Travelling object control system utilizing power control

A control system for automatic operation of travelling objects through a power supply system without using any signal communication systems. Either a DC power source or three-phase AC power source is utilized as a power source. With the system employing a DC power source, three trolley wires are installed, one a negative and two positive. Each of the positive wires is divided and insulated into sections of a predetermined length; the positive feeding trolley wires in each section is always supplied with the DC power, and the power to the other positive feeding trolley wire is switched on and off depending on the movement of travelling objects. Each travelling object is supplied with power by the three trolley wires has a DC motor, and when one of the positive wires has no voltage, this is detected and the braking is effected. The travelling object entering a station is automatically decelerated and stopped. When employing a three-phase AC power source, four trolley wires are installed, of which one is a neutral trolley wire and the remaining three trolley wires are with phases of AC power. Each of these three AC feeding trolley wires is divided and insulated into sections of a predetermined length, one of the three trolley wires is always supplied with the phase power, and power to the other two is switched on and off responsive to movement of the travelling objects, which travelling objects are equipped with an induction motor having star connected field coils and as power to the two AC feeding trolley wires is switched off, the unbalance current in the field coil flows to the neutral trolley wire causing braking.

BACKGROUND OF THE INVENTION 
The present invention relates to an improved block control system for 
travelling objects utilizing power control, and more particularly the 
invention relates to an improved block control system so designed that the 
automatic operation of vehicles is effected without resorting to controls 
by conventional or specially designed communication and signal systems but 
by simply through the power control of a feeder circuit which supplies 
power to the vehicle. 
The systems of automatic vehicle operation which have heretofore been put 
to practical use are generally of the type in which the automatic 
operation of vehicles is accomplished by supplying to the vehicles 
operation signals from an operation control equipment through vehicle 
operation controlling signal circuits which are provided in addition to 
the power feeding circuit. Thus, this type of automatic vehicle operation 
system requires, in addition to the power equipment system for vehicles, 
automatic operation control circuits, signal communication equipment, 
operation controlling equipment, etc., thus requiring huge equipment costs 
and much labor and time for maintenance and administration of these 
equipments, and moreover in the event that the automatic vehicle operation 
is rendered inoperative due to breakdown of vehicles or control systems 
etc., much time is needed for the restoration and thus it is very 
expensive to maintain continuously the fully automatic vehicle operation. 
Further, in the case of a loop line used as an urban railway for 
intermediate transit vehicles, it is still difficult to incorporate the 
conventional automatic vehicle operation system and realize its full 
practical use due to the huge equipment cost and much labors required for 
ensuring the required reliability. 
SUMMARY OF THE INVENTION 
With a view to overcoming the deficiencies and disadvantages of the prior 
art automatic operation of travelling objects employing a signal 
communication equipment, operation control equipment, etc., the present 
invention provides a control system of travelling objects which is 
designed to accomplish the automatic operation of travelling objects, 
e.g., electric cars only through the power control of a feeder circuit 
which supplies driving power to the travelling objects. 
It is therefore an object of the present invention to provide a control 
system for travelling objects which controls travelling objects only 
through the power control of DC constant voltage feeding or three-phase AC 
feeding. 
It is another object of the invention to provide a control system for 
controlling travelling objects through power control, including a feeder 
circuit in which a section controller is provided in each of the block 
sections, in such a manner that no voltage is applied to the trolley wire 
of the block section following, in the direction of movement of travelling 
objects, the section where a travelling object is present. 
It is still another object of the invention to provide a control system for 
controlling travelling objects through power control, including a feeder 
circuit in which is provided in each of the block sections a section 
controller which is capable of controlling in such a manner that no 
voltage is applied to the trolley wire of the block section following, in 
the direction of movement of travelling objects, the section where a 
travelling object is present, and at the same time the trolley wire of the 
block section following the no-voltage section is supplied with power at a 
lower voltage to slow down the travelling object which is present therein. 
It is still another object of the invention to provide a control system for 
controlling travelling objects through power control wherein each of the 
travelling objects includes a motor circuit employing a DC motor as a 
driving source whereby the dynamic braking is accomplished when a 
travelling object enter a no-voltage trolley wire section, and the 
travelling object is caused to proceed at reduced speed upon entering a 
lower voltage trolley wire section. 
It is still another object of the invention to provide a control system for 
controlling the operation of travelling objects through power control 
which is designed to automatically control travelling objects through 
power control of three-phase AC feeding by utilizing various advantages 
and features of a three-phase induction motor used as the driving source 
of each travelling object. 
It is still another object of the invention to provide a control system for 
controlling travelling object through power control wherein the 
three-phase AC feeding is controlled in such a manner that the dynamic 
braking is effected by utilizing the unbalanced field current produced in 
the three-phase induction motor of a travelling object in response to the 
removal of the voltage on the two trolley wires of the section following, 
in the direction of movement of travelling objects, the section where the 
travelling object is present. 
It is still another object of the invention to provide a control system for 
controlling travelling objects through power control wherein the phase 
current flowing to the neutral trolley wire in response to the entry of a 
travelling object into a no-voltage trolley wire section, is utilized to 
energize an electromagnet which in turn effects the magnetic braking in 
cooperation with a magnetic plate or electrically conductive plate. 
