WO2011134638A1

WO2011134638A1 - Movement sensitive devices

Info

Publication number: WO2011134638A1
Application number: PCT/EP2011/002080
Authority: WO
Inventors: Roger Antonsen; Jan Dyre Bjerknes
Original assignee: Universitetet I Oslo
Priority date: 2010-04-28
Filing date: 2011-04-26
Publication date: 2011-11-03
Also published as: GB201007116D0

Abstract

An apparatus comprising a plurality of movement sensitive devices, each device comprising an indicator and a movement sensor, wherein the indicator is arranged to provide an audible and/or visual indication based on the movement of the device, and wherein the plurality of devices are arranged to receive information from each other and transmit information to each other. The devices may be juggling balls arranged for interactive illumination in response to movement during juggling.

Description

MOVEMENT SENSITIVE DEVICES

The invention relates to an apparatus comprising a plurality of movement sensitive devices, each device comprising an indicator and a movement sensor.

The device of the invention may be advantageously put to use in the fields of: juggling balls, interactive toys and social games, decorative arts and lightning (e.g. mood lights), physical rehabilitation, arts and science projects.

Juggling balls with LED lighting already exist, but these balls must be pre-programmed in order to change colours in a particular pattern. Various toys and games incorporating light and sound also exist. Mood lights also already exist, typically lighting different colours in sequence or according to the user's selection.

The invention provides an apparatus comprising plurality of movement sensitive devices, each device comprising an indicator and a movement sensor, wherein the indicator is arranged to provide an audible and/or visual indication based on the movement of the device, and wherein the plurality of devices are arranged to receive information from each other and transmit information to each other.

Since the devices can receive and transmit information from one another then they can co-ordinate their indications without the need for control by an external control device. In preferred embodiments the devices may transmit information relating to the movements detected by the movement sensors and this advantageously enables them to identify and utilise inter-relationships between the movements of the devices. For example, a pattern of movement of the devices may be detected and this can be used to produce a corresponding pattern or sequence of indications by one or more of the devices.

The sensors preferably comprise an accelerometer, preferably a three axis

accelerometer. This enables movements of the device to be detected without requiring a particular orientation of the device. There is no requirement for any axis of a three axis accelerometer to be aligned with a movement direction in order for the movement to be detected.

The indicators may provide a visual indication in the form of a light. Audible indications may also be used as an alternative or in addition to visual indications. The indicators are preferably arranged to provide different coloured lights for different movement. The indicators may also provide different colours of light based on different sequences of movements of the multiple devices.

Preferably the devices each comprise a wireless communicator for wireless

communication of the information. For example, a radio frequency transmitter and receiver may be included in the device. The devices are advantageously physically separated from one another and ideally should be able to exchange information over relatively large distances (for example, several metres or more). The use of a wireless communicator enables the devices to exchange information when spaced apart. In one preferred embodiment the wireless communicator has a range of up to 50 metres. This provides a large degree of flexibility in the way that the devices can be used and in the way that they can interact together.

Each device may be arranged to detect throwing and landing patterns of the device, for example throwing and landing events when the device is used for juggling or a similar movement. This enables the devices to react to throwing and landing patterns. The devices may wirelessly transmit indications of throwing or landing events to one another.

In preferred embodiments each device comprises a controller for controlling the indicator of the device in response to outputs of the movement sensor. The controller may be a microcontroller. Preferably, the controller is also for processing the information sent between the devices and it may control the indicator in response to information sent between devices. Thus, the controller may be for processing indications of throwing and landing events. It may control the indicator in response to such events, for example so that an indication occurs in response to a detected throwing or landing event or in accordance with a detected or predicted throwing and landing pattern.

In a preferred embodiment the apparatus may be used for juggling. With this application, detected throwing and landing events may be used to determine a juggling pattern. The juggling pattern may be based on conventional juggling pattern notation. For example, the Siteswap notation. Preferably, the juggling pattern is used to predict a Siteswap value for the next throw. The devices may be arranged to operate the indicator based on the predicted juggling pattern and/or Siteswap value.

