Field
[0001] The present invention relates to a speed control device that detects a location and speed of a train vehicle, and controls speed of the train vehicle on the basis of the location and speed detected.
Background
[0002] In Patent Literature 1 that is an example of a conventional technology, a technology is disclosed that aims to "quickly detect a slide even when the slide occurs again immediately after re-adhesion of a wheel, in a method for detecting a slide of the wheel", and corrects a speed detection error due to the slide by using "a method that
stores previous speed data (V2 Vn, where n>3) with
respect to speed data VI of current measurement time, and calculates average acceleration or deceleration on the basis of those speed data for each measurement, to detect the slide of the wheel on the basis of the average acceleration or deceleration. When it is detected that the wheel recovers from the slide and re-adhesion occurs, all the speed data at the time are replaced with the maximum speed in the speed data".
Citation List
Patent Literature
[0003] Patent Literature 1: Japanese Patent Application
Laid-open No. H6-86404
Summary
Technical Problem
[0004] However, according to the conventional technology, because all the speed data are replaced with the maximum speed in the speed data in detecting the slide, when a slide or wheel slip occurs, the speed data are replaced with the maximum speed even though they are not actually in the maximum speed. For that reason, there has been a problem in that speed detection accuracy decreases for each time when the slide or wheel slip occurs.
[0005] The present invention has been made in view of the above, and it is an object to obtain a speed control device capable of detecting speed and location more accurately than before.
Solution to Problem
[0006] To solve the above-described problem and achieve the object, the present invention includes: a first calculation unit to calculate first location information and first speed information from output of a speed generator; a second calculation unit to calculate second location information and second speed information from output of a speed sensor; a route database storage unit to store information to select one of a calculation result of the first calculation unit and a calculation result of the second calculation unit in accordance with a location of a vehicle; and a selection unit to select one of the calculation results on the basis of the information of the route database storage unit to output the information as location information and speed information. Speed of the vehicle is determined on the basis of the location information and speed information selected.

[0007] According to the present invention, there is an effect that the speed and location can be detected more accurately than before.
Brief Description of Drawings
[0008] FIG. 1 is a block diagram illustrating a configuration example of a speed control device according to a first embodiment.
FIG. 2 is a flowchart illustrating an operation example of the speed control device according to the first embodiment.
FIG. 3 is a diagram illustrating an example of a data structure of a route database storage unit in the first embodiment.
FIG. 4 is a block diagram illustrating a configuration example of a speed control device according to a second embodiment.
FIG. 5 is a flowchart illustrating an operation example of the speed control device according to the second embodiment.
FIG. 6 is a diagram illustrating a general configuration of hardware to realize the device in the first and second embodiments.
Description of Embodiments
[0009] Hereinafter, a speed control device according to
embodiments of the present invention will be described in
detail with reference to the drawings. Incidentally, the
invention is not limited to the embodiments.
[0010] First Embodiment
FIG. 1 is a block diagram illustrating a configuration example of a speed control device according to a first embodiment of the present invention. A speed control

device 10 illustrated in FIG. 1 is mounted on a vehicle 20 that includes a speed generator 1 to generate and output a pulse according to the number of rotations of a wheel, and a speed sensor 2 to detect speed by reflection of an electromagnetic wave without using rotation of the wheel and output the amount of detection. The speed control device includes a first signal detection unit 3 that converts the pulse into a pulse signal Sin and output the pulse signal Sin; a second signal detection unit 4 that converts the amount of detection into a detection signal S2n and output the detection signal S2n; a first calculation unit 5 that receives input of the pulse signal Sin, and calculates and outputs first location information Pin and first speed information Vln of the vehicle 20; a second calculation unit 6 that receives an input of the detection signal S2n, and calculates and outputs second location information P2n and second speed information V2n of the vehicle 20; a route database storage unit 8 that stores information to select any of the first location information Pin, the second location information P2n, the first speed information Vln, and the second speed information V2n in accordance with a location of the vehicle 20; and a selection unit 7 that receives inputs of the first location information Pin, the second location information P2n, the first speed information Vln, and the second speed information V2n, and selects any set of location information and speed information on the basis of the information of the route database storage unit 8, and outputs location information P3n and speed information V3n. [0011] In addition, the vehicle 20 includes a speed checking unit 9 that creates a speed checking pattern, receives inputs of the location information P3n and speed information V3n selected, and outputs a brake command when

