there is no fear that the centripetal speed will diverge even when the section transit time of the curved traveling path changes.

[0010]

By using a plurality of single light-receiving elements, a low-resolution digital detection device is formed, which is inexpensive and requires a small installation space. In addition, the light receiving amount of the light receiving element is not evaluated in an analog manner, but is evaluated on and off, thereby avoiding the situation where the steering amount is changed due to a change in the color of the floor surface, a slight dirt on the reflection guide tape and the floor surface. The difficulties associated with system-specific adjustment and the need for readjustment due to changes over time are reduced.

By setting the centripetal target velocities in the plurality of detection resolution sections to values that gradually decrease toward the center of all sections, the moving direction of the carriage is surely directed to the center near the center of all sections, and It is possible to stop without causing an overshoot that passes through the central section, and it is possible to prevent the bogie from entering the uncontrollable area.

The acceleration in each of the detection resolution sections is calculated from the centripetal target velocity of the detection resolution section adjacent to the outer side of the acceleration within the time when the acceleration passes through the detection resolution section.
By determining the acceleration that can be decelerated to the above-mentioned centripetal target speed, while preventing the occurrence of vibration due to sudden acceleration and sudden deceleration,
Acceleration / deceleration can be reliably performed within the detection resolution section.

Further, the widths of a plurality of detection system resolution intervals are
By narrowing the setting as it gets closer to the center of all sections, the detection system resolution near the center of all sections is increased without narrowing the controllable sensing area, and the amount of meandering in the minimum resolution area inevitable for digital control is reduced. it can. At the same time, by making the acceleration in the outermost section constant and widening the width of the outer section, the maximum acceleration in the worst condition does not show an extremely large value, and it is not necessary to increase the power of the actuator more than necessary. ..

The detection device is composed of a plurality of on / off detection systems arranged on a straight line, and a tape having a reflectance / reflection angle distribution or a color different from the surroundings is attached to a floor or ceiling surface, which is used as a guide tape. By configuring a self-propelled carriage that detects and controls its position by the detection device, it is possible to realize a self-propelled carriage that makes the most of the advantages of the control device and the control method.

Further, the installation interval of the on / off detection system is set to be slightly narrower than the width of the guide tape on the left and right on the same center line as the fixed position of the guide tape, particularly in the innermost detection section. Since it is possible to set a large interval between the on-off detection systems in the inner section, it becomes easy to set the width of the above-mentioned detection system resolution section to be narrower toward the center of all sections.

Separately from this, in the vicinity of the innermost detection section, the installation intervals of the on / off detection system are set to be slightly smaller than 1/2 of the width of the guiding tape on the center line of the fixed position of the guiding tape and on the left and right sides sandwiching the center line. The same advantage can be realized by arranging widely.

Further, by equipping the front and rear of the bogie with the detection device, forward and backward movements are facilitated, and further, the detection resolution section is divided into two components of lateral deviation y and angular deviation θ of the bogie to control the arithmetic unit. By making this easy and using a traveling mechanism capable of traveling in all directions, it is possible to avoid the repeated overshooting that is typical of conventional steering type self-propelled carriages.

Then, by inputting the vehicle traveling speed v at that time to the arithmetic unit and correcting the changing speed of the lateral deviation composed of v · sin θ, the interference of the lateral deviation y and the angular deviation θ can be avoided. In particular, by using a traveling mechanism capable of traveling in all directions, the direction of the carriage and the traveling direction can be determined separately, so this correction can be performed independently.

Since the above control calculation is relatively simple,
By configuring the arithmetic unit from an analog hardware arithmetic circuit including an adder circuit and an integrating circuit, the response speed including the control system can be improved. On the other hand, when the detection device has a particularly low resolution, it does not require a high calculation speed, so that the calculation device is a central calculation device, a fixed storage device,
By comprising the hardware such as the variable storage device and the digital / analog conversion device and the software stored in the storage device, it is possible to improve the reproducibility by eliminating the need for fine adjustment peculiar to the analog hardware arithmetic circuit.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing the arrangement of the detection device and the like of the present invention. The detection device 1 is installed on four sides of the vehicle body 2 facing the floor surface 4. Further, the vehicle body 2 is provided with wheels 3 at three locations. Here, a guiding tape 5 is provided on the floor surface 4, and the position of the guiding tape 5 is detected by the front and rear detection devices 1 in the traveling direction of the vehicle body 2.

