GB2297253A

GB2297253A - Walking aid for the blind

Info

Publication number: GB2297253A
Application number: GB9601420A
Authority: GB
Inventors: Russell George Kelsall
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-01-25
Filing date: 1996-01-24
Publication date: 1996-07-31
Also published as: GB9601420D0

Description

WALKING AID FOR THE BLIND The present invention relates to aids for disabled people, and particularly, although not exclusively, to an obstacle locating device for use as a walking aid directed at helping blind people.

Conventionally, blind or partially sighted people find their way using a stick, of around 1-1.5m in length, with which they feel their way along pavements, curbs etc. Conventionally, blind people sweep the stick from side to side in front of their intended path, in order to detect any obstacles in their way. Obstacles are detected by the noise of the stick hitting an object, and by the feel of the stick hitting the object.

However, whilst the conventional stick is versatile and convenient, it requires skill in its use, and it is often some time before a blind person can use the stick to its full advantage. As a lower end of the stick is freely waved around in the air, it may be difficult for a person who is new to the use of the stick to accurately gauge the distance of obstacles and the position of the obstacles relative to their intended path.

Specific embodiments of the present invention aim to improve on the conventional stick for blind people.

According to one aspect of the present invention there is provided an obstacle locating device comprising one or a plurality of sensors arranged to sense obstacles; and an elongate shaft having an upper end adapted for holding by a person, and a lower end adapted for carrying the sensor(s).

Thus, a blind person may hold the device out in front of them, the first end of the shaft being held distal to the persons body, the second end of the shaft being held with the persons hand.

Preferably, there are provided a plurality of sensors. There may be provided a left sensor for detecting when an obstacle lies to the left of the device, a centre sensor for detecting when an obstacle lies to a centre position of the device, and a right sensor for detecting when an obstacle lies to the right of the device.

A said sensor may comprise an electrical switch, actuated by a lever, for example an elongate wire. A plurality of said sensors may be arranged in an array, the array lying in a line transverse to the a main length of the shaft.

The sensor may comprise a flexible skirt which extends between first and second sensors. Where the sensors are elongate fingers, a length of each sensor finger may extend in a direction transverse to a direction of travel of the obstacle locating device in use. The skirt preferably extends in a direction transverse to a direction of travel of the device. The skirt is preferably formed of a flexible sheet material, eg. a plastics material. The skirt is preferably arranged to activate one or more said sensors when deformed by collision with an obstacle. Where the skirt is deformed by collision at a position between said first and second sensors, the skirt may activate said first and/or second sensor(s).

A said sensor may comprise an opto-electronic sensor device, or a radio transmitter/receiver device, in either case for detecting a signal which is transmitted from the device and reflected from an obstacle in the path of the user.

There may be provided means for supporting the lower end of the shaft when held distally from the persons body. Such a means may comprise a wheel attached at the lower end of the shaft. The lower end of the shaft may be supported at a predetermined height above the terrain over which the person travels. The wheel may be a single wheel, or a pair of wheels.

Preferably, the device comprises an indicator means for indicating when a said sensor detects an obstacle. The indicator means preferably comprises a touch indicator, which is adapted to transmit a signal directly to a users hand, for indicating when an obstacle is detected. Such a touch indicator may comprise one or a plurality of plungers. The indicator means may be located in a handle attached to the upper end of the shaft, each indicator arranged to protrude from or retract into the handle according to a sensor signal received from a respective said sensor.

Preferably the indicator means are capable of producing a signal in response to an obstacle sensed to the left, and/or centre, and/or right of the device. For example, the indicator means may comprise a handle which is grasped by a user, the handle having one or a plurality of moveable plungers, each plunger capable of retracting into or extending from the handle, so as to either project from the housing, in which case the plunger(s) can be felt by the user as a bump on the handle, or to be retracted into the handle, in which case the plunger may be smooth with the surface of the handle.

Preferably, there are provided three such indicators, one for receiving a signal from a left sensor, one for receiving a signal from a centre sensor and one for receiving a signal from a right sensor. When an obstacle is detected on the left of the device, the left plunger may be activated so as to protrude from the handle, whereas when an object is detected from the right of the device, the right plunger may be activated to protrude from the handle.

The device may be steered by tilting the device slightly to a first, side or to a second, right side as required, for turning the lower end of the shaft to follow a left turn or a right turn.

