Patent Description:
The present disclosure relates to the field of environment sensing. More particularly, the present disclosure relates to surface proximity detection and feedback for users of mobile devices, including mobility devices, mobile robotics, and remote control applications.

Collision of a mobile device (such as a wheelchair, walker and scooter, robot, and remote control device) with objects (including people and animals) within their environment may cause physical harm and property damage, both to the mobile device and the surrounding objects. Physical injury may be suffered by the driver/user of the mobile device and other people within the vicinity of the mobile device. In certain cases, a collision by a user may result in the loss of mobile device usage privileges.

Collisions with a mobile device can also have negative psychological consequences for mobile device users. Users may feel self-conscious about their driving abilities. Collisions may exacerbate a users' selfconsciousness and even cause embarrassment and reduce mobile device usage.

A system, device, and method for helping users avoid collisions with their mobile devices is desirable. <CIT> discloses a motorized wheel-chair that is equipped with one or more sensors for detecting obstacles. The detection method may be either radar or sonar (or both). An on-board computer processes these echoes and presents a visual or auditory display. With the benefit of these displays, the user issues voice commands (or exerts manual pressure) to maneuver appropriately the motorized wheelchair. One or more microphones pick up the sounds of the user's voice and transmit them to a computer. The computer decodes the maneuvering commands by speech-recognition techniques and transmits these commands to the wheelchair to effect the desired motion. In addition to speech recognition for decoding commands, voice (speaker) recognition is employed to determine authorized users. <CIT> discloses a collision avoidance system for a vehicle, wherein the collision avoidance system includes a warning device and a plurality of sensors that are arranged around the vehicle and that have sensing zones. Each of the sensors senses objects that are located in the sensing zone and generates sensor signals that are related to a distance between respective ones of the sensors and the objects in the sensing zones. Memory stores a plurality of profiles, which defines alarm limits for each of the sensors. A profile selection device allows selection one of the plurality of profiles from the memory. A vehicle collision avoidance controller communicates with the plurality of sensors and triggers the warning device when the sensor signal that is associated with one of the plurality of sensors exceeds a respective one of the limits in the selected profile. <CIT> discloses a direction indicator system that includes: an electromagnetic drive actuator that has a moving part that can slide back and forth, side to side, and diagonally; and a drive controlling unit that controls the sliding direction of the moving part, based on direction indicating information that is supplied from the outside. This document further discloses that this indicator system may be incorporated into a motorised wheelchair, the indicator system being used to indicate the presence of obstacles detected using a sensor. <CIT> discloses a wheelchair. The wheelchair of this document comprises propulsion means for at least two drive wheels, a wheelchair user movement indicator means that comprises means to indicate a forward, a backward and a rotation movement, at least one sensor system to detect at least one value referring to a surrounding free space, and a controller that comprises means to obtain a linear and a rotation movement component value, αjs, &bgr;js, from the data produced by the movement indicator means, and means to obtain the surrounding free space in a linear and in a rotation component, αs, &bgr;s, from the at least one value detected by the at least one sensor. The total linear and rotational movement, αT, &bgr;T, applied to the propulsion means are calculated as a combination of the linear and rotation movement component value, αjs, &bgr;js, obtained from the movement indicator means and the, at least one, value of the surrounding free space in a linear and rotation component, αs, &bgr;s.

The claimed invention provides a system according to independent claim <NUM>.

The claimed invention provides a method according to independent claim <NUM>.

The present disclosure describes a system, device, and method for helping a user avoid contacting surfaces with their mobile device. The system, device, and method sense the environment using one or more electronic sensors, process the sensor readings, and provide information to the user via one or more feedback modules about the proximity of surfaces within the environment. The sensors may be ultrasonic sensors. The system, device, and method may be used with mobile devices such as mobility devices to assist a user with moving, and with controlling robots. The sensors may be configured so their sensor cones cross at a point. Readings from the sensor(s) may be grouped according to detection zone(s) corresponding to one or more areas about a mobile device. A detection zone may have overlapping sensor cones. The detection zones may overlap one-another for a particular area. A computing module may control a feedback module according to detection zone readings. The feedback module may comprise an indicator for each detection zone. The indicator may be a vibration motor. The indicator may be a light. The computing module may set the colour of a light based on the proximity of surfaces detected within the corresponding detection zone.

In an embodiment of the present disclosure, the system comprises a sensor module comprising two or more sensors, each sensor configured to detect the proximity of an object to the sensor; a controller configured to control the sensors and analyze the data received from the sensors; and a user feedback module for providing information regarding the proximity of the sensors to an object based on the data analyzed by the computing module. The two or more sensors are retained by a sensor module such that the face of each of the two or more sensors (<NUM>) is at a different angle to the face(s) of the other sensor(s), and wherein the two or more sensors are positioned at an inward-facing angle to provide redundancy in the sensor readings.

The two or more sensor of the system may be ultrasonic sensors, each sensor comprising an ultrasonic transmit transducer and an ultrasonic receive transducer.

<FIG> shows a perspective view of a system <NUM> in accordance with an embodiment of this disclosure attached to a mobile device. The system <NUM> comprises a sensor module <NUM> and a feedback module <NUM>. The sensor module <NUM> is mounted on a location of the mobility device. <FIG> shows the sensor module <NUM> mounted on the bottom rear of a wheelchair. The feedback module <NUM> is mounted on the joystick of the wheelchair. The sensor module <NUM> is in communication with the feedback module <NUM>. The sensor module <NUM> is electrically connected to the feedback module to exchange data. The sensor module <NUM> may, however, have a wireless connection to exchange data wirelessly.

The sensor module <NUM> comprises a controller (also referred to herein as a computing module). The controller may be a central processing unit or processor. The feedback module <NUM> may also comprise a controller/computing module which may interface with the controller/computing module of the sensor module <NUM>.

Each of the sensors <NUM> in the sensor module <NUM> detects a surface of an object <NUM> if that surface is within the area or range covered by the respective sensor <NUM>. The sensors <NUM> each communicate their readings to the controller as data. The vicinity being monitored by the sensors <NUM> may be the area which is difficult for a user of a mobility device to view, such as the area behind the mobility device. <FIG> shows the sensor module <NUM> mounted to the back of an electrical wheelchair. Accordingly, the system <NUM> is setup to monitor the vicinity or area behind the wheelchair. The system <NUM> can also be configured to monitor the vicinity or areas in front of or on the sides of the wheelchair for users. These alternate or supplemental locations can be helpful for users who, for example, have low vision, including low peripheral vision and visual neglect.

The computing module receives the data from the sensor module <NUM>, analyzes that data, then communicates information to the user based on the data analysis using the feedback module <NUM>. In an embodiment, the data comprises information about the proximities of surfaces of the object <NUM> relative to the corresponding sensors <NUM>. That proximity information may be actual distances to the surfaces of the object <NUM> relative to the sensors <NUM> or some other reference point. The proximity information is used to communicate to the user of the mobility device the proximity of the object <NUM> relative to one or more reference points, such as one or more location on the mobility device. The sensor module <NUM> of <FIG>, for example, comprises multiple ultrasonic sensors <NUM> along its length. This permits detection of surfaces of object(s) relative to the entire width of the back of the wheelchair. When and the way this proximity information is communicated to the user depends on the feedback module <NUM> and/or computing module configuration. In <FIG>, the computing module combines the readings from the multiple sensors <NUM> to detect the locations of the surface of object <NUM> within three detection zones or regions of the back of the wheelchair: a left region <NUM>, a right region <NUM>, and a middle region <NUM>. The computing module then sends data, such as RGB values and pulse intensity/duration, to the feedback module <NUM> corresponding to each zone or region. The data is sent via the wire connection, but may be sent wirelessly.