The wheels 3 used in this embodiment are
Is a multi-row roller on the installation surface to eliminate the ground resistance in the lateral direction, and by the vector composition of the rotation speed of each wheel,
The three degrees of freedom of x, y, and θ are independently generated in the vehicle body 2.

FIG. 2 shows the detector 1, the floor 4, and the guide tape 5.
Shows the positional relationship when the vehicle is traveling correctly. A guide tape 5 having a width of 50 mm is attached to the floor surface 4. On the other hand, the detection device 1 is composed of three detection systems 101a to 101c fixed via spacers 102 at intervals of 30 mm. Detection systems 101a-10
1c is a light emitting diode, a lens, a phototransistor,
It is composed of an amplifier circuit, and the binarized output signal 1
03a to 103c are taken out.

Here, since the guiding tape 5 contains fine beads, the spatial distribution characteristic of the reflected light is special, and the reflected light is distributed in the range close to the optical axis of the incident light.
Therefore, as shown in FIG. 3, the apparent reflectance can be largely changed from that of a general floor surface by obliquely taking the incident angle and the reflection angle. A general surface has a spatial distribution characteristic of reflected light in the middle of a diffuse reflection surface and a specular reflection surface, and the ratio of reflected light returning to the original to oblique incident light is low.

The width of the guide tape 5 shown above is 50 mm,
From the relationship of 30 mm distance between the detection systems 101a to 101c,
The relationship between the lateral displacement amount y of the vehicle body 2 and the output signals 103a to 103c is as follows. The body 2 is 5 mm on the guide tape 5.
When facing each other with an error of less than, the output signals 103a to 103c are sequentially off, on, and off. Output signal 103a to 10 when the lateral displacement y is 5 mm or more and less than 25 mm
3c is off, on, and on in that order. Furthermore, the lateral shift y
Is between 25 mm and less than 55 mm, the output signals 103a to 103c are OFF, OFF, and ON in that order. This relationship is the same except that the output signal 103a and the output signal 103c are exchanged even when the deviation occurs in the opposite direction and the value of the lateral deviation y becomes negative.

FIG. 4 is a graph showing this relationship by representing the reading Y of the detection device 1 by the central value of the detection resolution section. As can be seen from this figure, the width of the detection resolution section is narrower in the central section and wider in the outer section. Here, FIG. 13 shows a table of the centripetal target velocities and accelerations for each detection resolution section.
This acceleration is set to a value such that the speed that has entered the current section at the target speed of the outer section can be decelerated to the target speed of the current section in the time that passes through the current section. In the case of the innermost section, the value is set so that it can be stopped exactly at the center of the section. In the present embodiment, since the detection resolution section in the central portion is narrowed, the error in the convergence position of control can be reduced despite the low average resolution, and further the acceleration in the inner section is reduced, Although the risk of derailment is low, the acceleration near the control convergence position could be reduced.

FIG. 5 is a flowchart showing the method of controlling the lateral deviation direction. The current output speed Vy in the horizontal direction can use the previous output result. Next, the centripetal target velocity and acceleration are determined by the current reading Y of the detection device 1. Here, if the lateral movement speed Vy is not the centripetal target speed, acceleration / deceleration is performed at a predetermined acceleration to bring it closer to the centripetal target speed.

FIG. 6 shows the state of convergence during straight running when the control is started at several points at the lateral moving speed Vy = 0 according to the above method. Similarly, FIG. 7 shows a convergence state during straight running when control is started from a point of 10 mm at several lateral movement speeds Vy. As can be seen from these figures, a sudden change in speed does not occur, and smooth control can be realized without causing vibration. Further, when the vehicle enters the central section, if it has a certain lateral speed, it can be stopped near the center of the section, so that it takes a long time until the next acceleration is generated. This is a function that cannot be realized by the conventional on / off control.