It is still another object of the invention to provide a control system for 
controlling the operation of travelling objects through power control 
which is capable of stopping a travelling object at the desired position 
by utilizing magnetic belt means adapted to effect the synchronous 
deceleration of a travelling object by utilizing the magnetic force 
produced between the magnetic belt means and the magnet means on the 
travelling object. 
The above and other objects, features and advantages of the present 
invention will be fully understood by considering the following detailed 
description taken in conjunction with the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring to FIG. 1, the construction of the feeder circuit used in one 
embodiment will be described first. A positive feeder line 10 is installed 
along a track, and connected to the positive feeder line 10 is an outgoing 
line from a DC constant voltage substation 12 which receives a three-phase 
AC power and accomplishes constant voltage feeding. First and second 
trolley wires 14 and 16 are installed along the track, and the first and 
second trolley wires 14 and 16 are provided with suitable sectioning 
devices, e.g., air sections 18, 20, 22, 24, 26, 28, 30 and 32 which are 
arranged at intervals of a predetermined block section, thus dividing the 
trolley wires 14 and 16 into trolley wire sections 34, 36, 38, 40, 42 and 
44, 46, 48, 50 and 52 which define a plurality of block sections. In this 
embodiment, the first trolley wire 14 is a trolley wire which always 
supplies at a constant voltage vehicle loads, e.g., the field systems of 
vehicle motors, and the second trolley wire 16 is one which is subjected 
to feeding control by the switching on and off of the constant voltage to 
supply at the constant voltage the armature coils of the vehicle motors. 
To provide this feeding control, section controllers 54, 56, 58 and 60, one 
for each block section, are provided between the positive feeder line 10 
and the first and second trolley wires 14 and 16. Taking the section 
controller 54 as an example, the positive feeder line 10 is connected to 
the trolley wire 34 by a branch line 62, and a branch line 64 connects the 
positive feeder line 10 to the trolley wire 46. In other words, assuming 
that the direction of movement of travelling oblect shown by an arrow 65 
corresponds to the up-line and the opposit direction corresponds to the 
down-line, with the air sections 18 and 26 providing bounds, the branch 
line 62 is connected to the up-line side trolley wire 34 and the branch 
line 64 is connected to the down-line side trolley wire 46. A current 
relay coil 66 is inserted and connected in the branch line 62, and the 
current relay coil 66 is so designed that the coil is energized when the 
feeder current flows from the trolley wire 34 to the armature coil of the 
motor of a travelling object, while the coil is deenergized when there is 
no flow of the feeder current. However, the trolley wire 34 is so arranged 
that the DC constant voltage from the positive feeder line 10 is always 
applied to the trolley wire 34 irrespective of the presence or absence of 
a travelling object. On the other hand, normally closed contacts 74 
operated by the current relay coil 66 are inserted and connected in the 
branch line 64. The normally closed contacts 74 are arranged so that when 
the current relay coil 66 is deenergized they are closed to apply the 
constant voltage from the positive feeder line 10 to the trolley wire 46, 
whereas when the current relay coil 66 is energized they are opened to 
apply no voltage to the trolley wire 46. In the absence of current the 
contacts 74 are opened so that current is not produced at the contacts, 
and the contact life is maintained. 
In the other section controllers 56, 58 and 60, the similar circuit 
connections as in the section controller 54 have current relay coils 68, 
70 and 72 and normally closed contacts 76, 78 and 80 which are adapted to 
be operated by the former. 
Next, the motor circuits of travelling objects 82 and 82' whose operation 
is to be controlled by the above-described feeder system, will be 
described with reference to the travelling object 82. 
The travelling object 82 employs a DC motor as its driving power source, 
and the DC motor is represented by a field coil 84 constituting the stator 
and an armature coil 86 constituting the rotor. The travelling object 82 
includes three current collectors consisting of a current collector 88 for 
collecting the current from the first trolley wire 14, current collector 
90 for collecting the current from the second trolley wire 16 and current 
collector 92 for a negative feeder line 17 employing the rail or trolley 
wire. The field coil 84 of the DC motor is connected between the current 
collectors 88 and 92 by connecting lines 83 and 85, and the armature coil 
86 is connected between the current collectors 90 and 92 by connecting 
lines 87 and 89. Since the section controller 56 always applies the 
constant voltage to the trolley wire 36, the field coil 84 is always 
subjected to the constant voltage feeding and the resulting feeding 
current flows in the coil. Consequently, the current relay coil 68 of the 
section controller 56 is energized so that the normally closed contacts 76 
are opened and no voltage is applied to the trolley wire 48. 
Normally open contacts 94 operated by a voltage relay coil 96 are connected 
in series with the armature coil 86 of the travelling object 82, and the 
normally open contacts 94 are opened and closed by the voltage relay coil 
96. The voltage relay coil 96 responds by detecting the speed 
electromotive force (e) of the armature coil 86. In other words, when the 
speed of the travelling object 82 reaches a predetermined speed, the 
voltage relay coil 96 is energized by the speed electromotive force (e) 
generated at that speed, so that the normally open contacts 94 are closed 
and the constant voltage from the trolley wire 46 is supplied to the 
armature coil 86, thus causing the travelling object to come into a 
constant speed operation on the constant voltage power supply from the 
positive feeder line 10. 