<FIG> shows a top view of the system <NUM> of <FIG> mounted to a mobility device, with feedback modules <NUM>, <NUM> in greater detail. The feedback module <NUM> comprises a light module <NUM>. The light module <NUM> comprises a left light <NUM>, a right light, <NUM>, and a middle light <NUM>. The lights may be light emitting diodes (LEDs). Each LED may show the status to a user for a particular detection zone being monitored by the sensor module <NUM>. The colour of each of the lights <NUM>, <NUM>, <NUM> may correspond to a proximity range within which the sensors <NUM> detected the surfaces of object(s) in each of the detection zones <NUM>, <NUM>, <NUM>. The proximity ranges may be relative to a location on the sensor module <NUM>, such as the receiver of the sensor <NUM>. For example, the entire surface of the planter <NUM> of <FIG> is in the middle detection zone <NUM>. In a configuration of the controller, this may cause only the middle light <NUM> to illuminate a particular colour. The left light <NUM> and the right light <NUM> would not illuminate because there is no object within the corresponding detection zone <NUM>, <NUM>. As further described below, the computing module aggregates the sensor readings into a particular output.

The colour of the middle light <NUM> depends on the minimum of the distances between the sensors <NUM> monitoring the middle region <NUM> and the surface of the planter <NUM>. If the distances decrease, the middle light <NUM> may change colour in real-time (or close to real-time) to indicate to a user that the surface of the planter <NUM> is getting closer. For example, the colour sequence may be green for objects that are relatively far away, yellow for objects that are midrange, and red for objects that are very close, relative to a point on the sensor module <NUM> corresponding to the detection zone. This point is a proxy for a point on the mobility device. In an embodiment, the controller comprises a memory with a mapping of proximity/distance range(s) to light colour(s).

In an embodiment, the mapping is as follows:.

The applicant has found this three light display to be one way to represent to the user the environment within a <NUM>-degree field of view of the mobility device. This light system indicates to the user whether an object is present within the detection areas, how close the object is to the mobility device, and the location of the object relative to the mobility device.

The feedback module <NUM> also comprises mode lights <NUM>, <NUM> and a mode switch <NUM>. The mode switch <NUM> is used by a user to change between three different system modes: short range, long range, and off. The mode lights <NUM>, <NUM> are illuminated according to the system mode. In short range mode, only light <NUM> is illuminated/on. In long range mode, both lights <NUM>, <NUM> are on. In off mode, none of the lights are on.

It is important for a user to have a persistent indicator of whether the system <NUM> is on or off. This is especially true when the lights of the light module <NUM> are off when no object is within the sensor <NUM> zones. If a user thinks the system <NUM> is on when it is actually off, the user could mistakenly think that no object is within the vicinity of the sensor module <NUM>. This could result in injury or damage to property.

It can also be helpful to a user to have a long range system mode and a short range system mode which can be selected depending on the user's environment. In long range mode, the system <NUM> is configured to have greater/larger object proximity thresholds than in short range mode. In other words, in long range mode, the system <NUM> may monitor a further distance away from the sensors <NUM> than in short range mode. By contrast, in short range mode, the system <NUM> may provide a user with greater precision information as to the distance of an object from the sensors <NUM>. Long range mode would be helpful with detecting objects in high-speed environments such as sidewalks and roadways. If objects are approaching at a greater speed, the user needs to be alerted when those objects are a further distance away so that the user has sufficient time to react. Indeed, the system, device and method of the present disclosure may be used in applications to detect objects moving towards or away from a stationary mobile device is stationery. Short range mode would be helpful with detecting objects in a close-proximity environment such as a house or an office. In such environments, objects are typically not approaching the mobility device at a high speed. Rather, the user needs to have greater precision information so that they can navigate their mobility device through tight spaces and next to objects which are very close to the mobility device, and potentially on opposite sides of the device at the same time. For example, in long range mode, the system <NUM> may be configured to illuminate the middle light <NUM> red for any object that is within <NUM> feet or less of a point of the sensor module <NUM>. In short range mode, however, the system <NUM> may be configured to illuminate the middle light <NUM> green for any object between <NUM> and <NUM> feet, yellow for any object between <NUM> inches and <NUM> foot, and red for any object less than <NUM> inches, away from a point on the sensor module <NUM>. Many mobility devices are unique in that they need to be operated in different types of environments and can transition between different environments quickly and seamlessly (i.e. entering a building from the street).

In an embodiment in accordance with the present disclosure, the user may configure a distance threshold corresponding to a light colour for a particular detection zone by navigating the sensor mobility device to a select distance from a reference object for the detection zone, and indicating to the system <NUM> (such as pressing a button on the feedback module <NUM>) that the selected distance is the new threshold distance (or boundary) for that detection zone and mode.

The mode switch <NUM> may be a button that can be pressed to cycle through the modes. A press can be functionally easier for a greater number of users, since some users may not have good motor control of their hands to move a particular switch between locations. A button, however, allows the users to press with whatever body part is feasible - including their head. This switch <NUM> may be physically located on the feedback module <NUM> or be connected through a wire to the feedback module <NUM> to allow users to plug in their own switches (e.g., buttons or proximity switches) that they might be more comfortable with using and allow for placement in an alternate preferred location.

The system <NUM> also comprises a second feedback module <NUM>. The second feedback module <NUM> is a haptic module to provide haptic feedback to the user. The haptic module <NUM> may comprise one or more vibrator motors or other types of electronic devices which produce a vibration, generally referred to herein as vibration devices. The vibration devices are turned on and off to provide touch-based information to the user about the environment being sensed by the system <NUM>.

In an embodiment, the haptic module <NUM> comprises three vibration motors: a left vibration motor <NUM>, a right vibration motor <NUM>, and a middle vibration motor <NUM>. The vibration motors are located on the seat cushion of the wheelchair. The vibration motors <NUM>, <NUM>, <NUM> may be located, however, in any location such as on the back rest, and the arm rest. The locations of the vibration motors may be selected by the user. The locations may be dictated by the user's needs. The on/off sequence, intensity, and/or duration of the vibration motors <NUM>, <NUM>, <NUM> depend on the sensor <NUM> data and the configuration of the controller. The control of each of the vibration motors <NUM>, <NUM>, <NUM> may correspond to objects within a particular detection zone or region <NUM>, <NUM>, <NUM> covered by the sensor module <NUM>.