In one particularly preferred arrangement, the devices are arranged to predict the Siteswap value for the next throw by: in response to receiving an indication of a landing event from another device, incrementing an internal counter of the device by one; setting the internal counter to one each time the device itself lands; determining the number of throws of other devices since the device itself was thrown as the value of the counter just before the device lands. The device may transmit the Siteswap value of the throw to the other devices of the apparatus.

The devices may be balls, preferably balls comprising a translucent or at least partially transparent shell containing the other parts of the device. The device may be sized to fit within the hand, for example sized to fit comfortably within an average adult hand. The device may thus be a ball with a diameter between 5-10cm. Such sizes can be used for juggling and similar activities. Larger sized and/or non spherical devices might be preferred for other uses, for example for co-ordination exercises or the like. The preferred embodiment of the invention is a device with sensors, a microcontroller, wireless communication and multicoloured LEDs, such that one, or several devices together, can be used for a large number of applications. The devices communicate with the user by lighting up in different colours and strength based on the sensor inputs and relation to other devices. There are numerous possible applications, for instance, but not limited to, intelligent juggling balls, decorative arts and lighting, games and toys, and rehabilitation tools.

As noted above, juggling balls with LED lighting exist, but in contrast to the device described herein, the colours do not change according to how they are thrown. Similarly, mood lights exist but they are not reactive or interactive, and are not wirelessly controlled.

In the preferred embodiment described below, the sensor currently used is a simple three-axis accelerometer, and a controller such as a microprocessor reads and processes the signals from said sensor. The processed information is shared between the devices and between the controllers of the devices by means of a RF transceiver. All calculations and measurements are done without the help of an external computer. The microprocessor is programmed with algorithms for detecting juggling patterns, which enables the devices to predict the next throws and display colours accordingly.

Preferred embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings, in which:

Figure 1 is a schematic diagram of an embodiment of a movement sensitive device; and Figure 2 shows a preferred embodiment taking the form of a ball, which is shown with two halves open exposing the internal parts.

All the hardware used in the preferred embodiment is readily available in the market. At the core of the device is a microcontroller connected to an accelerometer, radio transceiver and driver FETs for controlling LED lights. As the microcontroller cannot supply the current for the LEDs itself, three N-channel FETs, one for each colour, are used as switches. By mixing colours from the three basic LED colours, any colour can be obtained.

A schematic for the preferred embodiment is shown in Figure 1. In the preferred embodiment, the microcontroller samples all three axes on the accelerometer at 125 Hz, and calculates the force acting on the ball at each time step. By measuring when the force in all three axes falls below a predefined threshold, free fall can be detected. Other acceleration forces can also be detected such as impacts occurring when a ball lands and acceleration as a ball moved in the hand in preparation for throwing. Measurements of the relative accelerometer readings on the three axes can be used to detect movements that change the orientation of the device.

In addition to free fall detection and movement detection, the microcontroller also transmits and receives information to and from other similar balls. The preferred embodiment uses a low bandwidth (19200 bps) two-way radio, with range up to 50 meters. With a range of 50 metres several new games or activities can be programmed into the balls, and each player in the game can use one or several balls.

Intelligent devices with visual amplification combine a set of algorithms with the built-in accelerometer to calculate whether they are resting or flying in the air. By broadcasting this information to other similar devices over radio, the devices can calculate how long they fly in relation to other devices and in which order they land. Due to the re-programmable nature of the devices they can be used for many different purposes based on their programming. A number of examples are set out below, including: intelligent juggling balls, new games for children, mood lights, and rehabilitation.

An important part of the preferred embodiment is the novel use of existing hardware. Using accelerometer for free fall detection is already quite common, but sharing this information between several objects to detect throwing and landing patterns is new. Particularly in the juggling case described in some detail below, it will be apparent that determining the order in which devices are thrown and caught allows us to determine the juggling pattern. The control algorithms identify the current juggling pattern, and can thus predict how a ball will be thrown.

The devices, preferably balls, are made out of the following parts:

• An outer semi-soft and translucent Silicone shell 2.

• A printed circuit board 4 with:

· A microcontroller.

• A three-axis accelerometer.

• A two way radio (19200 bps).

• Three MOSFET used as switches.