The connecting lines 83 and 87 are relatively connected with each other 
through normally open contacts 98 operated by a voltage relay coil 102 and 
a resistor 100, and the normally open contacts 98 are opened and closed by 
the voltage relay coil 102. The voltage relay coil 102 is deenergized when 
no voltage is applied to the second trolley wire 16, and it is energized 
in response to the application of the voltage to the second trolley wire 
16. In the illustration, the voltage is applied to the trolley wire 46 in 
response to the closing of the normally closed contacts 74 in the section 
controller 54, so that the voltage relay coil 102 is energized and the 
contacts 98 are closed. The resistor 100 provides a voltage drop so that a 
lower voltage is applied to the armature coil 86 until the normally open 
contacts 94 are closed, that is, until the speed of the travelling object 
exceeds the predetermined value. 
Extended from the contacts 98 side of the resistor 100 is connecting line 
108 connecting in series normally closed contacts 104 operated by the 
voltage relay coil 102 and a resistor 106. When the voltage relay coil 102 
is deenergized, the normally closed contacts 104 are closed so that a 
closed loop comprising the armature coil 86, the resistor 100, the 
contacts 104 and the resistor 106 is formed, and the speed electromotive 
force (e) of the armature coil 86 is dissipated by the resistors 100 and 
106, thus accomplishing the dynamic braking. This dynamic braking is 
effected when the second trolley wire 16 is switched to the no-voltage 
condition during the running of the travelling object 82. A diode 110 in 
the connecting line 87 is provided to block reverse current. 
The above-described motor circuit of a travelling object is identical with 
that of the following travelling object 82' whose component parts are 
designated by the same reference numerals but with a prime. 
With the construction described above, the operation of the embodiment 
shown in FIG. 1 is as follows. 
Assume now that the travelling object 82 departs from the section between 
the section controller 54 and 56, and no other travelling object is 
present in the preceding section of the section controller 54. Under these 
conditions, no feeding current is flowing in the current relay coil 66 of 
the section controller 54, so that the current relay coil 66 is not 
energized and the contacts 74 are closed, thus supplying the constant 
voltage current from the DC constant voltage substation 12 to the trolley 
wire 46. 
The starting of the travelling object 82 is effected by suitable means 
provided independently of the feeder system shown in FIG. 1, that is, a 
separate normally open switch (not shown) is inserted in the branch line 
64 so as to be remotely turned on or alternately a normally open switch 
(not shown) is inserted in the armature coil 86 of the travelling object 
82 so as to be remotely turned on. When the constant voltage feeding to 
the trolley wire 46 is initiated in this way, the voltage relay coil 102 
is first energized by the constant voltage feeding voltage on the armature 
side of the trolley wire 46, thus closing the contacts 98 and opening the 
contacts 104 as shown in FIG. 1. Consequently, the armature coil 86 
receives the current from the connecting line 83 through the current 
limiting resistor 100 and the travelling object 82 is started. 
When the speed of the travelling object increases so that the speed 
electromotive force (e) of the armature coil 86 reaches a prescribed value 
which may for example be greater than about half the speed electromotive 
force produced by the feeding voltage during the cruising speed operation, 
the voltage relay coil 96 is energized and the contacts 94 are closed. 
Consequently, the armature coil 86 receives through the trolley wire 46 
the normal constant voltage feeding current collected by the current 
collector 90. Thus, by suitably designing the current limiting resistor 
100 and the operating voltage of the potential relay coil 96 by the speed 
electromotive force (e), the operations of a travelling object in any 
block section ranging from the starting to the point at which the 
travelling object comes into a cruising speed operation can be smoothly 
effected only through the power control. 
Next, with the travelling object 82 being present at rest or running in the 
section between the section controllers 54 and 56 in FIG. 1, the operation 
of the following travelling object 82' which occurs when it enters the 
immediately following section between the section controllers 56 and 58, 
will now be described. 
When the travelling objects 82' is entering, the constant voltage from the 
positive feeder line 10 is being applied to the trolley wire 38 through 
the branch line of the section controller 58. However, no voltage is being 
applied to the trolley wire 48. The reason is that the feeding current to 
the travelling object 82 flows to the current relay coil 68 of the section 
controller 56 so that the current relay coil 68 is energized and the 
contacts 76 are opened by the energization of the current relay coil 68. 
Consequently, when the travelling object 82' passes the air sections 22 and 
30 and enters the section of the trolley wires 38 and 48, a voltage relay 
coil 102' is deenergized by detecting the nonexistence of voltage on the 
trolley wire 48, so that contacts 98' are opened and contacts 104' are 
closed. The closing of the contacts 104' results in a closed loop 
comprising an armature coil 86', resistor 100', contacts 104' and resistor 
106', so that the speed electromotive force (e) of the armature coil 86' 
is dissipated by the resistors 100' and 106' as the load and the dynamic 
braking of the travelling object 82' is effected, thus decelerating and if 
this condition continues the travelling object 82' comes to stop. 
When the preceding travelling object 82 passes the section controllers 54 
and 56 and moves into the preceding section while the travelling object 
82' is being braked and decelerated or after the travelling object 82' has 
been stopped, the current relay coil 68 of the section controller 56 is 
deenergized and the contacts 76 are closed, thus applying the constant 
voltage to the trolley wire 48. In response to the application of the 
voltage to the trolley wire 48, the voltage relay coil 102' of the 
travelling object 82' is energized and the contacts 104' are opened. 