The haptic module <NUM> may be controlled by the computing module. In an embodiment, a vibration motor cycles on for a brief period when a particular event occurs or a condition is met for the detection zone <NUM>, <NUM>, <NUM> corresponding to the vibration motor. The event or condition may be the detection of a surface of an object at a threshold distance. The vibration cycle may last <NUM> second. The event or condition may be the surface of an object getting incrementally closer, such that at each increment the vibration produced by the vibration motor increases in intensity and/or duration. In an embodiment, the vibration may be timed to occur with the changing of the colour of the corresponding light in the light module <NUM>. For example, as a user reverses their wheelchair closer to the planter <NUM>, the middle light <NUM> changes from green to yellow when the planter is a particular threshold distance from the sensors <NUM> monitoring the middle detection zone <NUM>. At the moment or the distance threshold at which the middle light <NUM> changes colour, the middle vibration motor <NUM> may turn on for <NUM> second. In this way, the vibration motor provides non-visual feedback to the user about a change in the environment being monitored by the system <NUM>. Although transitory, this non-visual feedback can be sufficient to prompt the user to look at the light module <NUM> to get a better sense of proximity to the object relative to the different locations of the mobility device. The light module <NUM> provides persistent feedback to the user. The combination of the haptic module <NUM> with the light module <NUM> allows a user of a mobility device to look away from the light module <NUM> but be prompted to look back at the light module <NUM> when an object approaches. Although the vibration motor <NUM>, <NUM>, <NUM> predominantly creates a touch-based signal, it may also provide an auditory signal to the user. The combination of a visual feedback module and a haptic feedback module can allow the user to develop cognitive adaptations to the feedback stimulus. In this way, a user may eventually perceive their senses as extending beyond their physical body and reaching into the mobility device, itself. Indeed, feeling a vibration can seem very similar to brushing up against an object. Vibrations can, accordingly, be a very intuitive way to provide information to a user about their environment. Vibrations may be processed by a user more quickly than a visual stimulus, alone.

The feedback module <NUM> also comprises a vibration control <NUM>. In an embodiment, the vibration control <NUM> is a knob which is turned to a particular setting to increase or decrease the intensity of the vibrations of the vibrator module <NUM>. Users may want to change the intensity of the vibrations periodically. This can be helpful when changing between different environments or when wearing different thicknesses of clothing. For example, a user may want a high intensity vibration setting when using their mobility device in a noisy or bumpy environment, such as a mall or a bumpy road, respectively. A user may want a low intensity vibration setting, however, when using their mobility device in a quite or smooth-rolling environment, such as a library or a carpeted office, respectively. Some users may also be sensitive to vibrations or have changing sensitivities to vibrations. For example, a user with cerebral palsy may have a spastic episode in response to higher-intensity vibrations. The level of vibrations that triggers a spastic episode in a particular user may also vary from day-to-day.

The computing module may comprise a memory containing a program having instructions which are executed by a processor. The computing module may communicate the results of the analysis to a feedback module <NUM> as data. Based on the data from the computing module, the feedback module <NUM> may provide a user of the system <NUM> with information about the proximity and/or location of objects within the vicinity of the system. The system/device may be powered by an internal or external battery, or the power source of the mobility device, itself, through existing or custom ports.

<FIG> show various views of a sensor module <NUM> in accordance with an embodiment of the present disclosure. The sensor module <NUM> comprises a housing <NUM> and one or more sensors 304a, 304b, 304c, 304d, 304e. The sensor module <NUM> may also comprise a sensor support structure <NUM>. The sensor support structure <NUM> is for retaining the sensors 304a-e in a certain positions within the housing <NUM>. The sensor support structure <NUM> may form and be integrated with the housing <NUM> such that the housing <NUM> and the sensor support structure <NUM> are one integrally-formed piece.

The sensor module <NUM> may contain an internal processor, and/or an interface for communication with an external processor. The sensor support structure <NUM> holds each of the sensors 304a-e at a particular angle relative to the sensor module <NUM> and each other, respectively. The support structure <NUM> may be configured to permit the user or an installer to adjust the angles of the sensor 304a-e from time-to-time. In an embodiment, servo motors are mechanically connected to the sensors so that their angles may be independently adjusted by the user or automatically by a processor according to a particular algorithm. The ability to adjust the angles after installation of the system <NUM> on the mobility device may assist with compensating for the tilt of the mobility device or sensor module <NUM>, for example, to help ensure that the angle of the sensors 304a-e to the ground plane remains consistent.

The sensors 304a-e in the sensor module <NUM> may be configured, arranged, or positioned in the sensor module 300in such a way so as to create one or more detection zones <NUM>, <NUM>, <NUM> about the sensor module <NUM>. The detection zones <NUM>, <NUM>, <NUM> divide up a portion of the area around the sensor module <NUM> that all of the sensors 304a-e, collectively, can detect objects within.

In accordance with the sensor module <NUM> of <FIG>, the ultrasonic sensors 304a-e are arranged to form three detection zones <NUM>, <NUM>, <NUM>. Each sensor may be able to detect the surface of an object within a cone-shaped volume, the tip of which commences at or close to each sensor face, and the cone of which extends outward from the face of the sensor. This is also referred to herein as a sensor cone. Although many surfaces may fall within a sensor cone for a particular ultrasonic sensor, the ultrasonic sensor may only identify, record, and/or communicate the surface closest to the sensor face. Sensors 304e and 304d are each positioned on opposite sides of the sensor module <NUM>. Sensors 304e and 304d may each be positioned at an angle of <NUM> degrees relative to the back plane <NUM> of the sensor module <NUM>, the sensors each facing outwards. Sensors 304a and 304c are positioned on the front of the sensor module <NUM>. Sensors 304a and 304c may each be positioned at an angle that is anywhere between <NUM> degrees and <NUM> degrees relative to the back plane <NUM> of the sensor module <NUM>. In an embodiment, sensors 304a and 304c are each angled inward by <NUM> degrees. Sensor 304b is positioned on the front of the sensor module <NUM>. Sensor 304b may not be angled in any direction relative to the back plane <NUM> of the sensor module <NUM>.

As shown in <FIG>, multiple ultrasonic sensors 304a-e with overlapping cone-shaped volume coverage of a particular area may be used to detect the surface of an object in a detection zone. The overlapping areas of coverage by the sensors can provide increased reliability through sensor reading redundancy. A single sensor may give inaccurate readings, such as about the existence and/or distance of a surface of an object in its detection area, depending on the position and/or angle of the sensor face relative to the object, the shape of the object, the height of the object, and/or the material of the object. Individual sensors my also fail. Individual sensors may also periodically have incorrect readings due to electro-magnetic interference. Inexpensive ultrasonic sensors can be prone to incorrect readings and poor quality readings, especially for surfaces that are at an angle that is not parallel to the face of the sensor. Overlapping sensor detection areas, however, can help provide redundancy to reduce the effect of one sensor having an incorrect reading. Using multiple sensors, each sensor with its face at a different angle from the other sensor faces, can help detect surfaces at a variety of angles. Overlapping sensor detection areas can also increase the total area or volume viewable by all of the sensors, collectively. The total horizontal planar area within which the sensors can detect an object (also referred to as viewable area), collectively, may be <NUM> degrees relative to the backplane <NUM> of the sensor module <NUM>. For example, the readings from sensors 304e may be used to detect objects within detection zone <NUM>; the readings from sensors 304a, 304b, and 304c may be used to detect objects within detection zone <NUM>; and the readings from sensor 304d may be used to detect objects within detection zone <NUM>.

