WO2019056947A1

WO2019056947A1 - Method and system for mobile robot task scheduling

Info

Publication number: WO2019056947A1
Application number: PCT/CN2018/104231
Authority: WO
Inventors: 倪江荣; 白静; 李宇翔; 黄珏珅; 陈士凯
Original assignee: 上海思岚科技有限公司
Priority date: 2017-09-19
Filing date: 2018-09-05
Publication date: 2019-03-28
Also published as: CN107678842A

Abstract

A method and a system for mobile robot task scheduling. The method comprises: acquiring information of a scheduled task set by a user operation (S11); updating, in a database, the scheduled task set by the user on the basis of the scheduled task information (S12); synchronizing the scheduled task set by the user in the database according to an acquired request for accessing the scheduled task, and matching the scheduled task set by the user in the database with a current scheduled task to trigger the scheduled task (S13); executing a service corresponding to the scheduled task according to scheduling and decision information of the scheduled task as well as information of a service type determined (S14); and if a current service is complete or a service duration is reached, terminating the currently executed service, and updating the status of the mobile robot (S15). The invention achieves scheduled mobile robot service activation and termination and assists mobile robots in achieving extended automated on-duty states without manual intervention.

Description

Method and system for timing task of mobile robot

Technical field

The present application relates to the field of computers, and in particular, to a method and system for a timed task of a mobile robot.

Background technique

With the rapid development of computer technology, microelectronics technology, network technology, etc., robot technology has also developed rapidly. In addition to the continuous improvement of the level of industrial robots, various advanced robot systems for the service industry have also made great progress. Mobile service robots are becoming more and more popular, such as sweepers, shopping guides, ATMs, and so on. At present, such mobile robots mainly rely on manual manual to open and end services, and the demand for long-term duty and automation services of the robot has become an urgent problem to be solved.

Summary of the invention

An object of the present application is to provide a method and system for a timed task of a mobile robot, which solves the problem of requiring artificially long-term duty of the robot in the prior art.

According to an aspect of the present application, a method for a timed task of a mobile robot is provided, the method comprising:

Obtaining time-critical task information set by the user, where the operation includes at least one of the following: adding, deleting, and modifying;

Updating a timed task of the user in the database based on the set timed task information;

And synchronizing the timed task of the user in the database based on the obtained request for accessing the scheduled task, and matching the timed task of the user in the database with the current timed task to trigger the timed task;

Performing, according to the scheduling and decision information of the timed task and the determined service type information, a service corresponding to the timed task;

If the current service is completed or the service duration arrives, the currently executed service is terminated and the mobile robot status is updated.

Further, in the foregoing method, after matching the timed task of the user in the database with the current timed task, the method includes:

The scheduling task is scheduled and determined based on the matching result of the user's timed task in the database and the current timed task, and is processed when the multi-task is superimposed, and the signal for starting or ending the service is pushed.

Further, in the above method, the method includes:

The environment map and the location information of the mobile robot are determined according to the fusion information in the service process corresponding to the execution of the timing task, and the mobile robot movement path is planned according to the environment map and the location information of the mobile robot.

Further, in the above method, the method includes:

Controlling the motion of the mobile robot based on the environment map, the position information of the mobile robot, and the information of the mobile robot movement path.

Further, in the above method, the method further includes:

Determining a corresponding task decision according to the fusion information in the service process corresponding to the execution of the timed task and the specific situation in the service process;

Controlling the motion of the mobile robot based on the corresponding task decision.

Further, while performing the service corresponding to the timed task, the method includes:

Obtaining a push signal of the periodic operation of the mobile robot;

A decision is generated based on the scheduled task, time, and current service state to control the opening, closing, and restarting of any of the services.