Consequently, the dynamic braking is released so that if the travelling 
object 82' is at rest, it is started and accelerated into the cruising 
speed operation, whereas if the travelling object 82' is at the 
deceleration operation it is accelerated and brought into the cruising 
speed operation. 
It will thus be seen that in accordance with the travelling object control 
system according to the invention, in response to the movement of a 
travelling object, no voltage is applied to one of the trolley wires for 
the block section following that section where the travelling object is 
present, thus decelerating or stopping the following travelling object and 
thereby accomplishing the block control of a plurality of successively 
moving travelling objects only through the power control. 
Referring now to FIG. 2, there is illustrated another embodiment of the 
travelling object control system through power control, in which a slow 
speed section is provided to succeed a deceleration and stopping section 
provided in the rear of a preceding travelling object to thereby improve 
the operating safety of the following travelling object which is 
automatically operated in accordance with the movement of the preceding 
travelling object. 
While the travelling object control system shown in FIG. 1 is well suited 
for controlling the operation of travelling objects operated at low speeds 
by virtue of the fact that the following travelling object is rapidly 
decelerated by the dynamic braking upon entering the block section to 
which no power is supplied and that the dynamic braking is released and 
the following travelling object is accelerated by the constant voltage 
feeding as soon as the preceding travelling object passes through the 
section just preceding the section where the following travelling object 
is present, this control system is insufficient for controlling travelling 
objects operated at high speeds. In other words, where the running speed 
of travelling objects is high or the weight of travelling objects is 
large, it is necessary to take into consideration the fact that there is 
the danger of failing to stop the following travelling object within the 
deceleration and stopping section and thus giving a feeling of the 
following travelling object to proceed into the section occupied by the 
preceding travelling object and collide therewith from behind and that 
particularly when the preceding travelling object is stopped suddenly due 
to an accident or the like there is the danger of the following travelling 
object colliding with the preceding travelling object from behind. 
These deficiencies are overcome by the control system shown in FIG. 2. The 
control system of FIG. 2 differs from the embodiment of FIG. 1 in that 
resistors 112, 114, 115 and 116 are respectively connected in series with 
the normally closed contacts 74, 76, 78 and 80 of section controllers 154, 
156, 158 and 160, that normally open contacts 118, 120, 122 and 124 are 
respectively connected in parallel with the resistors 112, 114, 115 and 
116 and that voltage relay coils 126, 128, 130 and 132 are provided for 
respectively opening and closing the normally open contacts 118, 120, 122 
and 124. The remaining feeder circuit and travelling object motor circuits 
are the same as in FIG. 1 and are designated by the same numerals. 
Taking the case of the section controller 154, the resistor 112 inserted in 
the branch line 64 and connected in series with the normally closed 
contacts 74 serves as a voltage dropping resistor so that when the feeding 
current by the constant voltage feeding is supplied to the trolley wire 46 
from the positive feeder line 10 in response to the closing of the 
contacts 74, the resistor 112 produces a voltage drop to reduce the 
feeding voltage of the trolley wire 46 to a lower voltage. Thus, in 
response to the voltage drop by the resistor 112, the load current to the 
armature coil of a travelling object is decreased and thus the speed of 
the travelling object is controlled at the desired slow speed. The value 
of the resistor 112 is determined suitably in accordance with the desired 
slow speed of travelling objects. 
The normally open contacts 118 connected in parallel with the resistor 112 
are so designed that when they are closed in response to the energization 
of the voltage relay coil 126, the DC constant voltage from the positive 
feeder line 10 is directly applied to the trolley wire 46. When the 
voltage relay coil 126 is deenergized, the contacts 118 are opened and the 
low voltage feeding for slow speed operation is effected through the 
resistor 112. The voltage relay coil 126 is connected between the trolley 
wire 44 of the preceding section separated by the air section 26 and the 
negative feeder line 17 which is disposed opposite to it as shown by the 
arrows, so that when either the constant voltage feeding current or low 
voltage feeding current is supplied to the trolley wire 44, the voltage 
relay coil 126 is energized and the contact 118 is closed, whereas when no 
voltage is applied to the trolley wire 44, the voltage relay coil 126 is 
deenergized and the contacts 118 are opened. In the illustrated 
conditions, the constant voltage is applied to the trolley wire 44 so that 
the potential relay coil 126 is energized and the contacts 118 are closed. 
The above-described circuit connections of the section controller 154 are 
identical with those of the remaining section controllers 156, 158 and 
160. 
In the following discussion of the operation of the control system shown in 
FIG. 2, let it be assumed that no other travelling objects are present in 
at least two preceding block sections in the direction of the movement of 
the travelling object 82 indicated by the arrow 65. Consequently, the 
current relay coil 66 of the section controller 154 is deenergized thus 
closing the contacts 74 and at same time the potential relay coil 126 is 
energized by the voltage applied to the trolley wire 44 thus closing the 
contacts 118. As a result, the DC constant voltage is applied from the 
positive feeder line 10 to the trolley wire 46 and also the DC constant 
voltage is applied to the trolley wire 36 through the branch line from the 
section controller 156, thus supplying the constant voltage feeding 
current to the travelling object 82 and thereby bringing it into the 
cruising speed operation. 