Preferably, means are provided for ensuring that the central position of the device follows a path which is selectable by a user. Typically, the means for ensuring the central path of the device follows a desired path may comprise the wheel.

A said indicator means may comprise an audible alarm. The alarm may generate a plurality of distinct tones, the distinct tones indicating a direction in which an obstacle has been sensed, with respect to a centre position of the device.

The centre position of the device may be a position which lies a vertical plane, the vertical plane coinciding with a main length of the shaft in use.

According to a second aspect of the present invention, there is provided an obstacle locating device for a disabled person, the device comprising one or a plurality of sensors arranged to sense obstacles; an elongate shaft having an upper end adapted for holding by the person and a lower end adapted for carrying the sensor(s); and a pair of wheels wherein said sensor(s) is or are positioned between the wheels, the wheels being connected with the lower end of the shaft, a lower end of the shaft being positioned nearer one wheel of the pair of wheels than the other wheel. The lower end of the shaft in use may be positioned either to a left hand side or a right hand side of the person.

Suitably, the pair of wheels are connected by a cross member such that in use, a main length of the cross member lies substantially transverse to a main length of the shaft.

Preferably, the wheels are spaced apart along a direction transverse to the intended direction of travel of the device. The wheels are preferably spaced apart in a direction transverse to the direction of the main length of the shaft.

The lower end of the shaft may be moveable between the position nearer the left wheel and the position nearer the right wheel. This may allow the second device to be adjustable for either right handed or left handed persons.

The sensor(s) is or are preferably mounted on the cross member.

For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings, in which: Figure 1 shows an obstacle locating device according to a first specific embodiment of the present invention; Figure 2 shows in front view the device of figure 1; Figure 3 shows in schematic view, an indicator mechanism incorporated into a handle of the device of figure 1; Figure 4 shows in cut away view, a sensor mechanism provided at a lower end of the walking aid of figure 1; Figure 5 shows a second obstacle locating device according to a second embodiment of the present invention; and Figure 6 shows a third obstacle locating device according to a third specific embodiment of the present invention.

Referring to figures 1 to 4 of the accompanying drawings, an obstacle locating device, eg. a walking aid aimed particularly but not exclusively for blind or partially sighted persons, comprises an elongate shaft 1 having at an upper end, a hand grip 2 for gripping by a person, the hand grip including an indicator device 20 for indicating a direction of an obstacle at a lower end 3, a wheel 4, for carrying the lower end along a ground surface eg. a road or pavement; a laterally extending bar 5 present at the lower end of the shaft, and mounted to the bar a plurality, eg. three of sensor devices 6,7,8 distributed along a length of the bar, and arranged such that the sensors sweep an area in front of the device, when the device is pushed in a forward direction before the walking user, the sensors devices arranged to the left to the right and centrally compared with a centre position of the device corresponding with the wheel.

In use, a user pushes the device in front of them, along their intended path, steering the device by tilting the shaft to left or right as required.

The laterally extending bar 5, may comprise a tube 10 as shown in figure 4 of the accompanying drawings, the tube containing a plurality of the sensor devices, each sensor device comprising an elongate wire finger 11 pivoted about one end around a pivot point 12, such that a downwardly extending portion of the finger, when bumped into an object, is arranged to activate an electrical micro switch 14 between an OFF position and an ON position. Upon activation of the micro switch, the micro switch sends a signal to the indicator 20, located in the handle of the walking aid, as shown in figure 3 of the accompanying drawings.

The indicator 20 may comprise one or a plurality of relays. In this example, three relays are shown 21,22,23, each relay arranged for activating an individual plunger button 24,25,26 respectively, so that for example when a first sensor 8 on the left hand side of the device encounters an object, a first relay 21, operates to push a first button 25 out of the casing of the handle, so that it can be felt by a person holding the handle. Thus, when the first button 24 protrudes from the most forward end of the handle, this is a signal to a blind user that the first sensor finger, on the left of the device, has encountered an obstacle, and that an obstacle lies to the left of the persons path.

Where, for example the device encounters a kerb stone, the device being presented in a direction perpendicular to a main length of the kerb stone, all three sensor fingers will be activated more or less simultaneously, so that each of the three relays will activate and each of the first to third buttons will protrude from the casing of the handle. A person grasping the handle will detect through touch, that all three buttons are protruded, and will thereby gain information that an object lies completely across his path.