the location information P3n and speed information V3n exceed does not fall within the speed checking pattern; a brake device 11 that receives an input of the brake command and performs braking of the vehicle 20; and a pickup coil 12. The information of the route database storage unit 8 is stored as a location and speed signal selection flag, for example.
[0012] Incidentally, the vehicle 20 can determine a current location using the pickup coil 12. When the pickup coil 12 passes over a ground coil 13 on a route, a ground coil ID is transmitted from the ground coil 13 to the pickup coil 12 by electromagnetic coupling or short range wireless transmission. The pickup coil 12 transmits the ground coil ID received to the selection unit 7, as telegraph information. The route database storage unit 8 stores a relationship between the ground coil ID and an absolute location, and the selection unit 7 uses a route database and the ground coil ID received to determine an absolute location of the vehicle 20. Alternatively, in a case where a data transmission capacity is large between the pickup coil 12 and the ground coil 13, the kilometrage may be transmitted from the ground coil 13 to the pickup coil 12, instead of the ground coil ID. In a case where the kilometrage can be transmitted from the ground coil 13 to the pickup coil 12, the route database storage unit 8 does not have to store a relationship between the ground coil ID and the kilometrage.
[0013] Incidentally, the speed sensor 2 is not limited to a specific sensor as far as it is a sensor capable of detecting the speed by using reflection of the electromagnetic wave without using rotation of the wheel. The speed sensor 2 includes an output unit to radiate the electromagnetic wave onto a road surface, and a detection

unit to detect the electromagnetic wave reflected from the road surface. In addition, the electromagnetic wave includes a radio wave and light. The speed sensor 2 includes a Doppler sensor.
[0014] Incidentally, in a case where the first calculation unit 5 and the second calculation unit 6 are capable of being input an output of the speed generator 1, the first signal detection unit 3 and the second signal detection unit 4 are not necessary. That is, the first signal detection unit 3 and the second signal detection unit 4 are not essential constituents.
[0015] Incidentally, vehicle location information is information on the location of the vehicle, and examples of the location information include an absolute location of the vehicle, and the amount of location change of the vehicle that is information on the location of the vehicle. Vehicle speed information is information on the speed of the vehicle, and examples of the speed information include vehicle speed and vehicle acceleration.
[0016] FIG. 2 is a flowchart illustrating an operation example of the speed control device according to the first embodiment of the present invention. Incidentally, this processing is repeatedly performed at a set constant period.
[0017] First, the processing is started, and the first signal detection unit 3 converts the pulse according to the number of rotations of the wheel output by the speed generator 1 into the pulse signal Sin and outputs the pulse signal Sin (SI). The first calculation unit 5 calculates and outputs the location information Pin and speed information Vln of the vehicle 20 on the basis of the pulse signal Sin (S2). The second signal detection unit 4 converts the amount of detection output by the speed sensor 2 into the detection signal S2n and outputs the detection

signal S2n (S3). The second calculation unit 6 calculates and outputs the location information P2n and speed information V2n of the vehicle 20 on the basis of the detection signal S2n (S4). Here, steps SI and S2, and steps S3 and S4 may be performed sequentially, or may be performed in parallel.
[0018] The selection unit 7, on the basis of the route database stored in the route database storage unit 8, selects any of the set the location information Pin and speed information Vln, and the set of the location information P2n and speed information V2n, and outputs location information and speed information that are selected, as the location information P3n and speed information V3n. Here, the selection unit 7 selects location information and speed information depending on whether or not the current location of the vehicle 20 is within a data-use-prohibition section where use of data from the second signal detection unit 4 (S5) is prohibited. For such determination, the location and speed signal selection flag is used, for example. The location and speed signal selection flag indicates information to select any one of the set of the location information Pin and speed information Vln, and the set of the location information P2n and speed information V2n. For example, when the current location of the vehicle 20 is within the data-use-prohibition section where use of data from the second signal detection unit 4 is prohibited, the location and speed signal selection flag is set to "1", and when the location is outside the data-use-prohibition section where use of data from the second signal detection unit 4 is prohibited, the location and speed signal selection flag is set to "0". At this time, when the location and speed signal selection flag is "1", the current location of the