In this condition, let consider the section immediately following the 
section occupied by the travelling object 82, namely, the section located 
between the section controllers 156 and 158. The current relay coil 68 of 
the section controller 156 is energized by the feeding current supplied to 
the travelling object 82 and the contacts 76 are opened. With the contacts 
76 now open, no voltage is applied to the trolley wire 48 so that when a 
travelling object enters the section of the trolley wires 38 and 48, the 
dynamic braking of the travelling object is effected and it is even 
stopped, if necessary. Although the contacts 120 are being closed by the 
energization of the voltage relay coil 128 in the section controller 156, 
the contacts 76 are open thus applying no voltage to the trolley wire 48. 
On the other hand, considering the section controller 158, the trolley wire 
38 is occupied by no travelling object so that the current relay coil 70 
is deenergized and the contacts 78 are closed. Also, since no voltage is 
applied to the trolley wire 48 so that the voltage relay coil 130 is 
deenergized and the contacts 122 are opened, the DC constant voltage is 
applied to the trolley wire 50 from the positive feeder line 10 through 
the contacts 78 and the resistor 115. Also the DC constant voltage is 
applied to the trolley wire 40 from the positive feeder line 10 through 
the current relay coil 72 of the section controller 160. 
When the following travelling object 82' proceeds to the trolley wires 40 
and 50 as shown in the Figure, a voltage drop is caused across the 
resistor 115 of the controller 158 by the feeding current flowing from the 
trolley wire 50 to an armature coil 86' of the travelling object 82', so 
that the applied voltage to the trolley wire 50 is reduced to the 
predetermined low voltage. As a result, the travelling object 82' is 
decelerated to the speed determined by the value of the resistor 115. In 
other words, the power control is accomplished in which the section 
between the section controllers 158 and 160 or the section which is next 
but one to the preceding section occupied by the travelling object 82 is 
turned into a slow speed section. 
With the circuit construction described above, the control system of the 
invention for controlling the operation of travelling objects through the 
power control is so designed that without providing any conventional 
signal system but using only power control circuitry, not only travelling 
objects can be controlled to decelerate, but also the section following 
the braking and stopping section can be turned into a slow speed section, 
thus preventing sudden deceleration of travelling objects, ensuring 
improved riding confortability, preventing the application of the voltage 
to the section preceding the slow speed section to thereby positively stop 
the following travelling object even in the event of sudden stopping of 
the preceding travelling object, reducing the occurrence of breakdown of 
travelling objects due to rapid acceleration and deceleration and 
increasing the life of travelling objects. Moreover, the privision of the 
slow speed section has the effect of positively stopping a travelling 
object within the block section without increasing the length of the block 
sections or mounting any specially designed brake system on travelling 
objects. 
Referring now to FIG. 3, there is illustrated still another embodiment of 
the control system of this invention for controlling the operation of 
travelling objects through the power control, which is designed to 
accomplish the automatic control of travelling objects having induction 
motors in the motor circuit only through the power control by three-phase 
AC feeding control. 
In the Figure, a feeder circuit includes, installed along a track, 
three-phase AC feeder lines 200, 202 and 204, AC feeding trolley wires 
206, 208 and 210 and a neutral trolley wire 212. The trolley wires 206, 
208 and 210 are respectively electrically divided and insulated by 
suitable sectioning devices, e.g., air gaps 214, 216 . . . , 230 into 
sections each thereof constituting a predetermined block section. Section 
controllers 232, 234 and 236 are provided for the respective block 
sections. The section controllers 232, 234 and 236 connect the feeder 
lines 200, 202 and 204 to the trolley wires 206, 208 and 210. Taking the 
section controller 232 as an example, a current relay coil 268 is inserted 
and connected in a branch line 262 which in turn connects the feeder line 
200 to a sectionalized trolley wire 238, and normally closed contacts 270 
for two circuits which are operated by the current relay coil 268, are 
inserted and connected in branch lines 264 and 266 which connect the 
feeder lines 202 and 204 to sectionalized trolley wires 248 and 256. When 
the feeding current flows in the trolley wire 238 of the preceding block 
section, the current relay coil 268 is energized and the contacts 270 are 
opened. With the contacts 270 open, the voltage is no longer applied to 
the following block section trolley wires 248 and 256. The same circuit 
connections as the above-described section controller 232 are used for the 
other section controllers 234 and 236. 
Next, the motor circuit of a travelling object 300 will be described as an 
example of the travelling object motor circuits. The motor circuit 
includes current collectors 302, 304, 306 and 308 for collecting the 
current from the trolley wires 206, 208 and 210 and the neutral trolley 
wire 212, respectively. Current relay coils 316, 318 and 320 are 
respectively inserted and connected between the current collectors 302, 
304 and 306 and field coils 310, 312 and 314 which are respectively 
connected to the current collectors 302, 304 and 306 and adapted to rotate 
a rotor 315 of the three-phase induction motor, and each of the current 
relay coils is so designed that each coil is energized by the voltage 
applied from the trolley wire, while the coil is deenergized when no 
voltage is applied thereto from the trolley wire. The current relay coil 
316 has its normally closed contacts 322 inserted in the branch line 
coming out from the current collector side and leading to the current 
collector 308 through a resistor 324, and the current relay coils 318 and 
320 have their normally closed contacts 326 and 328 respectively inserted 
in the branch lines respectively coming out from the field coil side of 
the current relay coils 318 and 320 and leading to the current collector 
308 through resistors 330 and 332, respectively. 