Up to this point, the follow-up running with respect to the guiding tape 5 is possible, but as shown in FIG. 8, when the entire vehicle body 2 has an angle deviation θ with respect to the guiding tape 5, a term for correcting the angle deviation θ. is necessary. The relationship between the angle deviation θ and the readings yf and yb of the front and rear detection devices 1 has a relationship with the distance between the front and rear detection devices 1 and the arc tangent. Further, when the detection device 1 has an offset with respect to the vehicle body 2, the angular deviation θ also indicates the lateral deviation Y. FIG. 14 shows the relationship between the readings yf and yb of the front and rear detectors 1 and the lateral shift Y and angular shift θ in this embodiment. Ideally, it is preferable to evaluate the angle deviation θ as well as the lateral deviation Y. In the present embodiment, since the interval between the front and rear detection devices 1 is sufficiently wide, the resolution of the angle deviation θ is sufficiently high, and even if the angular velocity is Vω = θ [rad / sec], there is little problem, and therefore compensation is simply performed.

In the present embodiment, the longitudinal velocity and the lateral velocity are independently controlled, so that the lateral deviation correction is not directly related to the longitudinal velocity Vx. However, as shown in FIG. 6, when the entire vehicle body 2 has an angle deviation θ with respect to the guiding tape 5, the coordinate system of the vehicle body 2 and the coordinate system of the floor 4 are different, so that the traveling speed V to the front is reduced.
A moving speed Vy ′ in the lateral direction is generated by x. This relationship is Vy ′ = Vx · sin θ. To cancel this component, the lateral velocity component of -Vy 'is compensated. The forward speed Vx may be a normal acceleration / deceleration control according to the bogie traveling diagram.

The number of rotations of each wheel 3 is determined from Vx, Vy, and Vω determined as described above, and the servo motor for driving each wheel 3 is driven. Here, the point to be noted is that the control method up to this point does not relate to the positive or negative of the forward speed Vx.
That is, the same control method may be used even when the vehicle moves backward. Further, the same control may be performed during traverse, but since the detection device 1 is switched from the front-rear one to the left-right one and the evaluation of the angular deviation θ depends on the interval of the detection device 1, the same as in FIG. Prepare a separate table.

FIG. 9 is a block diagram showing the overall structure of this embodiment. The central processing circuit 601 is a fixed storage circuit 60.
2 reads data from the detection device 1 via the input device 604 according to the program stored in the fixed storage circuit 6
02. Each coefficient Vx, Vy, Vω of the traveling speed of the vehicle body 2 required on the variable storage circuit 603 using the coefficient table stored in 02.
And output circuit 605 to the servo motor 302.
Specify the rotation speed via. The servo motor 302 drives the wheels 301 via the speed reducer 303. A pulse generator 304 and a brake device 305 are attached to the servomotor 302, and the signal of the pulse generator 304 is referred to from the central processing circuit 601 via the coefficient circuit 606 and used for calculation of the traveling distance. .. The brake circuit 304 is driven by the central processing circuit 601 through the output circuit 605 after instructing the servo motor 302 to rotate at 0 in order to prevent the servo from drifting and to reliably stop when the vehicle is stopped.

FIG. 10 shows a perspective view of a manufacturing line in which the self-propelled carriage of the above embodiment provided with the transfer device 7 and the object-carrying base 8 is used as a carrier device. According to this embodiment,
Since a self-propelled carriage having less traversing vibration can be obtained at low cost, a line in which various manufacturing apparatuses 9a to 9c are arranged can be easily constructed.

Although one embodiment of the present invention has been described above, the present invention can be implemented with a configuration other than the above.

Although the wheels having a special structure are used in the above-described embodiment, even when steering is performed by changing the direction of the steered wheels using the normal wheels, the lateral acceleration is read as the steering angle. it can.

In the above embodiment, the guide tape having special optical characteristics was used, but a normal white tape, a metal tape or the like may be used depending on the condition of the floor surface. In this case, the angles of the detection systems 101a to 101c with respect to the floor surface are set to a right angle, or the illuminating device and the detection element are arranged symmetrically with respect to the plane including the normal line of the floor. Further, when the illuminating device and the colored tape are used, the influence of ambient light can be reduced by providing a color filter in front of the detection element. In this case, since an inexpensive guide tape can be used, there is an effect of cost reduction.