• Two tricolour LEDs.

· A Voltage regulator.

• Misc. resistors and capacitors.

Figure 2 shows an example embodiment in the form of a spherical ball. The silicone shell 2 is split in two halves so that the internal parts can be seen, including the printed circuit board 4 and associated parts as listed above.

The silicone shell serves several purposes. First, it allows for an easy grip on the ball, i.e. a non-slippery surface. The shell also protects the electronics on the inside against dirt and humidity. Finally, the shell allows the light from the light emitting diodes to shine through, giving the device the ability to display different colours.

At the core of this project is the microcontroller. The depicted preferred embodiment uses a microcontroller with the designation dsPIC30f4012 produced by Microchip Technology Inc. of Arizona USA. Any microcontroller with similar capabilities and sufficient peripherals could be used.

The three-axis accelerometer has two different roles. It is used for free fall detection in applications where this is necessary (e.g. juggling) and it is used to determine how the device is rotated when resting in the applications where this is useful (e.g. in mood lighting). The accelerometer has three analogue outputs, and a range of up to +- 4 G. The analogue outputs are sampled by the microcontroller at 125 Hz, and the forces acting on the ball at each time step is calculated. This gives us a clear indication of the device's positional status.

The radio unit provides full data communication between all the devices. Based on application, different type of information will be shared between the devices.

The primary user interface of the devices are coloured light. Each device contains a few multicoloured LEDs allowing the devices to light up in almost any colour.

The devices described herein were initially conceived of as an intelligent juggling prop. However, several other uses are easily implemented due to the reprogrammable nature of the devices. A few example applications and further detail of the juggling implementation are set out below.

Rehabilitation: Since the devices can precisely measure the force acting on them, and have the ability to emit light in different colours, they can give very direct feedback on how they are moved. For someone with a movement challenge the invention will be an excellent training partner. Flight time and hard versus soft catches can be colour coded. It is also possible to measure mimicking, i.e., an instructor demonstrates a movement sequence, and the client / student will copy. The devices will determine similarity between the instructor's movement sequence and the repeated sequence.

Mood light: A simple application is mood lights. If the devices are distributed in the room, any device that is being moved can use the accelerometer to determine its orientation in space. The orientation can be colour coded, and broadcasted to the other devices and they will change their colour accordingly.

Juggling: The Siteswap notation is a method for describing juggling patterns. The notation captures one of the most essential properties of a pattern: the order of throwing of the objects, which may for example be balls. All the other aspects of juggling patterns, like hand positions and body movements, are disregarded. For simplicity, we shall assume that the juggler has two hands, that the hands throw alternately, that only one ball is thrown or held at a time and that the hands throw with an even underlying beat. (The Siteswap notation also extends to juggling patterns without these assumptions, but this is not necessary for our purpose.) A juggling pattern can then be described by assigning a particular number to each throw, a number stating how many beats later the same ball is thrown again.

For instance, if one juggles three balls - a, b and c - in the most common way, the balls are thrown in the following order: a b c a b c a b c .... The Siteswap notation represents this as 333333, because all the balls are thrown again after 3 beats. A slightly different throwing order, a b c c a b b c a a b c c ..., is represented as 441441441 , for the following reasons. The first ball (a) is thrown again after 4 beats (with b c c as intervening throws), the second ball (b) is thrown again after 4 beats (with c c a as intervening throws), and the third ball (c) is thrown again after 1 beat (immediately, with no intervening throws), etc. The precise definition of a Siteswap value is the following: throwing a (Siteswap value of) X means that this same ball will be thrown again X beats later, that is, after X-1 intervening throws. A higher Siteswap value means that the ball needs to be thrown higher.

If a sequence of Siteswap values repeats, it is common to write down the smallest repeating sequence. In the above example, the pattern is simply referred to as 441. For example, in order to juggle the pattern 51 , one hand will only be throwing 5's and the other hand only 1 's. (This characteristic pattern is called a 3-ball shower. The balls are thrown in the following order: a a b b c c a a b b c c ....) The definition of a Siteswap number is general enough to capture juggling patterns with any number of balls. For example, the pattern 91 is a 5-ball shower similar to the pattern 51 with 3 balls. (A mathematical fact is that the average of the numbers in a pattern always equals the number of balls.) It follows from the assumptions that if a ball is thrown with even value, it lands in the same hand, and that if a ball is thrown with an odd value, it lands in the opposite hand. Therefore, in the juggling pattern 4, two balls are juggled in the left hand and two balls are juggled in the right hand.