When no voltage is applied to the trolley wires 208 and 210, respectively, 
the current relay coils 318 and 320 are deenergized so that their contacts 
326 and 328 are closed and the resistors 330 and 332 are inserted as the 
loads of the field coils 312 and 314, thus effecting the dynamic braking. 
The resistor 324 serves as a protective resistor so that when the field 
coil 310 is broken, the resistor 324 maintains the flow of the feeding 
current from the trolley wire 206 which is always supplied with the power. 
In other words, when the field coil 310 is broken, the current relay coil 
316 is deenergized and the contacts 322 are closed. Consequently, the 
resistor 324 is inserted thus flowing the feeding current which will 
normally be supplied from the trolley wire 206 by the presence of a 
travelling object and thereby allowing the energization of the current 
relay coil of the section controller. For this purpose, the AC impedance 
of the resistor 324 must be made equal to that of the field coil 310. 
The induction motor mounted on the travelling object 300 should most 
preferably be a three-phase induction motor having field coils connected 
in a star configuration. A common connecting point or neutral point 334 of 
the star-connected field coils 310, 312 and 314 is connected through a 
desired braking load 336 to the current collector 308 and then to the 
neutral trolley wire 212. The current which will flow to the braking load 
336 from the neutral point 334 is a unbalance current which flows to the 
field coil 310 from the continuously supplied trolley wire 206 when no 
voltage is applied to the trolley wires 208 and 210. Thus, the unbalance 
current flowing in the braking load 336 may be utilized to actuate braking 
means, such as, hydraulic brakes, disk brakes, magnetic brakes or the 
like. The actuation of the brakes by this unbalance current is operable 
even if the travelling object 300 is at rest. 
The following travelling object 300' has the same circuit connections as 
the travelling object 300 and therefore its component parts are designated 
by the same reference numerals but with a prime. 
The operation of this embodiment through the AC power control will now be 
described. Assume now that the travelling object 300 is present in the 
section between the section controllers 232 and 234 and no other 
travelling object is present in the preceding section in the direction of 
the movement of the travelling object 300. Consequently, no feeding 
current flows in the trolley wire 238 so that the current relay coil 268 
of the section controller 232 is not energized and the contacts 270 remain 
closed, thus supplying the AC feeding current to the trolley wires 248 and 
256. 
On the other hand, a current relay coil 272 of the section controller 234 
is energized by the feeding current flowing to the travelling object 300 
by way of a trolley wire 240, so that its contacts 274 are opened and the 
voltage is no longer applied to trolley wires 250 and 258 located in the 
section immediately following the section where the travelling object 300 
is present. 
In this case, the motor circuit of the travelling object 300 operates as 
follows. The field coils 310, 312 and 314 of the three-phase induction 
motor are supplied with the AC feeding current from the trolley wire 240, 
248 and 256, so that the rotor 315 is rotated and the travelling object 
300 is brought into the cruising speed operation. At that time, the 
current relay coils 316, 318 and 320 are all energized and their contacts 
322, 326 and 328 are all opened, thus supplying no unbalance current to 
the braking load 336 from the neutral point 334. 
Assume now that in this condition the following travelling object 300' 
proceeds into the section between the section controllers 234 and 236 
which immediately follows the section occupied by the travelling object 
300. Since there is no applied voltage to the trolley wires 250 and 258 as 
mentioned previously, current relay coils 318' and 320' of the travelling 
object 300' are deenergized so that their contacts 326' and 328' are 
closed and resistors 330' and 332' are connected to field coils 312' and 
314', respectively, thus effecting the dynamic braking. At the same time, 
the unbalance current flowing in a field coil 310' by the voltage from the 
trolley wire 242 now flows to the newtral trolley wire 212 through a 
braking load 336'. Consequently, the desired braking means is actuated to 
decelerate the travelling object 300', and the travelling object 300' is 
stopped, if necessary. 
When the preceding travelling object 300 passes through the section between 
the section controllers 232 and 234 while the travelling object 300' is 
being decelerated or after it has been brought to a stop, the current 
relay coil 272 of the section controller 234 is deenergized so that its 
contacts 274 are closed and the AC voltage is applied to the trolley wires 
250 and 258. Consequently, the current relay coils 318' and 320' of the 
travelling object 300' are energized and their contacts 326' and 328' are 
opened, thus releasing the dynamic braking and thereby accelerating the 
travelling object 300' to the cruising speed. 
It will thus be seen that in accordance with this embodiment, the desired 
automatic control of the operation of travelling objects can be 
accomplished only through the power control which controls the three-phase 
AC power supply to the three-phase induction motors mounted on the 
travelling objects, and particularly the braking control of the travelling 
objects can be accomplished through the combined use of the dynamic 
braking utilizing the features of the three-phase induction motor and any 
desired braking means operated by unbalance current, thus accomplishing 
only through the power control of the three-phase AC power any desired 
running conditions of the travelling objects, e.g., the constant speed 
operation, deceleration and stopping, acceleration, etc. 
FIG. 4 shows another embodiment of the travelling object motor circuit in 
which a magnet unit 354 with an exciting coil 355 is provided in place of 
the dynamic braking load 336 of the travelling object 300 shown in FIG. 3. 