The number of sensors used in the system may depend in part on the type(s) of sensor(s) being used, and/or the information required. For example, a single LIDAR sensor may be used to obtain detailed information about the distances of all surfaces within a full <NUM> degree field of view. LIDAR sensors, however, may be <NUM> to <NUM> times the cost of an ultrasonic sensor. In an embodiment, a plurality of inexpensive ultrasonic sensors are used in the system <NUM>. Even though multiple ultrasonic sensors are used, the cost of those sensors, collectively, may still be significantly less than a single LIDAR sensor. Although significantly less expensive, using the multiple ultrasonic sensors in a particular configuration may still provide the data that is required to notify the user about objects within their vicinity at the necessary resolution.

In an embodiment, the computing module is configured with an algorithm which assigns one or more sensors to a selected detection zone. The algorithm might identify the minimum of distance/proximity reading between all sensors assigned to the detection zone. That minimum distance/proximity reading may be used as the single/unitary value to control the portion of the feedback module(s) providing information to the user about the corresponding detection zone. The algorithm may smooth the sensor readings (e.g. by taking a rolling average for a period of time, or waiting for at least a certain number of readings within a new distance threshold) to help ensure that if an object is in the middle of two distance thresholds, the feedback module(s) do not rapidly switch back and forth between two ranges. This smoothing may only occur when the current distance reading is greater than the previous reading. If the current distance reading is smaller than the previous distance reading, no smoothing may be desired so that the user is immediately notified of an object that may be closer. Such a conservative approach to sensor reading filtering can be important for mobility applications where physical harm or property damage can result if an object is actually closer than the distance identified to the user.

The sensor module may be attached at various locations on a mobility device. For example, the sensor module <NUM> may be attached to the base of the back of the mobility device (as shown in <FIG>), or the top of the back portion of the backrest of the mobility device. Being able to attach the sensor module <NUM> to different locations of a mobility device increases the likelihood of finding a location that permits multiple sensors 304a-e to have an unobstructed view of a select area of interest. There are many types of mobility devices. For example, mobility devices may include wheelchairs, motorized wheelchairs, scooters, walkers, devices for assisting users with standing from a seated position and walking, canes, bicycles and motorized bicycles. Having the flexibility to mount the sensor module at different locations on a particular mobility device helps accommodate the different structures of mobility devices and/or the unique physical requirements of the user. Examples of potential locations at which to mount a sensor module <NUM> include, but are not limited to, the backrest, base, seat pan, arm rest, leg rests, or other accessories such as mounts and trays of a mobility device. The sensor module <NUM> may be fastened to the mobility device using one or more of the following: fabric fasteners/straps, adhesives, and rigid couplers. The system <NUM> may comprise spacers and/or supports to help position the sensor module <NUM> on the mobility device, and set the attitude of the sensor module <NUM> relative to the mobility device.

The system, device, and method of the present disclosure may also be used in other applications which have similar object detection requirements, such as remote controlled robots such as telepresence robots. The sensor module may be attached or mounted to a robot to provide feedback/information to the user of that robot to help the user navigate the robot around obstacles within the vicinity of the robot. Similar to a mobility device application, robots may need to be navigated through obstacles which are very close in proximity to the robot. The user may be operating the robot locally or remotely. The system, device and method of the present disclosure may help augment or supplement other environment sensing equipment, such as a video monitor.

Users of mobility devices may need supplemental or augmented information about the environment behind their mobility device. A mobility device may physically restrict a user from rotating their body relative to the mobility device to see what objects are behind the mobility device. A user may also not have the physical ability to rotate their body relative to the mobility device. Even if a user can rotate, the mobility device (or objects hanging off the mobility device such as a backpack) may partially or completely block the user's view, especially the area/region in very close proximity to the back of the mobility device. A user may also have visual impairment which would further reduce the user's ability to see what is behind their mobility device. In an embodiment in accordance with this disclosure, a sensor module <NUM> is mounted to the back of a mobility device to monitor the area behind the mobility device. Users of mobility devices can benefit from information about the environment behind their mobility devices. Such information can, for example, help a user reverse their mobility device. Users typically find themselves in environments with their mobility devices where multiple objects are quite close together. In such environments it may not be possible for the user to turn their mobility device around. Instead, the user must reverse their mobility device through the environment, navigating the objects which are in close proximity and behind the mobility device. Users may also need to reverse into or through a particular portion of an environment (such as through a doorway) because the mobility device is more maneuverable when reversing as compared to going forward. This is similar in concept to needing to reverse a car to parallel-park.

The system <NUM> may also be able to alert a user to a potential security threat behind their mobility device. Users of mobility devices may have an increased risk of theft. It is common for mobility device, and especially wheelchair users, to hang a backpack containing person items on the back rest of their mobility device. This makes it easier for someone to remove an item from the backpack without the user's knowledge. For example, the system <NUM> may alert the user to a person behind their mobility device, the proximity of that person, and/or whether the person is approaching or moving away from the back of the mobility device. If the system <NUM> detects a person that is close to the back of the mobility device and continuing to approach the mobility device, this alerts the user that the person may be attempting to steal their belongings or intentionally make contact with the user.

Navigating a mobility device through a doorway can be difficult for a user, irrespective of whether it is done in forward or reverse. Navigating a doorway with a mobility device can be difficult for a number of reasons. For example, a doorway has solid walls which are opposite to each other to define a narrow space through which to pass. The widths of doorways are typically set for a person without a mobility device. Mobility devices are typically much wider than a standard person. Doorways may also have doors which consume a portion of the space within a doorway which would have otherwise been available.

In accordance with an embodiment of the present disclosure, the system <NUM> is used to help a user navigate their mobility device through a doorway. This may comprise helping the user to better align their mobility device with a doorway before the user passes their mobility device through the doorway. In an embodiment, the system <NUM> is first put into short range mode. The user then navigates their mobility device towards the doorway. The sensor module detects the sides of the doorway within the detection zones as they approach, and the system <NUM> alerts the user to the mobility device's position relative to the sides of the doorway through the haptic feedback module <NUM> and the light module <NUM>. A user knows they are properly aligned to pass through a doorway without a collision with the doorway when both the left light <NUM> and the right light <NUM> of the light module <NUM> are illuminated the same colour, and the middle light <NUM> is of a colour that indicates that there is sufficient open space in the direction the user needs to travel. If both side lights are illuminated the same colour, this indicates to the user that the sensors for the left detection zone <NUM> and the right detection zone <NUM> are approximately the same distance to the left and right sides of the doorway, respectively. For example, if both left and right lights <NUM>, <NUM> are red, this indicates that the sensor module (and the corresponding mobility device) is relatively centered within the doorway and likely not going to hit either side. By contrast, if the left light <NUM> is red but the right light <NUM> is yellow (or whatever colour is mapped to a greater distance threshold range), this indicates that the sensor module <NUM>, as a proxy for the mobility device, is misaligned with the doorway: it is too close to the left side of the doorway and not sufficiently close to the right side of the doorway. The user then knows to bring the right side of the wheelchair closer to the right side of the doorway to better align and avoid a collision with the left side of the doorway. Where the lights are LEDs, a user can more easily see the colour of the lights in their peripheral vision. Having different shaped cut-outs for the lights in the top of the feedback module can also help a user differentiate between the lights, particularity when all of the lights are not illuminated at the same time. The combination of LEDS and different shaped cut-outs can help a user obtaining object proximity information by using their peripheral visions without looking directly at the lights, themselves. Being able to use peripheral vision to receive information from the system <NUM> can enable the user to use their direct vision to also help with navigating the doorway (or some other environment).