Similarly, where an obstacle is only on the right hand side of the persons intended path, the third sensor, on the right hand side of the device will be activated, and the third button, at the rear of the handle will protrude from the handle casing, thereby giving a signal to the user that an object lies to the right of the users intended path.

In other embodiments, significant variations on the device may be made, such that the sensor fingers may be replaced by, for example optoelectronic devices which detect obstacles in the path of the device by detection of light radiated by the opto-electronic device and reflected from the oncoming obstacle. In other embodiments, an electronic beam may scan from left to right, in an arc in front of the device, and an indicator, located in the handle of the device, may give a left, right or centre signal depending upon whether the electronic device detects a reflected signal from an obstacle to the left, to the centre, or to the right of the intended path of the user.

In further embodiments, the indicator may comprise an audible alarm.

For example in a version similar to that shown in figures 1 to 4, the first, second and third sensor fingers may be arranged to activate an audible alarm, at a first, second or third tone respectively to indicate obstacles to the left, centre or right respectively. Thus, a person who has good hearing, but poor feeling in their hand may find this embodiment of use.

On the other hand, a person who has poor hearing and poor sight but has good feeling in their hand, may find the embodiment of figures 1 to 4 more useful.

The sensor devices, and indicator device in the form of the moveable plunger buttons or audible alarm, is preferably powered from a battery, carried in a housing mounted to the device, for example a battery housing located adjacent the handle.

Referring to figure 5 of the accompanying drawings, there is shown in front view, a second obstacle locating device for a disabled person, eg. a blind person, according to a second specific embodiment of the present invention, the second obstacle locating device comprising a pair of wheels comprising a left hand wheel 100 and a right hand wheel 101, the wheels being arranged at either end of an elongate cross member 102 which connects the wheels, an elongate shaft 103 having at an upper end thereof, a handle 104 for gripping by the person and by which the person may push the device along the ground in front of the person, and the shaft at a lower end 103 thereof, being connected to the cross member 102 such that the shaft is placed either nearer the right hand wheel 101 than the left hand wheel 100, or vice versa the lower end of the shaft 102 may be connected to the cross member nearer the left hand wheel 100, than the right hand wheel 101, there being provided optionally a brace member 104 connecting the shaft 103 to the cross member 102 at a position between the lower and upper ends of the shaft, to add rigidity to the structure; one or a plurality of sensors 106-108 attached to the cross member at a position near the ground, for example below knee height and suitably below the height at which a conventional kerb stone may be expected, for example up to 50 cm's from ground level, the sensors comprising a left hand sensor 108 a centre sensor 107, and a right hand sensor 106.

The lower end of the shaft may be moveable between the left or right positions, adjacent the left or right wheels, to accommodate adjustment of the second device for eight left handed or right handed person.

In use, the second embodiment obstacle locating device is used substantially similarly to the first embodiment described herein above, except that steering of the second embodiment is made by movement of the handle at the upper end of the shaft 103 in a substantially arcuate movement either to the right hand side of the person using the device, or to the left hand side of the person using the device, such that the device turns about a locus between the left and right wheels.

Provision of the cross member, a main length of which is presented in use substantially perpendicular to a direction of travel, or intended direction of travel or the device, and the provision of two wheels spaced apart in a direction transverse to the intended direction of travel may enable a greater stability of the device.

The sensor indicator means, may be as described hereinabove with the reference to the first specific embodiment, and operation of the second obstacle locating device may be as described above with reference to a first obstacle locating device, in respect of the sensing operation of the sensors and communication of the sensor devices with the indicator means.

Referring to figure 6 of the accompanying drawings, there is shown a third obstacle locating device, which is substantially the same as the first obstacle locating device of figure 1, except with an improved sensor arrangement. The improvement to the sensor arrangement comprises an elongate sheet of flexible material in the form of a skirt 200, which is laid over the plurality of sensors 6,7,8, the sensors being in the form of elongate fingers extending forwardly of the obstacle locating device. The sheet of flexible material 200 is fixed at an upper end thereof to a laterally extending bar, to which the sensors are mounted, the arrangement being that the sheet lays over the plurality of sensors, and extends between the sensors, to form a skirt which sweeps a path in front of the device.