A plate 350 is installed on the ground to cooperate with the magnet unit 
354. The plate 350 is made of a magnetic material or electrically 
conductive material. If the plate 350 is made of magnetic material, the 
desired braking will be effected by the magnetic force produced between 
the plate 350 and the magnet unit 354. If the plate 350 is made of 
electrically conductive material, the braking will be effected by the eddy 
current produced between the plate 350 and the magnet unit 354. The 
control of operation of the travelling object 300 equipped with the magnet 
unit 354 will be described in greater detail later. 
Referring now to FIGS. 5 and 6, there is shown still another embodiment of 
the invention including means and a feeder circuit designed for 
automatically stopping a travelling object at a predetermined fixed 
position with a high degree of accuracy through the power control of 
three-phase AC feeding. 
In FIG. 5, arrows 340 and 342 define therebetween a block section, and an 
arrow 340 indicates a predetermined stop position for travelling object. 
In this case, the stop position should preferably be different from the 
break between the block sections. Magnetic belt units 344 and 346 are 
arranged within the block section with a predetermined spacing 
therebetween. Each of the magnetic belt units 344 and 346 has a belt 
member made of a magnetic material and adapted to be rotated circularly. 
Disposed on the exit side of the magnetic belt unit 344 is a plate 350 
made of a magnetic material or electrically conductive material and 
covering the stop position 340. 
On the other hand, a magnet unit 354 is mounted on a travelling object 300 
to produce a magnetic force between the magnet unit 354 and the magnetic 
belt units 346 and 344 when the travelling object 300 passes over the 
magnetic belt units 346 and 344. The magnetic unit 354 employs an 
electromagnet or permanent magnet. 
Each of the magnetic belt units 346 and 344 is designed so that its upper 
belt surface is rotated at a predetermined speed in the direction of 
movement of the travelling object shown by an arrow 548. Consequently, 
when the travelling object 300 proceeds onto the magnetic belt units 346 
and 344, respectively, the speed of the travelling object is synchronized 
with the rotation speed of the magnetic belt by the magnetic force 
produced between the magnet unit 354 on the travelling object and the 
magnetic belt units 346 and 344, respectively. 
When the travelling object 300 thus synchronized with the magnetic belt 
units 346 and 344 proceeds onto the plate 350, if the plate 350 is made of 
magnetic material, the magnetic braking is effected by the magnetic force 
produced between the plate 350 and the magnetic unit 354 on the travelling 
object thus stopping it, whereas if the plate 350 is electrically 
conductive material, an eddy current is induced in the plate 350 by the 
magnetic flux of the magnet unit 354 to the plate 350, and the reaction of 
the electromagnetic induction due to the eddy current applies a dragging 
force to the travelling object 300 to bring it to a stop. 
FIG. 6 shows a three-phase AC feeder circuit illustrated to positionally 
correspond with the units shown in FIG. 5, which is identical with the 
circuit construction for the section between the section controllers 232 
and 234 in FIG. 3, and therefore the like parts are designated by the like 
reference numerals. The travelling object is also identical with that 
shown in FIG. 4, and therefore its circuit connections will not be 
described. Only difference is that stop actuation contacts 356 are 
inserted in the branch lines 264 and 266 of the section controller 232. 
The contacts 356 are so designed that the contacts are opened to stop the 
travelling object entering this block section, while the contacts are 
closed to restart the travelling object which has been stopped. 
The operation of this embodiment will now be described with reference to 
FIGS. 5 and 6. In FIG. 5, when the travelling object 300 enters the block 
section at the position of the arrow 342, the travelling object 300 is 
decelerated by the dynamic braking due to the fact that the contacts 356 
are open and no voltage is applied to the trolley wires 246 and 256 in 
FIG. 6. 
Assume now that the magnetic belt unit 346 is rotating at a speed v.sub.1 
and the magnetic belt unit 344 is rotating at a speed v.sub.2 and that 
v.sub.1 &gt;v.sub.2. It is also assumed that the travelling object 300 is so 
designed that in response to the dynamic braking, the magnet unit 354 
employing an electromagnet is energized by the unbalance current supplied 
from the field coil of the three-phase induction motor on the travelling 
object. 
With these conditions, when the travelling object 300 proceeds to the 
position of the magnetic belt unit 346, the travelling object 300 is 
synchronously decelerated to the magnetic belt speed v.sub.1 by the 
magnetic force between the magnet unit 354 and the magnetic belt unit 346 
while the travelling object 300 is moving past the magnetic belt unit 346. 
Thereafter, when the travelling object 300 is again decelerated by the 
dynamic braking and proceeds to the position of the magnetic belt unit 
344, the travelling object 300 is synchronously decelerated and 
consequently its speed is synchronized with the magnetic belt speed 
v.sub.2 as the travelling object 300 moves past the magnetic belt unit 
344. 
After leaving the magnetic belt unit 344, the travelling object 300 
proceeds to the plate 350 so that if the plate 350 is made of magnetic 
material, the magnetic brakes are applied, whereas if the plate 350 is 
made of non-magnetic good conductor, an eddy current braking force is 
applied, thus stopping the travelling object 300 at the fixed position 
indicated by the arrow 340. 