The vibration module <NUM> can also provide information to the user to help the user navigate through the doorway without a collision. A user knows they are properly aligned to pass through a doorway if the left vibration motor <NUM> and the right vibration motor <NUM> each provide the same number of vibration cycles, vibration durations, and/or vibration intensities. The same number of vibration cycles, the same vibration durations, and/or the same vibration intensities means that each of the left side of the doorway and the right side of the doorway are within the same range thresholds for the left and right detection zones <NUM>,<NUM>. In other words, neither side of the doorway is too close or too far away from the sensor module <NUM> such that one side of the mobility device will hit the doorway frame. If there are unequal number vibration cycles, vibration durations, or vibration intensities between the left and rights vibration motors <NUM>, <NUM>, the user knows to navigate the mobility device in the direction corresponding to the side which has had a lower number of vibrations cycles, vibration duration, or vibration intensity. This is because the sensors for that detection zone have not come sufficiently close to the corresponding side of the doorway frame. In other words, the user's goal is to cause the left and right vibration motors to produce the same number of vibration cycles, vibration durations, and/or vibration intensities.

In another embodiment, the system <NUM> is used to navigate a mobility device closer to an object without collisions so that the user may interact with the object or something close to the object. For example, the system <NUM> may be used to align a mobility device adjacent to a wall without collision so the user can reach a switch/button on the wall. To make it easier to reach a switch or button (e.g. such as an elevator call button) on a wall, users typically align their mobility device so that the side of the device faces (is parallel to) the wall. It can be too far for a user to reach a switch/button when the front of the wheelchair faces the wall. It can be difficult, however, for a user to align their mobility device so the side is parallel to the wall. A user might have difficulty assessing how far away a switch/button is while trying to move their mobility device to be parallel with a wall. This difficulty could be due, in party, to lower peripheral vision. In some cases, the mobility device is too far away. In other cases, the mobility device collides with the wall. In an embodiment, the system <NUM> is configured to provide an indication to the user via a feedback module <NUM> when the mobility device is parallel, and sufficiently close to, a wall for the user to reach the switch/button on the wall. In an embodiment, a side light is illuminated a particular colour on the feedback module.

In accordance with the sensor module <NUM> shown in <FIG>, the sensor module <NUM> is mounted to a part of the mobility device (such as the lower backrest of a mobility device) using a flexible cloth strap and buckle. The cloth strap passes through a strap cavity <NUM> defined by the back of the sensor module housing <NUM>.

<FIG> shows a perspective view of an embodiment of a sensor module <NUM> in accordance with the present disclosure. The sensor module <NUM> is similar to the sensor module <NUM> shown in <FIG>. The sensor module <NUM> comprises a strap cavity <NUM> defined by the sensor module housing <NUM>.

<FIG> shows various views of another embodiment of a sensor module <NUM> in accordance with the present disclosure. The sensor module <NUM> is similar to the sensor module <NUM> shown in <FIG>, the difference being that the sensor module <NUM> is formed from predominately plastic components. The plastic components may be injection molded.

<FIG> shows a perspective view of a sensor module <NUM> in accordance with an embodiment of the present disclosure. The sensor module <NUM> similar to the sensor module <NUM> shown in <FIG>. The sensor module <NUM> comprises a strap <NUM> which passes through a strap cavity <NUM>.

<FIG> shows an exploded perspective view of a sensor module <NUM> in accordance with an embodiment of the present disclosure. The sensor module <NUM> is similar to the sensor module <NUM> show in <FIG> comprising predominantly plastic structural components. The sensor module <NUM> comprises a housing made of two-halves: a top half housing <NUM> and a bottom half housing <NUM>. Each of the housing halves <NUM>, <NUM> comprises a portion of the sensor support structure 706a,b integrally formed therewith: a top half 706a sensor support structure and bottom half 706b sensor support structure. The sensor support structure <NUM> comprises a pattern of fins <NUM> defining half-moon cut-outs that hold the various internal sensors <NUM> in place. The back plate 712a,b of the sensor module <NUM> is also in two halves, each half integrally formed with the corresponding housing portion.

<FIG> shows an exploded perspective view of a sensor module <NUM> in accordance with an embodiment of the present disclosure. The sensor module <NUM> is similar to the sensor module <NUM> shown in <FIG>. The sensor module <NUM> comprises predominantly sheet-metal or sheet-based structural components. The sensor module <NUM> comprises a top plate <NUM>, a bottom plate <NUM>, and a back plate <NUM>. The sensor module <NUM> also comprises a sensor support structure <NUM> which may be a sheet of metal folded at different points along its length. The support structure <NUM> is placed between the top plat <NUM> and the bottom plate <NUM>. The sensors <NUM> are then inserted into retaining holes <NUM> defined by the support structure <NUM>. The components may be held together using fasteners (such as screws and bolts) and/or an adhesive.

<FIG> show various views of another embodiment of a sensor module <NUM> in accordance with the present disclosure. The sensor module <NUM> contains only one sensor thereby making it smaller. The sensor may be a ultrasonic sensor comprising a separate transmitter and receiver. The sensor module <NUM> comprises a housing <NUM>. The housing <NUM> defines one opening <NUM> for a single sensor <NUM>. Rather than a single large sensor module, multiple smaller sensor modules <NUM> may be used together to detect surfaces with a particular area. For example, multiple smaller sensor modules <NUM> may be used to accommodate certain physical features on a mobility device which inhibit the use of a larger sensor module. A physical feature may prevent the larger sensor module from being properly positioned on the mobility device. A physical feature may also block a sensor from viewing a particular area. Multiple smaller sensor modules <NUM> may also be used to detect objects around a mobility device. The smaller sensors modules <NUM> can also be configured and coordinated to divide an area around the mobility device into one or more detection zones. The boundaries of these detection zones may not necessarily being contiguous with one another. Multiple smaller sensor modules <NUM> may also be combined together and/or with a larger senor or multiple sensors (such as the sensor module <NUM>) in one system to help increase the area monitored by the sensor modules, collectively, and/or to increase the system reliability by overlapping the areas monitored by each sensor. For example, a smaller sensor module <NUM> may be placed at a user's head level to monitor for high objects (such as tables) which may be difficult to detect with just a sensor module, alone. The sensor modules <NUM> may connect into a central hub containing a processor and/or the computing module. The central hub may reside in a large sensor module <NUM> or outside. The readings from each of the multiple sensor modules <NUM> are analyzed by the processor in accordance with certain instructions to obtain aggregate data representing the proximity of an object to the sensor module. The sensor module location may be a proxy for a location on the mobility device. That proximity data is then communicated to a user using a feedback module.

<FIG> shows an exploded view of the sensor module <NUM>. The housing has a top half 902a and a bottom half 902b. The sensor module <NUM> also has a back plate <NUM>. The housing 902a,b and back plate <NUM> retain the sensor <NUM> in a proper orientation.

The sensors used with a sensor module may be any one or more types of sensors that can detect the proximity of a surface of an object to the detector of the sensor. The type(s) of sensors used in a sensor module may depend on the application for which the sensor module is being used. Different types of sensors may be incorporated into a single sensor module.