According to another aspect of the present application, there is also provided a system for a timed task of a mobile robot, the system comprising:

a user interaction module, a task database module, a task triggering module, a task management module, and a service module, wherein

The user interaction module is configured to acquire timed task information set by the user, where the operation includes at least one of the following: adding, deleting, and modifying;

The task database module is configured to receive and save a timed task set by a user, and read by the task triggering module;

The task triggering module is configured to read the timed task from the task database module, and match the read timed task with the current timed task to determine whether to trigger the task;

The task management module is configured to receive a trigger task signal of the task triggering module, determine scheduling and decision information of the timed task, and update the state of the mobile robot after receiving the currently executed service end notification;

The service module is configured to execute a service corresponding to the timing task based on the scheduling and decision information of the timing task and the determined service type information.

Further, the task management module is configured to:

Further, the system includes:

The peripheral module is configured to collect, by using multiple sensors, the fusion information in the service process corresponding to the execution of the timing task.

Further, the system includes:

The positioning drawing module is configured to determine the environment map and the location information of the mobile robot according to the fusion information in the peripheral module.

Further, the system includes:

a robot algorithm module, configured to process the fusion information in the peripheral module based on the service type in the service module, and plan the mobile robot movement path according to the environment map in the positioning drawing module and the location information of the mobile robot, and implement the A service of a corresponding service type of a mobile robot.

Further, the system includes:

And a motion control module, configured to control motion of the mobile robot based on an environment map in the positioning drawing module, location information of the mobile robot, and information of a moving path of the mobile robot in the robot algorithm module.

Further, the robot algorithm module is further configured to:

Corresponding task decisions are determined according to specific conditions in the service process collected in the peripheral module, and the task decisions are sent to the motion control module.

Further, the task management module is configured to:

Obtaining a push signal of the periodic operation of the mobile robot;

Further, the system includes:

The communication module is configured to establish communication between the terminal device, the network device, and the mobile robot to update the mobile robot state after transmitting the scheduled task information and receiving the currently executed service end notification.

According to still another aspect of the present application, there is also provided a computer readable medium having stored thereon computer readable instructions executable by a processor to implement a method for a timed task of a mobile robot.

Compared with the prior art, the present application obtains scheduled task information set by the user's operation, wherein the operation includes at least one of the following: adding, deleting, and modifying; updating the user in the database based on the set timed task information. a timing task; synchronizing a timed task of the user in the database based on the obtained request for accessing the timed task, and matching the timed task of the user in the database with the current timed task to trigger the timed task; based on the timed task The scheduling and decision information and the determined service type information are executed, and the service corresponding to the timed task is executed; if the current service is completed or the service duration is reached, the currently executed service is ended, and the mobile robot state is updated. Therefore, the mobile robot can be started and terminated periodically, and the mobile robot can realize the long-term automatic attendance of the unmanned intervention; the user can conveniently add, delete and modify the timed task system through interaction, and the mobile robot does not need to add extra Hardware overhead.

DRAWINGS

Other features, objects, and advantages of the present application will become more apparent from the detailed description of the accompanying drawings.

1 shows a schematic structural diagram of a system for a timing task of a mobile robot according to an aspect of the present application;

2 is a schematic diagram of a timing task system for a mobile robot in an embodiment of the present application;

FIG. 3 illustrates a flow chart of a method for a timed task of a mobile robot provided in accordance with another aspect of the present application.

The same or similar reference numerals in the drawings denote the same or similar components.

Detailed ways

The present application is further described in detail below with reference to the accompanying drawings.

In a typical configuration of the present application, the terminal, the device of the service network, and the trusted party each include one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

The memory may include non-persistent memory, random access memory (RAM), and/or non-volatile memory in a computer readable medium, such as read only memory (ROM) or flash memory. Memory is an example of a computer readable medium.

Computer readable media includes both permanent and non-persistent, removable and non-removable media. Information storage can be implemented by any method or technology. The information can be computer readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read only memory. (ROM), electrically erasable programmable read only memory (EEPROM), flash memory or other memory technology, compact disk read only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, A magnetic tape cartridge, magnetic tape storage or other magnetic storage device or any other non-transportable medium that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include non-transitory computer readable media, such as modulated data signals and carrier waves.