Further, an eddy current sensor,
It is also possible to use a sensor that detects the physical properties of a proximity object such as a capacitance sensor. In the case of an eddy current sensor, install a metal plate on the floor and use it as an induction target. In this case, the difference in conductivity between the floor surface and the guide target can be detected, and this can be separated and detected as ON / OFF of the sensor. In this case, there is an advantage that it is less likely to be affected by dirt on the floor surface as compared with the optical sensor.

Furthermore, it is also possible to set a guide target by changing the shape of the floor surface. That is, the detection device is configured by using a distance sensor such as an ultrasonic sensor, an eddy current sensor, or an electrostatic capacitance sensor, and detects a certain level of unevenness on the floor surface. This is effective when the physical properties of the floor surface and the guidance target cannot be largely changed, for example, when the floor surface is a perforated material such as metal grating. In the case of perforated materials, the guide target should have a shape protruding from the floor so that it is not affected by the holes.

Similarly, when the floor surface is made of non-ferrous metal, the detecting device is an electromagnetic field detecting element such as a hall element or a coil, and the induction target is a magnetic tape or a rubber magnet or the like or a wire to which a high frequency is applied. It can also be implemented by configuring. In this case, there is an advantage that the floor surface is not provided with large unevenness and is not easily affected by contamination and abrasion.

In the first embodiment, the width of the guiding tape 5 is 50 mm and the pitch between the detection systems 101a to 101c is 3 mm.
Although it is set to 0 mm, other configurations are also possible. For example,
When the number of detection systems is an even number, FIG. 11 shows a detection device in which the pitch of the innermost detection system 101 is 42 mm, which is slightly narrower than that of the guiding tape 5, and the pitch of the outer detection system 101 is 96 mm. In this case, the values of the output signals 103a to 103d from the detection systems 101a to 101d are, in order, off / on / on / off up to a lateral displacement of 4 mm, off / off / on / off from 4 mm to 23 mm, and from 23 mm to 46 mm. OFF / OFF / ON / ON, OFF / OFF / OFF / ON from 46mm to 73mm. This relationship holds in reverse order even when the direction of deviation is opposite. The above relationship is summarized in a graph and shown in FIG. Even in the arrangement of the detection system 101, the position resolution is finer in the inner section. In this embodiment, since the outer section is large, there is an advantage that the detection range can be expanded without deteriorating the detection resolution.

[0040]

According to the present invention, even if an inexpensive, small-sized, low-resolution detector is used, it can be used to convey an object such as a wafer that is not susceptible to vibration in the semiconductor manufacturing process, and it is smooth and has little vibration. In addition, it is possible to realize a self-propelled bogie with safe and reliable control with little change over time.

[Brief description of drawings]

FIG. 1 is a plan view showing an arrangement of a detection device and the like.

FIG. 2 is an elevational view showing the arrangement of a detection device and the like.

FIG. 3 is a side view showing the arrangement of detection devices and the like.

FIG. 4 is a graph showing the relationship between the lateral displacement of the carriage and the reading of the detection device.

FIG. 5 is a flowchart showing a method of controlling a lateral deviation direction.

FIG. 6 is a graph showing the convergence of control in straight running.

FIG. 7 is a graph showing a control convergence state under conditions different from those in FIG.

FIG. 8 is a plan view showing a case where the vehicle body has an angle deviation with respect to the guiding tape.

FIG. 9 is a block diagram showing an overall configuration.

FIG. 10 is a perspective view of a manufacturing line using the present invention.

FIG. 11 is an elevational view showing another arrangement of the detection device.

FIG. 12 is a graph showing the relationship between the lateral displacement of the carriage and the reading of the detection device in another arrangement.

FIG. 13 is a table showing a centripetal target velocity / acceleration in a detection resolution section.