In an embodiment, a sensor may be ultrasonic sensors. Ultrasonic sensors may be used when the application is for detecting objects or surfaces within the vicinity of a mobility device. In a mobility device application, the system may be required to determine the distance of a surface to a mobility device when the mobility device is within a range of less than <NUM> meters from the object or surface. The system may need to be able to detect the distance of a surface of an object within a margin of error of <NUM> to <NUM> centimeters. The system may also be required to function outdoors where lighting, sound, and electro-magnetic interference may reduce the reliability of readings from certain types of sensors. Since a mobility device typically moves relative to objects, and the system may be used to help a user navigate objects within their surroundings/environment, the system may be required to quickly detect changes in the distance between the mobility device and an object/surface. The system may be required to detect changes in the distance in real-time. The sensors may also need to be relatively inexpensive by capable of being configured to provide a reliable outcome. Ultrasonic sensors may be better suited than other types of sensors to achieving the above-noted requirements.

In an embodiment, the ultrasonic sensor of the sensor module comprises a transmission transducer (also referred to as transmitter) and a separate reception transducer (also referred to as receiver). Having separate transmission and reception transducers may help improve the minimum distance the sensor is able to detect, and the rate at which changes in the distance of an object or surface to the sensor is detected. While it may be possible to use a single transducer for both transmitting an ultrasonic signal and detecting the reflection of that signal off of a surface or an object, a single transducer may result in a lower rate of distance detection and a higher minimum distance that can be detected. This is because in a single transducer sensor, the transducer alternates between transmitting an ultrasonic signal (transmitting mode) and receiving an ultrasonic signal (receiving mode). When transitioning between the transmitting and receiving modes, the transducer must be allowed to settle for a period of time before it is capable of receiving the ultrasonic signal reflected from the surface. The closer an object is to the sensor, the less time the sensor has to settle before needing to transition the sensor to receiving mode to detect the reflection of the transmitted signal. The smallest distance that is possible to detect with a single transducer may make the single transducer sensor undesirable if the application requires detecting obstacles at a close range such as in certain mobility applications.

A sensor may in the alternative be, or comprise, one or more of an infrared sensor, Lidar, radar, a electromagnetic sensor, an accelerometer, or gyroscopic sensors. Using different or multiple types of sensor in sensor module(s) forming part of the system may help improve accuracy, reliability, and/or the functionality of the system for certain applications. Depending on their construction, a proximity sensor may be better suited to detecting surfaces of objects in specific distance range or materials.

In an embodiment in accordance with <FIG>, five ultrasonic sensors 304a, 304b, 304c, 304d, 304e (each sensor comprising a transmitter transducer <NUM> and a separate receiver transducer <NUM>) are used to create three detection zones. The detection zones collectively covering a <NUM>-degree horizontal plane around the sensor module <NUM>. The detection zones are a left detection zone <NUM>, a middle detection zone <NUM>, and a right detection zone <NUM>. The detection zones may overlap. The sensor module <NUM> may be positioned on a mobility device as shown in <FIG> so that the detection zones cover the area at the rear of the mobility device. The ultrasonic sensor is suitable in this application as the types of material that are acoustically reflective and detectable by ultrasonic sensor are typically hard and desirable to be avoided by a mobility device. Hard surfaces typically cause more damage when contacted by a mobility device. By contrast, the types of materials that are not acoustically reflective (and therefore invisible to the ultrasonic sensor) are soft and cloth-like materials, which users are less concerned about avoiding since they typically cause less damage when contacted by a mobility device. Put another way, acoustically reflective, hard, materials are highly visible to ultrasonic sensors, and are also potentially damaging in the case of a collision.

The sensors 304a-e may be positioned in the sensor module <NUM> according to the angle defined by their specific field of view. If each sensor has is a narrower field of view, the angle of each sensor face relative to each other may be greater to ensure a particular total area is covered, even if there are blind spots within that total area. This may also reduce the overlap of sensor cones. On each end of the sensor module <NUM>, a sensor 304e, 304d may point sideways such that the forward-most limit of its field of view is parallel to the plane defined by the back of a seat of a mobility device. All of the other sensors would be angled accordingly to give <NUM> degrees of vision area. One sensor 304b may be located in the middle of the sensor module <NUM>, to view the area directly behind the mobility device. The two remaining sensors 304a, 304c may be located next to the outward-facing sensors 304e, 304d, but may be pointed inward by an angle selected to give a reasonable balance of redundancy directly behind the mobility device, and consistent angular coverage. The two outer pairs of sensors 304e, 304d may be spaced approximately <NUM> apart and the housing <NUM> may be approximately <NUM> wide to occupy about <NUM>% the width of a mobility device.

The computing module may be contained within the housing of the sensor module, or within a separate housing to be attached elsewhere to a mobility device. The computing module may include extra ports to allow for additional sensor modules to be connected. Where the computing module is external to a sensor module, all sensor modules may be connected via such ports. The computing module may also contain ports to be used by one or more feedback modules. The computing module may also consist of a wireless transmitter/receiver to use a wireless communication protocol (such as Bluetooth) to send/receive wireless signals and communicate with all of the electronic devices that are part of the system, or other electronic devices.

In an embodiment, the computing module receives data from one or more sensor modules, analyzes the data, and controls the feedback module in accordance with the analyzed data. The output to the feedback module may be based on adjustable feedback module parameters.

In an embodiment, the computing module receives un-processed (raw) sensor data from the sensors within the one or more sensor modules. The raw data is then normalized using algorithms that include noise filtering. The algorithms may check for local temporal coherence (the correlation or relationship between data collected at different moments in time by the same sensor) in order to eliminate incorrect data. The algorithms may comprise a low-pass filter, which can help eliminate sensor reading spikes and other anomalies. The algorithms may use some adjustable variables in order to recognize unwanted or incorrect data. Machine learning algorithms may also be used to learn sensor models and predict system accuracy.

Data from sensors that are observing or allocated to monitor the same detection zone are then combined by the computing module in a manner so as to assess the proximity of the closest obstacle or surface within that detection zone. Data from sensors positioned to predominantly monitor other detection zones, but which have overlapping coverage with the detection zone, can also be used. Global temporal and spatial coherence (within each detection zone, and/or across multiple sensors and/or detection zones) can then be used to achieve a single object surface proximity value for each detection zone. In the case that different types of sensors are used, a weighted combination of sensor values may be used. Final object surface proximity values for each detection zone may then be communicated to the feedback module based on adjustable parameters (e.g., intensity and colour mappings).

The computing module may comprise a memory. The memory may store adjustable setting parameters. The parameters may relate to the assignment of sensors in the sensor module to detection zones, and affect how readings from those sensors are analyzed/combined, and the actions to take in response to the date analysis. The computing module may also store parameters relating to the feedback module(s), including which modules are enabled and disabled, distance ranges, mappings of these ranges to feedback parameters (e.g., light intensity, colour corresponding to distance threshold ranges, audio type, audio volume, audio frequency, vibration duration, vibration intensity, intervention type).

The computing module may also be configured or programmed to comprise multiple modes that can be toggled between, each mode with its own set of adjustable distance threshold ranges that trigger warning indications and danger indications. Each mode can thus define the proximity values corresponding to the type of feedback provided to the user via the feedback module(s).

