Wireless Hierarchical Heterogeneous Pico-Net for Ski Control Systems

• US 20150249482A1
• Filed: 03/14/2015
• Published: 09/03/2015
• Est. Priority Date: 10/28/2013
• Status: Active Grant

• Current Assignee: Stanislaw Czaja
• Original Assignee: Stanislaw Czaja
• Inventors: Czaja, Stanislaw
• Granted Patent: US 9,673,864 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A43B 1/0054 provided with magnets, magnetic parts or magnetic substances
• CPC Class Codes: A43B 3/34 with electrical or electronic arrangements
• CPC Class Codes: A43B 5/0415 Accessories A43B5/0403, A43B5/0413, A43B5/0494 take precedence
• CPC Class Codes: A63C 2203/18 Measuring a physical parameter, e.g. speed, distance
• CPC Class Codes: A63C 2203/22 Radio waves emitting or receiving, e.g. remote control, RFID
• CPC Class Codes: A63C 5/06 with special devices thereon, e.g. steering devices
• CPC Class Codes: A63C 9/00 Ski bindings
• CPC Class Codes: G16H 20/30 relating to physical therapies or activities, e.g. physiotherapy, acupressure or exercising
• CPC Class Codes: G16H 40/63 for local operation
• CPC Class Codes: G16H 40/67 for remote operation
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04L 47/6225 Fixed service order, e.g. Round Robin
• CPC Class Codes: H04W 4/38 for collecting sensor information
• CPC Class Codes: H04W 4/80 Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication
• CPC Class Codes: H04W 84/20 Master-slave selection or change arrangements
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A wireless hierarchical heterogonous pico-net providing communication between smart-phone based analysis and control application and multiplicity of sensors and actuators embedded in the ski equipment is described. The topology of this pico-net comprises two layers of hierarch, where the first layer is configured as a Bluetooth wireless network using a Round-Robin scheduling method and consisting of a single master and up-to seven slaves, and the second layer of the hierarchy is configured as a sub-nets consisting of multiplicity of sensors and actuators and communicating internally using ANT personal area network (PAN) wireless interface, or via a digital wire interface. Such network topology provides deterministic latency of a hierarchy a single-hop Bluetooth network, irrespective of the numbers of sensors and actuators embedded within each sub-net of the second layer of hierarchy. The network latency is upper-bounded by the number of slaves in the first layer of hierarch, Furthermore, the Round-Robin scheduling method is supplemented with the gating-off the slave RF transmission when the slave has no data to send, or when the difference between current sensor samples and the previous sensor sample is smaller then predefined threshold. Such discontinued transmission lowers slave power consumption system interference.

Claims

1. A wireless hierarchical heterogonous network providing communication between a smart-phone based analysis and control application and a multiplicity of sensors and actuators embedded in the ski equipment comprising:

a first layer of network hierarchy composed of a smart-phone based Bluetooth master transceiver and up to seven Bluetooth slave transceivers embedded in the ski equipment;

a second layer of the network hierarch composed of up to seven network sub-nets, each comprising multiplicity of Microelectromechanical Systems (MEMS), sensors and actuators;

and wherein the master of the first layer of the network hierarch using a Round-Robin scheduling scheme sends to each slave of the first layer of the network hierarch a control pocket comprising;

an access code of the sub-net;

a header of the packet consisting packet number; and

the control packet payload comprising multiplicity of control records dedicated for each individual device within the sub-net; and

wherein upon reception of said control packet, the slave responds with a packet data containing samples obtained from sensors located within the sub-net.

2. The system of claim 1, wherein the first layer of network hierarchy is configured as a single master pico-net, in which each of the pico-net slave provides a single-hop bridge to all devices located within the sub-net.

3. The system of claim 1, wherein the second layer of network hierarch is configured as a sub-net comprising multiplicity of sensors and actuators, wherein the latency of said sub-net is smaller then the schedule period of the network first layer.

4. The system of claim 3, wherein said sub-net is configured in form of a sub-system communicating using digital wire interfaces and comprising of:

a Bluetooth slave;

a micro-controller (MCU); and

a multiplicity of sensors and actuators.

5. The system of claim 3, wherein said sub-net is configured in form of a sub-system communicating using an ANT Personal Area Network (PAN) wireless interface, and comprising of:

a Bluetooth slave;

a control processor (MCU); and

a multiplicity of sensors and actuators.