This stopping operation will be described in greater detail with reference 
to the graph of FIG. 7. The graph of FIG. 7 is a speed graph in which the 
ordinate represents the speed v meter/second of the travelling object 300, 
and the abscissa represents the distance L meter, the arrow 342 designates 
the entering end of the block section where the travelling object has a 
speed v.sub.p, and the arrow 340 designates the stop position. A straight 
speed line 400 of v.sub.1 represents the rotation speed of the magnetic 
belt unit 346, a straight speed line 500 of v.sub.2 represents the 
rotation speed of the magnetic belt unit 344, and it is assumed by way of 
example that v.sub.p =15 meter/second [54 kilometer/hour], v.sub.1 =10 
meter/second [36 kilometer/hour] and v.sub.2 =0.5 meter/second [1.8 
kilometer/hour]. 
Consider first the case where the weight of the travelling object is 
relatively low as in the case of an empty car carrying no passengers or 
cargos or the case where the running resistance is large. When the 
travelling object which has been decelerated by the dynamic braking at a 
point 360 reaches a point 365, the magnetic force between the travelling 
object and the magnetic belt unit 346 causes the travelling object to 
follow and move in synchronism with the magnetic belt speed v.sub.1. Then, 
as the travelling object moves past the magnetic belt unit 346 at a point 
370, the travelling object is again decelerated by the dynamic braking so 
that the travelling object is caused by the magnetic force between it and 
the magnetic belt unit 344 to follow and move in synchronism with the 
magnetic belt speed v.sub.2, and after leaving a point 380 the travelling 
object is stopped at the stop position 340 by the braking action between 
it and the plate 350. 
On the other hand, where the weight of the travelling object is relatively 
large or the running track is wet and hence the running resistance is low, 
the travelling object is subjected to the dynamic braking at the point 
360, moved at a point 385 to the magnetic belt unit 346 where it is braked 
by the magnetic belt by virtue of the magnetic force between it and the 
magnetic belt unit 346 to increase the deceleration gradient, synchronised 
with the speed v.sub.1 of the magnetic belt unit 346 at the point 370, 
again subjected to the dynamic braking and moved at a point 390 to the 
magnetic belt unit 344 where it is subjected to the magnetic braking to 
increase the deceleration gradient, synchronized with the speed v.sub.2 of 
the magnetic belt unit 344 at the point 380, and then stopped at the stop 
position 340 by the braking force between it and the plate 350. 
If the fixed position stopping system of this invention is not employed and 
a travelling object is simply decelerated, depending on the weight of the 
travelling object, the travelling object will be stopped at a point 395 or 
396 which is considerably deviated from the predetermined stop position. 
Thus, in accordance with the fixed position stopping system of this 
invention, irrespective of the variation in the weight of a travelling 
object or the variation of the road surface friction, the travelling 
object can be stopped at a predetermined fixed position with a high degree 
of accuracy, and the invention has a great advantage of accomplishing the 
automatic fixed position stop control without using any special travelling 
object detecting means or signal control system. 
Further, the spacing and rotation speed of the magnetic belt units used in 
the fixed position stop system of this invention should be suitably 
determined in accordance with the various running conditions of travelling 
objects. 
While, in the embodiment described above, the travelling object is 
synchronously decelerated by two units of the magnetic belt, the number of 
magnetic belt units and the length of the belts or the block section 
length may be suitably determined in accordance with the specifications of 
a desired system. 
With the above-described stop control of this invention, a travelling 
object can be synchronously decelerated by the magnetic force produced 
between the travelling object and the magnetic belt units, with the result 
that the speed control of the travelling object can be accurately effected 
until the travelling object reaches a fixed stopping position without 
being affected by any variation in the weight of the travelling object or 
the running resistance, e.g., the track surface conditions. Further, the 
use of the magnetic braking after the synchronous deceleration by the 
magnetic belt, has the effect of further improving the stopping accuracy. 
Still further, since the synchronous deceleration by the magnetic belts 
utilizes magnetic force, the travelling object can proceed to and move 
past the magnetic belts smoothly, thus preventing any sudden change in the 
acceleration and thereby ensuring improved riding confortability. Still 
further, by virtue of the fact that the magnetic belts and plate and the 
travelling object magnet unit are operable in contact or noncontact manner 
with each other, the use of the fixed point stopping system of this 
invention has no danger of producing noise and vibration and causing 
mechanical wear and tear to the equipment and installations. In addition, 
this fixed position stop control can be incorporated as such in the 
control system of this invention for controlling the operation of 
travelling objects through the power control of DC constant voltage 
feeding. 
It will thus be seen from the foregoing description that in accordance with 
the control system of this invention for controlling the operation of 
travelling objects through power control, the automatic operation of 
travelling objects can be accomplished by simply switching on and off the 
feeding voltage without requiring any specially designed separate control 
circuits, means for detecting for example the location of the travelling 
objects or separate operation order control means for providing any 
desired operation pattern, etc., and this has the effect of achieving 
considerable simplification of the equipment on the ground as well as the 
equipment on the travelling objects and greatly reducing the equipment 
cost as compared with the prior art automatic train operation systems. 
Still further, the simplified construction of the equipment and 
installations has the effect of sufficiently reducing the failure rate, 
making it possible to adapt the important feeding equipment and apparatus 
for a parallel change-over system to ensure a high degree of redundancy 
which permits a restoration in a very short period of time in the event of 
a failure or the like, and ensuring the maintenance of the continuous 
automatic operation of travelling objects.