In an embodiment, a first mode may be configured such if the mobility device is a distance of between <NUM> and <NUM> from an obstacle or surface, a warning indication is provided, while at distances equal to or lesser than <NUM>, a danger indication is provided. A second mode may be configured to provide warning indications when the mobility device is a distance of between <NUM> and <NUM> from an obstacle or surface, and danger indications at distances lesser than or equal to <NUM>.

The computing module may be programmed to comprise persistence variables which determine how long an obstacle is reported to a user via the feedback module to be in a detection zone after the object has left the zone. In addition, a block or feature of the feedback module corresponding to a particular detection zone might be illuminated based on the detection of a surface or object in an adjacent detection zone. This would help account for the motion model and/or dimensions of the mobility device. For example, even if an object is detected as being present in a middle zone and the left and right zones are determined to be free of any obstacles, the feedback module may show all three zones to comprise obstacles since a mobility device might not be able to safely navigate to the left or right zones at full speed without hitting the obstacle that is in the middle zone.

Parameters and/or settings may be configured or selected directly on the computing module, and/or by using a physical switch, a wireless switch (e.g., using a smart phone application), and/or a voice-activated mechanism that relays the information to the computing module.

Data collected and processed by the computer module may be saved to a computer-writable medium and/or may be transmitted wirelessly and/or uploaded to a server connected to the internet (cloud). Such data can be used for logging and/or monitoring purposes. For example, such data can be used to present information regarding nearcollisions, average distance to obstacles, proximity to obstacles, location of obstacles, the mobility device user's driving behaviour, etc. In one embodiment, proximity and locations of obstacles are display in a web or smart phone application.

A feedback module may provide a variety of types of feedback to the user, including, visual, audio, and/or haptic feedback. A feedback module may be configured to provide different information to a user for each type of feedback. For example, the feedback module may provide warning indication(s) to signify that an object has entered one or more of the detection zones, passed through a distance threshold for a particular detection zone, and/or entered the immediate vicinity of the mobility device. The feedback module may also provide a danger indication to signify that an object or surface has entered the immediate vicinity of the mobility device. Individual feedback modules may be activated and/or de-activated through one or more of a physical switch, a wireless switch (e.g., using a smart phone application), and/or a voice-activated mechanism. The feedback module may comprise the computing module or be connected to a separate computing module.

A visual feedback module may be a flexible, movable, component (such as a strap) having visual indicators. A movable feedback module can help ensure that notwithstanding the configuration of the mobility device, the visual feedback module may be positioned on the mobility device or user so that the user can view. The visual indicators may grouped in blocks that map or correspond to detection zones of the sensor module(s). Each block may consist of one or more lights that are activated when an obstacle is detected within an adjustable distance threshold ranges (also referred to as a "distance ranges"), of the detection zone. These distance ranges may be mapped such that specific colours or light intensities occur on the visual feedback module. The mappings may be adjustable. For example, an obstacle that is detected within <NUM> of a sensor module for a particular zone might result in the corresponding block appearing red as a danger indication, while an obstacle that is detected between <NUM> and <NUM> of the sensors module for a particular zone might result in the corresponding block appearing yellow as a warning indication. This component might consist of a structural element to provide shade over the lights, keeping them visible despite bright light conditions, such as direct sunlight.

The haptic feedback module may be a movable component that produces vibrations when an obstacle is detected within any a particular distance range. The intensity, frequency, and/or duration of the vibration may be configured so as to be proportional to the proximity of the obstacle. For example, a warning indication might be communicated to the user by having the haptic feedback module provide a weak and short vibration. A danger indication might be communicated by having the haptic feedback module provide a strong and long vibration. An indication in the haptic feedback module is provided if the proximity value is found to lie within a different distance range than before, or if the proximity value lies within the same distance range as before but differs from the previous proximity value(s) by a specified or adjustable amount. This may help reduce user annoyance in the case, for example, that their mobility device is parked beside a stationary obstacle in the immediate vicinity, and their mobility device does not move any closer to obstacle.

The audio feedback module may be a movable component that plays a prerecorded sound when an obstacle is detected within any of the adjustable distance thresholds. The volume and/or frequency of the sound can be proportional to the proximity of the obstacle, and may be adjustable. For example, a warning indication might be communicated in a soft voice, or as a soft beep or low-frequency tone, while a danger indication might be communicated in a loud voice, or a loud beep or high-frequency tone. A sound is provided if the proximity value is found to lie within a different distance range than before, or if the proximity value lies within the same distance range as before but differs from the previous proximity value(s) by a specified or adjustable amount. This may help prevent user annoyance in the case, for example, that their mobility device is parked beside a stationary obstacle in the immediate vicinity, and their mobility device does not move any closer to obstacle.

The visual, audio, and/or haptic feedback modules may be integrated into a single movable, flexible component, or be provided as separate devices or components of the system. In addition, the visual, haptic, and/or audio feedback modules may be embodied in a smart device application on a mobile phone, where the visual feedback is displayed within an application, the haptic feedback is provided through the smart device's vibrating motor, and the audio feedback is provided through the smart device's speaker.

The feedback module(s) may be mounted directly to the mobility device, on the user's person, on or within the sensor module(s), or any combination of the above. The feedback module(s) may be fastened to the mobility device, the user's person, or within the sensor module(s) in a number of ways including, fabric fasteners/straps, adhesives, rigid couplers, or some combination thereof. The feedback module may include a system of spacers or supports that allow the precise position and attitude of each module to be adjusted during and after mounting.

<FIG> show various views a feedback module <NUM> in accordance with an embodiment of the present disclosure. The feedback modules <NUM> is a visual feedback module similar the feedback module <NUM> shown in <FIG>. The feedback module <NUM> receives data from the sensor module, analyzes the data, and provides aggregated information to a user. The aggregated information may reflect the proximity and/or locations of objects and/or surfaces of objects within the vicinity of the mobility device being monitored by the sensor module(s).

Referring to <FIG>, the feedback module <NUM> comprises a body <NUM>. The top surface <NUM> of the body <NUM> provides a visual user interface for displaying aggregated information to the user. The top surface <NUM> may comprise a cover defining cutouts or windows so that lights within the body <NUM> or visible to a user.

As shown in <FIG>, the top surface may be a transparent sheet of plastic or glass. An overlay <NUM> defining cut-outs or windows may be placed on the transparent sheet so that only certain lights below the transparent sheet are visible to a user. The overlay <NUM> may be a flexible piece of plastic with an adhesive backing such as a sticker. The sticker may have perforated areas to allow a user to remove portions of the sticker before installation to provide the cutouts or windows. This could allow a user to customize what lights of the feedback module <NUM> they wish to see. This customization could be performed by the user at the time of installation on the mobility device. The feedback module <NUM> also comprises a vibration control <NUM> which allows a user to set the intensity of vibrations in a haptic module. The vibration control <NUM> comprises a knob <NUM> attached to a potentiometer <NUM>. This allows the user to fine-tune the vibration intensity. The knob may have a stop thereon which limits the amount by which the potentiometer may be rotated. A stop which limits the rotation of the potentiometer to less than the maximum rotation possible may be desirable so a user cannot inadvertently set the vibrations to the maximum possible intensity. This might be particularly useful for users who may, for example, have day-to-day variations in their sensitivity or tolerance of vibration stimuli. The feedback module <NUM> comprises a port <NUM>. The port <NUM> is so the feedback module <NUM> can be electrically connected to the sensor module and/or a haptic module or a power supply. The feedback module <NUM> also comprises a bracket <NUM> so it can be fastened to a mobility device. The bracket can accommodate a bolt or a similar rod-type structure to allow the feedback module <NUM> to pivot about the axis of the bracket <NUM>. A user may wish to change the angle of the feedback module <NUM> to, for example, have a better view of the top of the feedback module <NUM> or limit the interference from overhead light such as from the sun.

