GB2273624A

GB2273624A - Vehicle data recorder.

Info

Publication number: GB2273624A
Application number: GB9226174A
Authority: GB
Inventors: Richard George Thomason
Original assignee: Westinghouse Brake and Signal Co Ltd; Westinghouse Brake and Signal Holdings Ltd
Current assignee: Siemens Mobility Ltd
Priority date: 1992-12-16
Filing date: 1992-12-16
Publication date: 1994-06-22
Also published as: GB9226174D0

Abstract

A vehicle data recorder comprises a video camera (6) for detecting images external to the vehicle and a compression means (13) for compressing the video data to provide a compressed video data signal. A status data collection means (2) detects the status (e.g. speed, control settings) of the vehicle, and a recording means (3) receives the compressed video data signal and the status signal in synchronisation with each other for recording in a non volatile impact protected memory (4). This allows video images of views external to the system to be recorded, to assist in the analysis of incidents involving the vehicle. <IMAGE>

Description

A DATA RECORDER The present invention relates to a data recorder, in particular a data recorder suitable for monitoring a vehicle (in particular a railway vehicle) to record data concerning vehicle-related incidents, such as crashes.

Data recorders (or "incident recorders") are known which record data concerning the status of a system, such as a vehicle, for use in routine maintenance of the system or for determining the cause of an incident involving the system, such as a vehicle crash. However, many incidents are caused not by faults in the system but by external factors. For example, accidents to railway trains may be caused by faulty railway tracks, obstructions on the tracks, or by a train's driver responding incorrectly to external signals - by driving the train past a "stop" signal, for instance. These are not recorded by conventional data recorders.

According to the present invention there is provided a data recorder for recording data, the data recorder comprising: video data collection means including a video camera for detecting images and providing a video signal containing video data defining those images, and compression means for compressing the video data to provide a compressed video data signal; status data collection means for sensing the status of a system and providing a status signal containing status data defining that status; and recording means for receiving the compressed video data signal and the status signal and including an impact- and thermal-protected non-volatile memory for recording the compressed video data and the status data in synchronisation with each other.

This data recorder allows video images of views outside the system, including views of the external factors which may cause incidents, to be recorded.

The video signals and the status signals are suitably recorded in synchronisation so that the video data defining the image or images detected at any time and the status data detected at that time may be identified.

This may conveniently be done by the video data and the status data being recorded in a predetermined order.

Alternatively, the recording means may comprise clock means for generating a synchronisation signal (or "time code") which is recorded in the memory to allow the video data and status data recorded at or around any one time to be located.

The video camera suitably detects individual image frames, in which case the video data suitably comprises a series of data relating to individual frames. More than one video camera may be provided, in which case the cameras may each operate alternately or continuously; suitably each video camera detects video frames of views external to the system.

The video data and/or the compressed video data may suitably be in the form of digital signals. The video data collection means may suitably include a buffer memory for storing the video data, from which the compressed video data may be transmitted intermittently to the recording means, suitably in a response to a video request signal generated by control means in the recording means.

The memory of the recording means may suitably include a first non-volatile memory for recording the compressed video data and a second non-volatile memory for recording the status data.

The system is suitably a railway train or vehicle, in which case the data recorder may suitably include a first video camera for detecting a view ahead of the railway train or vehicle and a second video camera for detecting a view behind the railway train or vehicle.

The present invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a schematic view of a first embodiment of a data recorder; and Figure 2 is a schematic view of a second embodiment of a data recorder.

The data recorder shown in Figure 1 comprises a video data collector 1 and a status data collector 2 which transmit video data signals and status data signals respectively to a recorder unit 3. The recorder unit records the data in a non-volatile memory 4, from which the data can be downloaded for analysis, for example to determine the cause of an accident. The recorder unit 3 comprises an data recorder controller 5. This controls the passage of data from the data collector means 1,2 to the memory 4 when the data is to be recorded, and from the memory 4 when the data is to be downloaded.

Whilst the data recorder is recording data, for example during the operation of the system it is to monitor, the status data collector 2 collects digital and/or analog status data concerning the status of the system. For example, if the system is a railway train, the status data collection means may receive data from sensors for detecting the speed of the train and the settings of its controls. This data is transmitted to the controller 5 which passes it to the memory 4 for recordal. To save memory, the controller 5 may filter the status data so that only the changes in the system's status (as represented by variations in the status data) are recorded in the memory 4.