FIG. 1 is a schematic structural diagram of a system for a timed task of a mobile robot according to an aspect of the present application. The system includes: a user interaction module 11, a task database module 12, a task triggering module 13, a task management module 14, and The service module 15, wherein the user interaction module 11 is configured to acquire timed task information set by the user, where the operation includes at least one of the following: adding, deleting, and modifying; here, the user may be at the terminal Equipment such as mobile phones, tablets and other mobile terminals or robots, through the graphical editing environment, add, delete and modify the timing tasks and determine the type of service triggered. The task database module 12 is configured to receive and save a timed task set by the user, and read by the task triggering module; where the task database receives and saves the scheduled task set by the user, and if necessary, the task triggering module reads take. The task triggering module 13 is configured to read the timed task from the task database module 12, and match the read timed task with the current timed task to determine whether to trigger the task; the task management module 14 a trigger task signal for receiving the task triggering module, determining scheduling and decision information of the timed task, and receiving a currently executed service end notification, updating the mobile robot state; further, the task management module 14 is configured to: And: performing scheduling and decision on the timed task based on a matching result of the timed task of the user in the database and the current timed task, and processing the multi-task superimposed, and pushing a signal for starting or ending the service. Here, the task management module 14 receives the signal of the task triggering module and performs task management, and performs control decision, especially for the case of multi-task superposition, which is the control center of the entire timed task system. The service module 15 is configured to execute a service corresponding to the timed task based on the scheduling and decision information of the timed task and the determined service type information, where the service type is a service mode of the mobile robot, such as automatic cleaning of the cleaning robot , fixed-point cleaning, fixed-point recharge, etc.

2 is a schematic diagram of a timing task system for a mobile robot according to an embodiment of the present application, wherein the system is mainly composed of an interaction system, a cloud timing task system, and a robot system, and mainly includes the user interaction module 11 and the task database described above. The module 12, the task triggering module 13, the task management module 14, and the service module 15 further include a communication module, a robot algorithm module, a peripheral module, a positioning drawing module, and a motion control module, wherein each module functions as follows:

The communication module is configured to establish communication between the terminal device, the network device, and the mobile robot to update the mobile robot state after transmitting the scheduled task information and receiving the currently executed service end notification. In an embodiment of the present application, the communication module exists in the interaction system, the cloud timing task system, and the robot system, and establishes communication between the mobile terminal and the cloud, and the robot to the cloud, and functions to transmit the timing task information. And when the mobile robot performs the scheduled task, if the current service is completed or the service duration arrives, the current service is ended, and the communication module receives the notification of ending the current service, and updates the state of the mobile robot.

The peripheral module is configured to collect, by using multiple sensors, the fusion information in the service process corresponding to the execution of the timing task. Here, the module includes a combination of multiple sensors, such as a drop sensor, an infrared sensor, a radar, a camera, a touch sensor, a wall sensor, etc., and also includes the output of the mobile robot, such as a screen, a speaker, and the like.

The positioning drawing module is configured to determine the environment map and the location information of the mobile robot according to the fusion information in the peripheral module. Here, the positioning and mapping module is based on the information of the multi-sensor fusion of the peripheral modules, constructs a map and performs autonomous positioning, so that the mobile robot recognizes the environment and recognizes the location of the environment in which it is located.

a robot algorithm module, configured to process the fusion information in the peripheral module based on the service type in the service module, and plan the mobile robot movement path according to the environment map in the positioning drawing module and the location information of the mobile robot, and implement the A service of a corresponding service type of a mobile robot. Here, the robot algorithm module processes the input data of the peripheral module based on the service type in the service module, and implements the specific service of the mobile robot.