<FIG> shows a top view of another embodiment of a sensor module <NUM> in accordance with the present disclosure. <FIG> is a close-up view of the region around the sensor module <NUM> of <FIG>. The sensor module <NUM> is similar to the sensor module <NUM> shown in <FIG>. The sensor module <NUM> comprises proximity sensors <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. The proximity sensors may be ultrasonic sensors. Each of the proximity sensors <NUM>, <NUM>, <NUM>, <NUM>, <NUM> is configured to detect the proximity of a surface to the sensor within a corresponding area of coverage <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>, respectively. If the proximity sensor is an ultrasonic sensor, it may be configured to detect the surface which is closest to the face of the sensor. <FIG> shows the areas of coverage <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> as two-dimensional planes for ease of visualization, but it will be appreciated that the areas within which the sensors can detect the proximity of a surface are actually three-dimensional volumes having a conic shape. The surface which the sensors detect may belong to an object such as a box <NUM> as shown in <FIG>.

Referring to <FIG>, centre sensors <NUM>, <NUM>, and <NUM> are configured so that sensors <NUM> and <NUM> are each angled inwards by <NUM> degrees relative to middle sensor <NUM>. This results in a number of positive attributes. First, all three sensor cones <NUM>, <NUM>, and <NUM> converge and overlap in the area close to the front of the sensor module <NUM>. This results in redundant sensor coverage for the area immediately adjacent the front of the sensor module <NUM>. It is important to have an accurate reading in this area. An inaccurate reading could result in a collision. Second, all three sensor cones are at significantly different angles to one-another in this area of overlap. Having different sensor cone angles covering the same area allows a large number of surface angles to be detected by the three sensors, collectively, within that area. As previously noted, a single ultrasonic sensor (and an inexpensive ultrasonic sensor in particular) has increasing difficulty detecting a surface the more that surface tends towards an angle perpendicular to the face of the sensor. Third, the three sensor cones extend well past the area of convergence (as shown in <FIG>) to cover the area at a distance from the sensor module <NUM>. Fourth, sensor cones <NUM> and <NUM> also extend into (so as to overlap with) side sensor cones <NUM> and <NUM>, respectively, providing additional redundancy (at two different angles) for those areas. Fifth, the total area covered by the combination of all five sensors <NUM>, <NUM>, <NUM>, <NUM>, <NUM> at their particular angles results in an aggregate view angle of <NUM> degrees with limited blind spots. Using multiple inexpensive ultrasonic sensors in the foregoing configuration may provide the information required by a user, but at a cost that is significantly less than what it would be for fewer higher-quality sensors (such as Lidar sensors).

By way of example, no surface of box <NUM> is detected by sensor <NUM> because the angles of the two closest surfaces of the box <NUM> are <NUM> degrees to the face of sensor <NUM>. The two surfaces, however, are each detected by one of sensors <NUM> and <NUM> since the each of the surfaces is parallel to one of those two sensors. In an embodiment, a processor in communication with the sensors <NUM>, <NUM>, <NUM> receives the readings from the sensors of the distances to the box surfaces detected. According to the algorithm, the sensor cones of sensors <NUM>, <NUM>, <NUM> collectively cover a middle detection zone. The middle detection zone would include all of the area covered by cones <NUM>, <NUM>, and <NUM>. The middle detection zone has a corresponding indicator for the user feedback module(s). The processor aggregates the distance readings of the sensors <NUM>, <NUM>, <NUM> covering the middle detection zone. Aggregation may comprise selecting the reading amongst the three sensors with the smallest distance, which is the reading from sensor <NUM> since it is closest to a surface of the box <NUM>. This smallest distance reading is used to represent the distance of the surface of the object in the detection zone relative to a reference location on the sensor module. The sensor module <NUM> has multiple groups of one or more sensors. Sensor <NUM> belongs to a first group. Sensors <NUM>, <NUM>, and <NUM> belong to a second group. Sensor <NUM> belongs to a third group. The processor is configured to correlate the first group sensor readings with the left detection zone, the second group sensor readings with the middle detection zone, and the third group sensor readings with the right detection zone. Note the overlap in are of coverage between the detection zones. The processor controls a user feedback module according to the unitary value selected for each detection zone at a particular time. The user feedback module may comprise three lights, each of the lights corresponding to one of the left, right, and middle detection zones. The middle light corresponds to the middle detection zone. The processor may illuminate and set the colour of a particular light according to the unitary value for the corresponding detection zone. The colour/intensity of the light may be in accordance with a distance threshold range. The user feedback module may use any visual display to notify a user of the presence and/or proximity of a surface within a detection zone. For example, the user feedback module may comprise a screen. The screen may show representations of the detection zones. The screen may also show representations of the mobility device and surfaces detected within the detection zones. The algorithm may smooth the selected reading for a detection zone so that small changes in distance, particularly going from a closer distance range (e.g. danger) to a longer distance range (e.g. warning) is ignored if that longer distance range has not been observed for a threshold period of time. Changes in the other direction (longer distance range to shorter distance range) may always be reported to the user to help ensure a user has notification if a surface is indeed getting closer.

The system can provide users of mobility devices with information regarding the presence and locations of obstacles in their vicinity. Collisions with these obstacles may be difficult to avoid, however, due to a user's difficulty controlling the mobility device, or the user's inability to see or be otherwise aware of obstacles. For this reason, the system/device may also comprise an intervention module which can intervene in the event of an impending collision by a mobility device by controlling the speed, acceleration, or other properties of the mobility device.

Claim 1:
A system, comprising:
two or more sensors (<NUM>, 304a-e, 504a-e, 404b-c, 404e, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) each configured to detect the proximity of an object to the sensor (<NUM>, 304a-e, 504a-e, 404b-c, 404e, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) within an area of coverage (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>);
a computing module configured to control a sensor module (<NUM>) and analyzing the data received from the sensor module (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>,<NUM>); and
a user feedback module (<NUM>, <NUM>, <NUM>) for providing information to a user of a mobility device regarding the proximity of the mobility device to an object based on the sensor module (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) data analyzed by the computing module,
and characterised by the two or more sensors (<NUM>, 304a-e, 504a-e, 404b-c, 404e, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) being comprised by the sensor module (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>), wherein the sensor module retains the two or more sensors such that the face of each of the two or more sensors is at a different angle to the face(s) of the other sensor(s), wherein two sensors (304a, 304c, <NUM>, <NUM>) of the two or more sensors are each positioned at an inward-facing angle relative to a back plane (<NUM>) of the sensor module to provide redundancy in the sensor readings, wherein the two sensors are positioned to each generate an area of coverage, and wherein the computing module is configured to aggregate the sensor readings from a group of the sensors having overlapping areas of coverage collectively defining a detection zone, the computing module configured to aggregate by selecting the reading with the smallest distance.