vehicle 20 is within the use-prohibition section where use of data from the second signal detection unit 4 is prohibited (S5: Yes), so that the selection unit 7 selects the location information Pin and speed information Vln calculated from data of the first signal detection unit 3
(S6). On the other hand, when the location and speed signal selection flag is "0", the current location of the vehicle 20 is outside the use-prohibition section where use of data from the second signal detection unit 4 is prohibited (S5: No), so that the selection unit 7 selects the location information P2n and speed information V2n calculated from data of the second signal detection unit 4
(S7). The selection unit 7 outputs the location information and speed information selected in this way, as the location information P3n and speed information V3n, and ends the processing.
[0019] The speed checking unit 9 to which the location information P3n and speed information V3n are input, compares the speed checking pattern that the speed checking unit 9 has created with the location information P3n and speed information V3n. The speed checking unit 9, in a case where the location information P3n and speed information V3n does not fall within the speed checking pattern, outputs the brake command, and, in a case where the location information P3n and speed information V3n falls within the speed checking pattern, ends the processing without outputting the brake command. Note that, the speed checking pattern is created in accordance with a speed limit of the vehicle 20.
[0020] FIG. 3 is a diagram illustrating an example of a data structure of the route database storage unit 8. FIG. 3 illustrates the first calculation unit 5, the second calculation unit 6, the selection unit 7, and the route

database storage unit 8. The route database storage unit 8 illustrated in FIG. 3 sequentially stores information specifying the data-use-prohibition section where use of data from the second signal detection unit is prohibited. A prohibition section of a prohibition section number 1 is from a point of kilometrage 12,135.5 m to a point of kilometrage 12,145.5 m. A prohibition section of a prohibition section number 2 is from a point of kilometrage 13,224.7 m to a point of kilometrage 13,234.7 m. Prohibition sections of prohibition section numbers from 3 to 7 are omitted. A prohibition section of a prohibition section number 8 is from a point of kilometrage 24,324.8 m to a point of kilometrage 24,326.8 m. A prohibition section of a prohibition section number 9 is from a point of kilometrage 27,624.7 m to a point of kilometrage 27,629.7 m. In sections other than these prohibition sections, the selection unit 7 selects the location information P2n and speed information V2n that are not influenced by the slide or wheel slip, as the location information P3n and speed information V3n. In these prohibition sections, the selection unit 7 selects the location information Pin and speed information Vln, as the location information P3n and speed information V3n.
[0021] Incidentally, as illustrated by a dotted line in FIG. 3, it may be configured such that, when a section in which an intensity of a reflected signal received by the sensor that uses reflection of the electromagnetic wave is equal to or less than a set threshold value and the reflection intensity is insufficient is newly found in test traveling, the selection unit 7 can register the section as a prohibition section in the route database storage unit 8, and update the route database.
[0022] For the speed information detected by the first

signal detection unit 3, calibration is performed in normal traveling during which no wheel slip or slide occurs, whereby accuracy required for the speed control device 10 is secured, and the first signal detection unit 3 can detect the speed without being influenced by a structure around a rail. Note that, the accuracy required for the speed control device 10 is generally about ±5 km/h. However, in a wheel on which the brake device 11 acts and that is mounted on an axle driven by a motor, the slide may occur in braking, and the wheel slip may occur in power running. When the wheel slip or slide occurs in this way, there is a possibility in that speed information detection accuracy decreases and a large error occurs with respect to a target value.
[0023] On the other hand, the speed information V2n detected by a sensor that does not use rotation of the wheel, for example, the Doppler sensor, is not influenced by the wheel slip and slide, so that accuracy above a certain level is guaranteed in both braking and power running. However, because such a sensor uses reflection of the electromagnetic wave, the intensity of the reflected wave may be insufficient depending on the structure between rails or around the rails, and accuracy of the speed information may not be guaranteed. The route database storage unit 8 stores in advance information on a place where it is difficult for the sensor, which uses reflection of the electromagnetic wave without using rotation of the wheel, to perform accurate detection. Examples of the places where it is difficult for the sensor that uses reflection of the electromagnetic wave to perform accurate detection include a railroad bridge where no reflected wave can be obtained since there is no structure under the rail, and a sharp curve where an irradiation position largely