And a motion control module, configured to control motion of the mobile robot based on an environment map in the positioning drawing module, position information of the mobile robot, and information of a moving path of the mobile robot in the robot algorithm module. In an embodiment of the present application, the motion control module uses the map and position information of the positioning drawing module, combined with the target or path information of the robot algorithm module, and controls the motor of the mobile robot by closed loop to realize smooth rotation, rotation, etc. of the mobile robot. motion.

In an embodiment of the present application, the robot algorithm module is further configured to: determine a corresponding task decision according to a specific situation in a service process collected in the peripheral module, and send the task decision to the motion control module. The robot algorithm module sends the fusion information collected by the peripheral module to the positioning drawing module to generate the environment map and the position information of the mobile robot, and uses the information generated by the positioning drawing module to plan the moving path of the mobile robot and send it to the motion control module. In the above process, if the peripheral module collects information and encounters special circumstances, such as collision, drop, floating, etc., the robot algorithm module adds the special situation collected by the peripheral module to the comprehensive decision to calculate the corresponding countermeasure and sends it to the motion control module.

In an embodiment of the present application, the task management module is configured to: acquire a push signal of a periodic operation of the mobile robot; generate a decision according to the timed task, time, and current service state, to control start, end, and restart Start any of the services. Here, the task triggering module periodically runs and pushes a signal to the task management module, and the task management module generates a decision according to the scheduled task, time, and current service state to control to start, end, and restart the new service in the service module.

The timed task system for the mobile robot described in the present application can enable the mobile robot to start and end the service periodically, and help the mobile robot realize the long-term automatic attendance of the unmanned intervention; the user can conveniently interact with the timed task system through interaction. Add, delete, and modify, while adding no additional hardware overhead to the mobile robot.

3 is a schematic flow chart of a method for a timed task of a mobile robot according to another aspect of the present application, the method comprising: steps S11 to S15,

In step S11, the scheduled task information of the user's operation setting is acquired, wherein the operation includes at least one of the following: adding, deleting, and modifying; here, the timing task is, for example, fixed-point cleaning of the mobile robot, in setting Automatic cleaning in the time period, the mobile robot is preferably a sweeping robot, and the timed task is a single task or a periodic task; by acquiring the user's operation, the interactive mode can be realized, and the user can add, delete and modify the timed task. The interaction mode may be an interaction of a mobile terminal application such as a mobile phone or a tablet or a mobile robot user interface interaction.

In step S12, the timed task of the user in the database is updated based on the set timed task information; here, the user adds, deletes, and modifies the timed task information through the user interaction module, and sends the obtained timed task set by the user to The cloud timed task system, the cloud timed task system modifies the task database and saves the timed tasks set by the user. Next, in step S13, the user's timed task in the database is synchronized based on the acquired request of the access timed task, and the timed task of the user in the database is matched with the current timed task to trigger the timed task; You can periodically access the cloud timed task system, synchronize the timed tasks in the database, match the current system time, and decide whether to trigger the timed task.

Then, in step S14, the service corresponding to the timed task is executed based on the scheduling and decision information of the timed task and the determined service type information; here, scheduling and decision making of the timed task, combined with the determined service type, Perform the service corresponding to the scheduled task. Finally, in step S15, if the current service is completed or the service duration arrives, the currently executed service is ended and the mobile robot state is updated. Here, when the mobile robot performs the service process corresponding to the timed task, if the current service is completed or the service duration arrives, the current service is ended, and a notification is sent to update the mobile robot state.

Further, after matching the timed task of the user in the database with the current timed task, the method includes: Step S14', based on the matching result of the user's timed task in the database and the current timed task, the timing Tasks are scheduled and decided, and processed during multitasking, pushing signals to start or end the service. Here, when the task management is performed based on the received signal of the trigger task, the multi-task superimposition is processed, and the signal of starting or ending the service is pushed to specifically execute the corresponding service.