There is a special case in the Siteswap notation for an empty hand. If a hand is empty and does not throw, this is represented with the number 0. For example, the 2-ball pattern 330 is simply the pattern 3, where one of the balls is gone. Currently, we have not implemented a way of detecting 0's, but this may be achieved by keeping track of the underlying beat and filling in the gaps with 0's in the correct way.

The Siteswap value of 2 also requires special attention because it is common among jugglers to not throw 2's at all. A throw of value 2 must be caught and thrown with the same hand again (because it is an even number), so it is more convenient for a juggler to let the ball stay in the hand until the next throw of value other than a 2, rather than actually throwing it. For example, the pattern 42 is commonly juggled with one hand holding a ball and the other hand juggling two balls. If the 2 is thrown, it is called an active 2, and if the 2 is held, it is called a passive 2. The detection of active 2's is not hard at all, while the detection of passive 2's can require special attention.

The balls of the preferred embodiment are designed to detect juggling patterns and use this information to predict the Siteswap value of the next throw. Furthermore, the Siteswap value may be used for predicting exactly when the next ball peaks, etc., but this presupposes that the balls are actually juggled with an even beat. The method for calculating the sequence of thrown Siteswap value, and thereby making the detection of juggling patterns possible, is as follows.

Each ball has an internal counter that is incremented by one each time another ball lands and that is set to one each time itself lands. When a ball lands, its counter is therefore equal to the number of throws since itself was thrown. By definition, this number is the

Siteswap value of the throw, and this number is broadcasted to the other balls immediately when it lands. Since all the Siteswap values are broadcasted in this way, it is possible for each ball to rearrange the values to obtain the original throwing sequence and hence to predict the value of the next throw. Each time a ball lands, the value of the counter is broadcasted and thereafter set to one. Furthermore, whenever a ball receives a Siteswap value (from a ball that has landed), its internal counter is incremented by one. This has the effect that when a ball lands, its counter equals its Siteswap value.

For example, when a ball lands, its counter is set to one, and if no other ball lands before this ball lands again, its counter equals its Siteswap value, namely 1. If two balls lands before this ball lands again, its counter equals 3, etc.

Notice that a simple sequence of broadcasted Siteswap values is not a proper Siteswap sequence representing a juggling pattern. This is because the values are broadcasted in the order in which they landed, not in the order in which they were thrown. It is, however, easy to rearrange the numbers into the proper sequence. For example, consider the juggling pattern 4413. If this is juggled, the sequence of broadcasted signals is 443144314431 .... The repeating pattern, 4431 , is not a valid juggling pattern (because 4 immediately followed by 3 is impossible without capturing two balls at the same time). However, reconstructing the actual sequence of throws is not hard.

Scientific tools: With hundreds or even thousands of balls, large-scale scientific experiments can be conducted. By creating local rules, global patterns will emerge based on how each ball is being treated. This can be used to conduct social experiments, demonstrate entropy in physics, wave propagation, social inclusion and exclusion, and so on. Until now, all large-scale experiments of this type have involved computer simulations on a screen. The intelligent balls make it possible to do these experiments outside a computer. For science communication this is a very important feature as it allows many people to participate, instead of being passive spectators.

In a similar fashion, a medium number of balls (typically 20-50) can be used in school- classes to conduct smaller experiments equal to those described above. Thus, smart balls can be a very useful tool for both natural and social science education, and potentially have a strong impact, due to the fact that each member of the class now participates in each experiment. If one member in a class decides to deliberately sabotage an experiment by not treating its ball as necessary for the experiment to work, this can be turned into an advantage.