In use, if there is an obstacle in the intended path of a person using the third obstacle locating device, the obstacle, being for example a raised pipe outlet, which the person may trip over, then this obstacle may impact on the skirt 200, as the third obstacle locating device is moved forward. If the point of impact is between two sensors of the plurality, for example between first and second elongate wire fingers 6 and 7 as shown in figure 6, the flexible sheet material will depress, either the first sensor 6, the sensor 7, or both the first and second sensors, depending upon where the obstacle is in relation to the first and second sensors, ie. whether the obstacle is nearer the first sensor, nearer the second sensor, or midway between the two. A signal corresponding to the depression of the first and/or second sensors results at the plunger buttons in the handle 2.

By incorporation of the sheet material overlaying the sensors, in use, the sheet may sweep a path directly in front of the third obstacle locating device, and be capable of detecting any obstacle in a path transverse to the width of the obstacle locating device.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed

Claims

CLAIMS 1. An obstacle locating device comprising a one or a plurality of sensors arranged to sense obstacles; and an elongate shaft having an upper end adapted for holding by a person, and a lower end adapted for carrying the sensor(s).
2. A device according to claim 1 comprising one or more sensors for detecting when an obstacle lies to a first side of the device, for detecting when an obstacle lies substantially to a centre position of the device, and for detecting when an obstacle lies to a second side of the device.
3. A device according to any one of the preceding claims in which a said sensor is arranged to be actuated by a lever.
4. A device according to claim 3, wherein said lever comprises an elongate wire.
5. A device according to any one of the preceding claims, in which a plurality of said sensors are arranged in an array, the array lying in a line transverse to a main length of the shaft.
6. A device according to any one of the preceding claims in which the sensor comprises a flexible skirt which extends between first and second said sensors.
7. A device according to claim 6, in which said skirt is formed of a flexible sheet material.
8. A device according to claim 6 or 7, wherein said skirt is arranged to activate one or more said sensors when the skirt is deformed by collision with an obstacle.
9. A device according to any one of the preceding claims, comprising means for supporting the lower end of the shaft.
10. A device according to claim 9, wherein said means for supporting the lower end of the shaft comprises one or more wheels attached at the lower end of the shaft.
11. A device according to any one of the preceding claims, comprising an indicator means for indicating when a said sensor detects and obstacle.
12. A device according to claim 11, wherein said indicator means comprises a touch indicator, adapted to transmit a signal directly to a person's hand, for indicating when an obstacle is detected.
13. A device according to claim 12, wherein said touch indicator comprises one or a plurality of movable plungers.
14. A device according to claim 12 or 13, wherein said indicator means are located in a handle attached to an upper end of the shaft.
15. A device according to any one of claims 11 to 14, wherein said indicator means are capable of producing a signal in response to an obstacle sensed to a first side and/or a centre, and/or a second side of the device.
16. A device according to any one of claims 11 to 15, in which said indicator means comprises a handle, the handle having one or a plurality of movable plungers, each plunger capable of retracting into or extending from the handle, so as to either project from the handle, in which case the plunger(s) can be felt by a person as a bump in the handle, or to be retracted into the handle.
17. A device according to any one of claims 11 to 16, comprising three said indicators, one for receiving a signal from a left sensor, one for receiving a signal from a centre sensor and one for receiving a signal from a right sensor.
18. A device according to any one of the preceding claims, capable of being steered by tilting the device to the first side or to the second side.
19. A device according to any one of the preceding claims, in which a said indicator means comprises an audible alarm.
20. An obstacle locating device, the device comprising one or a plurality of sensors arranged to sense obstacles; an elongate shaft having an upper end adapted for holding by a person, and a lower end adapted for carrying the sensor(s); and a pair of wheels, wherein said sensor(s) is or are positioned between the wheels, the wheels being connected with a lower end of the shaft, a lower end of the shaft being positioned nearer one wheel of the pair of the wheels than the other wheel.
21. A device according to claim 20, in which said wheels are spaced apart in a direction transverse to the direction of the main length of the shaft.
22. A device according to claim 20 or 21, in which the lower end of the shaft is movable between a position nearer the one wheel, and a position nearer the other wheel.
23. A device according to any one of the preceding claims, in which said elongate shaft is adjustable, so as to be variable in length.
24. A device substantially as herein described with reference to figures 1 to 6 of the accompanying drawings.