Further, the method includes: Step S151, determining environment map and location information of the mobile robot according to the fusion information in the service process corresponding to the execution of the timing task, and planning the movement according to the environment map and the location information of the mobile robot The robot moves the path. In an embodiment of the present application, the environment map and the mobile robot position information are generated based on the collected fusion information, and the mobile robot movement path is planned using the generated environment map and the mobile robot position information.

Further, the method includes: Step S152, controlling motion of the mobile robot based on the environment map, location information of the mobile robot, and information of the mobile robot movement path. Here, the environment map, the position information of the mobile robot, and the information of the target or the movement path of the mobile robot are combined, and the motor of the mobile robot is controlled by the closed loop to realize smooth movement of the mobile robot such as straight line or rotation.

Further, the method further includes: Step S153, determining a corresponding task decision according to the fusion information in the service process corresponding to the execution of the timing task and the specific situation in the service process; controlling the mobile robot according to the corresponding task decision motion. In an embodiment of the present application, the fusion information in the service process corresponding to the scheduled task and the specific situation encountered in the service process, such as collision, drop, and floating, etc., are added to the comprehensive decision to calculate corresponding countermeasures. And control the movement of the mobile robot according to countermeasures, such as changing the smooth motion of the line.

Further, while performing the service corresponding to the timed task, acquiring a push signal of the periodic operation of the mobile robot; generating a decision according to the timed task, time, and current service state to control opening, ending, and restarting Any one of the services. In an embodiment of the present application, the periodic operation determines whether to trigger a task and pushes a trigger task signal, and generates a decision control according to the scheduled task, time, and current service state to start, end, and restart a new service.

In summary, through the timed task system of the mobile robot described in the present application, the following steps are completed to implement the timed task: Step 1: The user adds, deletes, and modifies the timed task information through the user interaction module, and is sent by the communication module to Cloud timing task system. Step 2: The cloud timed task system modifies the task database and saves the timed tasks set by the user. Step 3: The task triggering module periodically accesses the cloud timed task system through the communication module, synchronizes the timed tasks in the database, matches the current system time, and pushes the matching result to the task management module. Step 4: The task management module schedules and decides the timing task, and processes the multi-task superposition, and pushes the signal of starting or ending the service to the robot algorithm module. Step 5: The robot service module receives the signal of the task management module, determines the type of the service in combination with the service in the service module, and starts a specific service process. Step 6: The robot algorithm module sends the fusion information collected by the peripheral module to the positioning and mapping module to generate the environment map and the position information of the mobile robot, and uses the information generated by the positioning and mapping module to plan the moving path of the mobile robot and send it to the motion. Control module. Step 7: In step 6, if the peripheral module encounters special conditions, such as collision, drop, dangling, etc., the robot algorithm module adds the special case in the peripheral module to the comprehensive decision to calculate the corresponding countermeasure and sends it to the motion control module. Step 8: In step 6, the task triggering module periodically runs and pushes a signal to the task management module. The task management module generates decision control based on the scheduled task, time, and current service state to start, end, and restart the new service. Step 9: In step 6, if the current service is completed or the service duration arrives, the robot algorithm module ends the current service in the service module, and notifies the task management module and the communication module that the mobile robot state has been updated. Therefore, the mobile robot can be started and terminated periodically, and the mobile robot can realize the long-term automatic attendance of the unmanned intervention; the user can conveniently add, delete and modify the timed task system through interaction, and the mobile robot does not need to add extra Hardware overhead.

According to still another aspect of the present application, there is also provided a computer readable medium having stored thereon computer readable instructions executable by a processor to implement a method for a timed task of a mobile robot. For example, the computer readable instructions can be executed by a processor:

It will be apparent to those skilled in the art that various modifications and changes can be made in the present application without departing from the spirit and scope of the application. Thus, it is intended that the present invention cover the modifications and variations of the present invention.