FIG. 14 is a table showing the relationship between readings by the front and rear detection devices and lateral deviation / angle deviation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Detection device 2 Vehicle body 3 Wheel 4 Floor 5 Guidance tape 6 Control device 7 Transfer device 8 Transferred goods 9 Manufacturing device

Claims (14)

[Claims] 1. A self-propelled carriage control device for performing follow-up control using a low-resolution digital detection device in which a plurality of on-off detection means are arranged, wherein each centripetal target velocity in a plurality of detection resolution sections. Is set to a value that gradually decreases toward the center of the entire section, and the acceleration in each of the detection resolution sections, from the centripetal target velocity of the detection resolution section adjacent to the outer side, within the time that passes through the detection resolution section, A control device for a self-propelled carriage, comprising: a calculation device that calculates an acceleration that can be decelerated to the centripetal target speed, and that calculates the speed and the acceleration; and an output device that outputs a calculation result by the calculation device. 2. The method according to claim 1, wherein the widths of the plurality of centripetal system resolution sections are set to be narrower toward the center of all sections, so that the controllable sensing area is not narrowed and the vicinity of the center of all sections is set. The control device for a self-propelled carriage, characterized in that the detection system resolution is increased and the acceleration in the outer section is set without increasing more than necessary. 3. The acceleration value in the detection system resolution section according to claim 1 or 2, wherein the acceleration value in the detection system resolution section is set to be smaller toward the center of all sections, so that excessive acceleration vibration is generated near the normal center. A control device for a self-propelled carriage, characterized in that the acceleration in the outer section is set to a sufficiently large value without inviting. 4. The method according to claim 1, wherein
The detecting device is composed of a plurality of optical detecting means arranged on a straight line, and the position of the guiding tape in which a tape whose reflectance / reflection angle distribution or color is different from the surroundings is attached to the floor or ceiling surface is detected. By detecting with the device,
A control device for a self-propelled carriage that is characterized by performing guided travel. 5. The method according to any one of claims 1 to 3,
The detecting device is composed of a plurality of detecting means for detecting a difference in material such as eddy current type arranged on a straight line, and a thin metal guide tape is provided on the floor, and the material of the guide tape and the floor A control device for a self-propelled carriage, characterized in that guide traveling is performed by detecting the position of the detection device based on a difference in material. 6. The method according to any one of claims 1 to 3,
The detection device is composed of a plurality of distance detection means arranged on a straight line, a plate-shaped projection is provided on the floor as a guide target,
A control device for a self-propelled carriage, characterized in that the position of the guide target is detected by the detecting device based on the difference in distance between the guide target and the floor surface to perform guide travel. 7. The method according to any one of claims 1 to 3,
A plurality of Hall devices, in which the detection device is arranged on a straight line,
It is composed of an electromagnetic detecting means such as a coil, and a magnetic tape, a magnetized strip-shaped induction tape such as a rubber magnet or an induction wire to which a high frequency is applied is provided on the floor surface, and the position of this induction tape or the induction wire is detected by the detection device. A control device for a self-propelled carriage, characterized by performing guided traveling by doing so. 8. The method according to claim 1, wherein
A control device for a self-propelled carriage, characterized in that an installation interval near the center of the detecting means is arranged on the left and right on the same center line as the fixed position of the guide tape, slightly narrower than the width of the guide tape. 9. The method according to claim 1, wherein
The detecting means is installed at an interval of 1 cm of the width of the guide tape on the center line of the guide tape at a fixed position and on the left and right sides of the center line.
A control device for a self-propelled carriage characterized by being placed slightly wider than / 2. 10. The arithmetic device according to claim 1, wherein the detection device is provided in front of and behind a bogie, and a detection resolution section is divided into two components of lateral deviation y and angular deviation θ of the bogie, and a control device. A control device for a self-propelled carriage having a traveling mechanism capable of traveling in all directions. 11. The control apparatus for a self-propelled vehicle according to claim 10, wherein the vehicle traveling speed v at that time is input to the arithmetic unit to correct a lateral deviation change rate of v · sin θ. 12. A control device for a self-propelled carriage according to claim 1, wherein the arithmetic device is composed of a hardware arithmetic circuit including an adder circuit, an integrating circuit, and the like. 13. The hardware according to claim 1, wherein the arithmetic unit is a hardware including a central arithmetic unit, a fixed memory device, a variable memory device, a digital / analog converter, and the like, and software stored in the memory device. A control device for a self-propelled carriage, which is configured by 14. A production line using the self-propelled carriage according to any one of claims 1 to 13.