Games: on a less serious note, the intelligent balls can be used for new types of games for children and adolescents. Due to the wireless nature of the balls, they can be programmed for entirely new games of cooperation and team play. For example, by having a ball light up in a specific colour, a certain action is required by its holder. As two or more balls light up at the same time, increasingly complex and simultaneous actions must be performed by the people who hold the illuminated balls. The balls can detect if the appropriate action is carried out and indicate if the ball holder has completed the action or failed to do so.

Certain preferred embodiments are described in the following numbered clauses:

1. A movement sensitive device comprising an indicator device and a movement sensor, wherein the indicator device is arranged to provide an audible and/or visual indication based on the movement of the device.

2. A device as described in clause 1 , wherein the sensor comprises an

accelerometer, preferably a three axis accelerometer.

3. A device as described in clause 1 or clause 2, wherein the indicator device provide a visual indication in the form of, a light.

4. A device as described in clause 3, wherein the indicator device is arranged to provide different coloured lights for different movement.

5. A device as described in any preceding clause, comprising a wireless communicator for wireless communication with other similar devices.

6. A device as described in any preceding clause, comprising a controller for controlling the indicator device in response to outputs of the movement sensor.

7. A device as described in any preceding clause, wherein the device is a ball, preferably a ball comprising a translucent or at least partially transparent shell containing the other parts of the device.

8. A device as described in any preceding clause, the device being arranged to detect throwing and landing patterns of the device, for example throwing and landing events when the device is used for juggling.

9. A device as described in clause 8, wherein the device wirelessly transmits an indication of a throwing or landing event. .

10. A device as described in clause 8 or clause 9, wherein detected throwing and landing events are used to determine a juggling pattern.

11. A device as described in clause 10, wherein the juggling pattern is used to predict a Siteswap value for the next throw.

12. A device as described in clause 11 , wherein the device is arranged to predict the Siteswap value for the next throw by: in response to receiving an indication of a landing event from another device, incrementing an internal counter of the device by one; setting the internal counter to one each time the device itself lands; determining the number of throws of other devices since the device itself was thrown as the value of the counter just before the device lands.

13. A device as described in clause 11 or 12 wherein the device transmits the Siteswap value of the throw.

14. Multiple devices as described in any preceding clause, arranged to receive and transmit from each other.

Claims

1. An apparatus comprising a plurality of movement sensitive devices, each device comprising an indicator and a movement sensor, wherein the indicator is arranged to provide an audible and/or visual indication based on the movement of the device, and wherein the plurality of devices are arranged to receive information from each other and transmit information to each other.

2. An apparatus as claimed in claim 1 , wherein the sensors comprise an accelerometer, preferably a three axis accelerometer.

3. An apparatus as claimed in claim 1 or claim 2, wherein the indicators provide a visual indication in the form of a light. 4. An apparatus as claimed in claim 3, wherein the indicators are arranged to provide different coloured lights for different movement.

5. An apparatus as claimed in any preceding claim, comprising a wireless communicator for wireless communication of the information.

6. An apparatus as claimed in any preceding claim, wherein each device comprises a controller for controlling the indicator of the device in response to outputs of the movement sensor. 7. An apparatus as claimed in any preceding claim, wherein the devices are balls, preferably balls comprising a translucent or at least partially transparent shell containing the other parts of the device.

8. An apparatus as claimed in any preceding claim, each device being arranged to detect throwing and landing patterns of the device, for example throwing and landing events when the device is used for juggling or a similar movement.

9. An apparatus as claimed in claim 8, wherein the devices wirelessly transmit indications of throwing or landing events to one another. 0. An apparatus as claimed in claim 8 or 9, wherein detected throwing and landing events are used to determine a juggling pattern.

1 1. An apparatus as claimed in claim 10, wherein the juggling pattern is used to predict a Siteswap value for the next throw.

12. An apparatus as claimed in claim 11, wherein the devices are arranged to predict the Siteswap value for the next throw by: in response to receiving an indication of a landing event from another device, incrementing an internal counter of the device by one; setting the internal counter to one each time the device itself lands; determining the number of throws of other devices since the device itself was thrown as the value of the counter just before the device lands.

13. An apparatus as claimed in claim 11 or 12 wherein the device transmits the Siteswap value of the throw.

14. An apparatus substantially as hereinbefore described with reference to the accompanying drawings.