At the same time, the video data collector 1 collects signals representing video images frame by frame from a video camera 6. These are digitised by video digitiser 7 and then stored in a video memory buffer 8. At suitable intervals, the controller 5 transmits a video sample request signal (on line 9) to the video data collector 1 via communication units 10 and 11. In response to this signal the communication unit 11 transmits a signal on line 12 to the digitiser 7 to command it to temporarily suspend the passing of signals to the buffer 8. Meanwhile, the contents of the buffer 8 are compressed by a video data compressor unit 13 and the compressed video data is then transmitted via communication units 11 and 10 to the controller 5. This passes the data to the memory 4 for recordal. The buffer 8 is then emptied and the digitiser 7 begins passing signals to it again.

To allow the data to be analysed when it has been downloaded, the video data and the status data are stored in synchronisation so that the video data representing an image or images collected at any time and the status data collected at or around the same time may be identified.

This may be achieved by storing the data in a predetermined order or by recording synchronisation data together with items of status data or video data which are to be recorded. The synchronisation data may represent a time, as generated by a clock in the controller 5.

The memory 4 has two separate memory units 14,15 for storing, respectively, the video data and the status data. These can suitably hold at least one hour's data.

So that the data is not lost in the event of, for example, a crash of a railway vehicle in which the unit is installed, the memory units 14,15 are non-volatile: they are protected suitably from heat and impact or shock.

After a crash or during routine maintenance the recorded data may be analysed by a computer 16. In response to a data request signal (on line 17) from the computer 16 the incident recorder transmits (downloads) the contents of the memory to the computer. When the data have been downloaded in this way the video data is decompressed by the computer and the video images displayed. The status of the system and the video images can be displayed together on the same screen of the computer, the status being displayed graphically if appropriate. Because the video and status data are stored in synchronisation they can be displayed in synchronisation so that the status of the system at any time, as indicated by the status data, and the external conditions then, as indicated by the video images, can be examined.

To save memory, the video frames may be captured by the video data collector 1 from the camera 6 at small intervals rather than continuously.

More than one video camera may be used to detect the images. For example, on a railway train one camera may be provided to detect images of the view ahead of the train and another to detect images of the view behind the train. These may collect data continuously or alternately, under the control of the controller 5.

Figure 2 shows an alternative embodiment of a data recorder in which the memory 4 is configured in two discrete portions 4a and 4b which hold the video data memory 14 and the status data memory 15 respectively.

The data stored in the memories are syncronised by the storage of time codes idenifying the times at which the data are stored. When the recorded data is to be analysed it may be downloaded to the computer 16 from memories 4a and 4b.

Claims

1. A data recorder for recording data, the data recorder comprising: video data collection means including a video camera for detecting images and providing a video signal containing video data defining those images, and compression means for compressing the video data to provide a compressed video data signal; status data collection means for sensing the status of a system and providing a status signal containing status data defining that status; and recording means for receiving the compressed video data signal and the status signal and including an impact- and thermal-protected non-volatile memory for recording the compressed video data and the status data in synchronisation with each other.

2. A data recorder as claimed in claim 1, wherein the video camera detects individual image frames and the video data comprises a series of data relating to individual frames.

3. A data recorder as claimed in claim 2, wherein the recording means comprises clock means for generating synchronisation data, the synchronisation data being recorded in the memory to indicate the synchronisation of each one of the frames with the recorded status data.

4. A data recorder as claimed in any preceding claim, wherein the video data is in digital form.

5. A data recorder as claimed in any preceding claim, wherein the video data collection means comprises a video memory for storing the video data.

6. A data recorder as claimed in claim 5, wherein the recording means includes control means for generating a video request signal and wherein in response to the video request signal the video data collection means transmits to the recording means video data stored in the video memory.

7. A data recorder as claimed in any preceding claim, wherein the recording means includes a first non-volatile memory for recording the video signals and a second nonvolatile memory for recording the status signals.

8. A data recorder as claimed in any preceding claim, wherein the recording means records variations in the status data.

9. A data recorder as claimed in any preceding claim, wherein the video camera detects video frames of views external to the system.

10. A data recorder as claimed in any preceding claim, wherein the system is a railway train or vehicle.

11. A data recorder as claimed in claim 10 as dependent on claim 9 including a first video camera for detecting a view ahead of the railway train or vehicle and a second video camera for detecting a view behind the railway train or vehicle.

12. A data recorder as claimed in claim 11, wherein views are detected alternately by the first and second video cameras.

13. A data recorder substantially as herein described with reference to the accompanying drawings.