6. The system of claim 5, wherein the Bluetooth slave of said sub-net performs master function of the ANT network.

7. The system of claim 1, wherein the control packet received by the sub-net Bluetooth slave is delivered to the control processor (MCU), and wherein the MCU disassembles it'"'"'s payload into individual control records, then:

requests new data samples from each sensors identified in the accelerometer control record;

for each sensor compares the current sample with the previous sample, and if the difference between said consecutive samples is smaller then the predefined, replaces the new sample with the ‘

zero’

value, otherwise appends the current value to the sensor data packet;

sends the sensor data packet containing samples from all sensors identified in the accelerometer control record the Bluetooth slave for transmission to the master;

for each actuator control record located within the control packet payload;

extracts the actuator identity and the actuator control word;

applies the content of the actuator control word as an address to the look-up table (LUT); and

applies the content obtained from the LUT to the actuator as the as a control signal.

8. The system of claim 7, wherein the actuator control record comprises:

an actuator identifier; and

a control word containing address to the Look-up Table (LUT), stored in the sub-system MCU memory in form of M*N array, containing the amplitude and frequency response the actuator control signal.

9. The system of claim 8, wherein the address location of the LUT included in the actuator control word is obtained by calculating the Mean Squared Error of the piece-wise fit between the optimal control signal and the control signal impulse response stored in the LUT.

10. The system of claim 8, wherein the actuator control signal stored in the LUT is applied directly to the pulse-width-modulation (PDM), digital-to-analog (DAC), converter, and wherein the density of ‘

1s’

included in control signal defines the actuator time response, while the total number of ‘

1s’

the amplitude of the actuator control signal.

11. The system of claim 8, wherein the N parameter of the LUT depends on the network hierarchy first layer schedule period and the control signal desired time and amplitude resolution and it'"'"'s maximum amplitude.

12. A computer accessible non-transitory memory medium for storing program instructions configured to control a hierarchical network providing communication between a smart-phone based analysis and control application and a multiplicity of sensors and actuators configured as a sub-nets and embedded in the ski equipment, wherein the program instructions executes all of the following:

in each time slot dedicated to the Bluetooth master transmission, using a Round-Robin scheduling method, the master sends to the selected sub-nets a control packet comprising control commands to all devices located within the selected sub-net;

in each time slot dedicated to the Bluetooth master reception, the Bluetooth master receives sensor data packet from the selected sub-net, and if said transmission was not received, uses data packet received in the previous schedule time.

13. The method of claim 12, wherein the control packet payload comprises of:

an accelerometer control record identifying individual sensors located within the sub-net;

a multiplicity of actuator control records; and

wherein said control packet record size is adjusted to the appropriate Bluetooth packet size by appending “

0s”

before said packet is encoded by using forward error correction (FEC) code.

14. The method of claim 13, wherein the accelerometer control record comprises identifiers of each accelerometer located within the selected sub-net, and wherein said identification represents a request for data from the selected sensor.

15. The method of claim 13, wherein the actuator control record comprises of an actuator identifier and an actuator control word;

wherein the actuator control word contains an address to the look-up table (LUT), containing an actuator control signal; and

wherein the address to the LUT is obtained by calculating a Mean Squared Error of piece-wise fit between the optimal control signal and the impulse response stored in the LUT.

16. A computer accessible non-transitory memory medium for storing program instruction configured to control the sub-net of the network providing communication between a smart-phone based analysis and control application and a multiplicity of sensors and actuators configured as a sub-nets and embedded in the ski equipment, wherein the program instructions execute all of the following:

for each control packet received from the Bluetooth master, the sub-net control processor performs the following;

for each sensors identified in the accelerometer record retrieves sensor samples, compares the current sample with the previous sample, and if the difference between said consecutive samples is smaller then the predefined threshold, replaces the new sample with the ‘

zero’

value;

assembles samples from all sensors into a sensor data packet, and if said data packet contains values other then ‘

zeros’

sends said packet to the Bluetooth slave for transmission to the master, otherwise slave transmission is disabled;

for each actuator identified in the control packet retrieve the actuator control word, and applies said control word as an address to the look-up table (LUT), then uses the value stored in this location as a control signal for the selected actuator.

17. The method of claim 16, wherein the communication between all devices located within the sub-net is conducted using a digital wire interface.

18. The method of claim 16, wherein the communication between all devices located within the to the sub-net is conducted using an ANT personal network wireless (PAN) radio interface.

19. The method of claim 16, wherein the actuator control signal stored in the sub-net control processor look-up table (LUT) is applied directly to the pulse-width-modulation (PDM) digital-to-analog converter (DAC), as a control voltage of the selected actuator.