deviates from the rail.
[0024] Therefore, according to the present embodiment, the speed generator and the sensor using reflection of the electromagnetic wave are used in combination. In a place
5 where the sensor that uses reflection of the
electromagnetic wave can perform accurate detection, a detection result of the sensor that uses reflection of the electromagnetic wave and is not influenced by the wheel slip and slide is used whereas in a place where it is
D difficult for the sensor that uses reflection of the
electromagnetic wave cannot perform accurate detection, a detection result of the speed generator is used, whereby the two sensors can be used complementarily. Accordingly, influence of the wheel slip and slide and influence due to
5 a rail installation environment to reflection of the electromagnetic wave, with respect to the location information and speed information, can be eliminated as much as possible. For that reason, there is an effect in that the speed and location can be detected more accurately
D than in the past.
[0025] Second Embodiment
FIG. 4 is a block diagram illustrating a configuration example of a speed control device according to a second embodiment of the present invention. A speed control
5 device 10a illustrated in FIG. 4 is different from the speed control device 10 illustrated in FIG. 1 in that a selection unit 7a is included instead of the selection unit 7. The selection unit 7a includes a wheel slip and slide detection unit 14.
D [0026] FIG. 5 is a flowchart illustrating an operation example of the speed control device according to the second embodiment of the present invention. The flowchart illustrated in FIG. 5 is the same as the flowchart

illustrated in FIG. 2 up to step S5. When the location and speed signal selection flag is "1", the current location of a vehicle 20a is within the prohibition section where use of the second signal detection unit 4 (S5: Yes) is prohibited, so that it is determined whether or not an amount of speed change per unit time AVln/t is within a range of vehicle performance (S5a). That is, a vehicle's maximum deceleration pmax that is a negative value and a vehicle's maximum acceleration amax that is a positive value are used, and it is determined whether or not pmax0 or slide occurs, the speed and location can be detected with high accuracy by performing minimum correction. [0029] Incidentally, in the first and second embodiments, the configuration of the first calculation unit 5, the second calculation unit 6, the selection unit 7 or the
15 selection unit 7a, and the route database storage unit 8
can be realized by including at least a processor, a memory, and an input/output interface, and the operation can be realized by software. FIG. 6 is a diagram illustrating a general configuration of hardware to realize such a device.
30 The device illustrated in FIG. 6 includes a processor 30, a memory 31 and an input/output interface 32 connected by a bus 33. The processor 30 uses input data to perform calculation and control with software. The memory 31

stores the input data or data necessary for the processor
30 to perform the calculation and control. The
input/output interface 32 receives at least the pulse
signal Sin from the first signal detection unit 3 and the
detection signal S2n from the second signal detection unit
4, and transmits the location information P3n and speed
information V3n selected by the processor 30 to the speed
checking unit 9. Note that, each of the processor 30 and
the memory 31 may be provided for more than one.
[0030] The configurations described in the above embodiments describe examples of content of the present invention, and can be combined with other known techniques, and also part of the configuration can be omitted or modified without departing from the gist of the present invention.
Reference Signs List
[0031] 1 speed generator; 2 speed sensor; 3 first signal detection unit; 4 second signal detection unit; 5 first calculation unit; 6 second calculation unit; 7, 7a selection unit; 8 route database storage unit; 9 speed checking unit; 10, 10a speed control device; 11 brake device; 12 pickup coil; 13 ground coil; 14 wheel slip and slide detection unit; 20, 20a vehicle; 30 processor;
31 memory; 32 input/output interface; 33 bus.

1. A speed control device mounted on a vehicle that
includes a speed generator to generate and output a pulse
according to a number of rotations of a wheel, and a speed
sensor to detect speed using reflection of an
electromagnetic wave without using rotation of the wheel
and output an amount of detection, the speed control device
comprising:
a first calculation unit to receive an input of a pulse signal that is based on an output of the speed generator, and to calculate and output first location information and first speed information of the vehicle;
a second calculation unit to receive an input of a detection signal that is based on an output of the speed sensor, to calculate and output second location information and second speed information of the vehicle;
a route database storage unit to store information to select any of the first location information, the second location information, the first speed information, and the second speed information, in accordance with a location of the vehicle; and
a selection unit to receive inputs of the first location information, the second location information, the first speed information, and the second speed information, to select any location information and speed information on a basis of the information of the route database storage unit, and to output location information and speed information that are selected, wherein
speed of the vehicle is determined on a basis of the location information and speed information that are selected.
2. The speed control device according to claim 1, wherein

the information of the route database storage unit includes information specifying a use-prohibition section where use of the second location information and the second speed information is prohibited, and
the selection unit
selects the first location information and the first speed information in the use-prohibition section, and
selects the second location information and the second speed information in a section other than the use-prohibition section.
3. The speed control device according to claim 1, wherein
the selection unit includes a wheel slip and slide detection unit, and
when the wheel slip and slide detection unit detects a slide or wheel slip, the selection unit corrects the first location information and the first speed information, to output corrected values as the location information and speed information that are selected.