It should be noted that the present application can be implemented in software and/or a combination of software and hardware, for example, using an application specific integrated circuit (ASIC), a general purpose computer, or any other similar hardware device. In one embodiment, the software program of the present application can be executed by a processor to implement the steps or functions described above. Likewise, the software programs (including related data structures) of the present application can be stored in a computer readable recording medium such as a RAM memory, a magnetic or optical drive or a floppy disk and the like. In addition, some of the steps or functions of the present application may be implemented in hardware, for example, as a circuit that cooperates with a processor to perform various steps or functions.

In addition, a portion of the present application can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide a method and/or technical solution in accordance with the present application. The program instructions for invoking the method of the present application may be stored in a fixed or removable recording medium, and/or transmitted by a data stream in a broadcast or other signal bearing medium, and/or stored in a The working memory of the computer device in which the program instructions are run. Herein, an embodiment in accordance with the present application includes a device including a memory for storing computer program instructions and a processor for executing program instructions, wherein when the computer program instructions are executed by the processor, triggering The apparatus operates based on the aforementioned methods and/or technical solutions in accordance with various embodiments of the present application.

It is obvious to those skilled in the art that the present application is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the present embodiments are to be considered as illustrative and not restrictive, and the scope of the invention is defined by the appended claims instead All changes in the meaning and scope of equivalent elements are included in this application. Any reference signs in the claims should not be construed as limiting the claim. In addition, it is to be understood that the word "comprising" does not exclude other elements or steps. A plurality of units or devices recited in the device claims may also be implemented by a unit or device by software or hardware. The first, second, etc. words are used to denote names and do not denote any particular order.

Claims

A method for a timed task of a mobile robot, wherein the method comprises:

Obtaining time-critical task information set by the user, where the operation includes at least one of the following: adding, deleting, and modifying;

Updating a timed task of the user in the database based on the set timed task information;

And synchronizing the timed task of the user in the database based on the obtained request for accessing the scheduled task, and matching the timed task of the user in the database with the current timed task to trigger the timed task;

Performing, according to the scheduling and decision information of the timed task and the determined service type information, a service corresponding to the timed task;

If the current service is completed or the service duration arrives, the currently executed service is terminated and the mobile robot status is updated.
The method of claim 1, wherein after matching the timed task of the user in the database with the current timed task, the method comprises:

The scheduling task is scheduled and determined based on the matching result of the user's timed task in the database and the current timed task, and is processed when the multi-task is superimposed, and the signal for starting or ending the service is pushed.
The method of claim 1 wherein said method comprises:

The environment map and the location information of the mobile robot are determined according to the fusion information in the service process corresponding to the execution of the timing task, and the mobile robot movement path is planned according to the environment map and the location information of the mobile robot.
The method of claim 3 wherein said method comprises:

Controlling the motion of the mobile robot based on the environment map, the position information of the mobile robot, and the information of the mobile robot movement path.
The method of claim 3, wherein the method further comprises:

Determining a corresponding task decision according to the fusion information in the service process corresponding to the execution of the timed task and the specific situation in the service process;

Controlling the motion of the mobile robot based on the corresponding task decision.
The method according to claim 1, wherein the performing the service corresponding to the timed task comprises:

Obtaining a push signal of the periodic operation of the mobile robot;

A decision is generated based on the scheduled task, time, and current service state to control the opening, closing, and restarting of any of the services.
A system for a timed task of a mobile robot, wherein the system comprises:

a user interaction module, a task database module, a task triggering module, a task management module, and a service module, wherein

The user interaction module is configured to acquire timed task information set by the user, where the operation includes at least one of the following: adding, deleting, and modifying;

The task database module is configured to receive and save a timed task set by a user, and read by the task triggering module;

The task triggering module is configured to read the timed task from the task database module, and match the read timed task with the current timed task to determine whether to trigger the task;

The task management module is configured to receive a trigger task signal of the task triggering module, determine scheduling and decision information of the timed task, and update the state of the mobile robot after receiving the currently executed service end notification;

The service module is configured to execute a service corresponding to the timed task based on the scheduling and decision information of the timed task and the determined service type information.
The system of claim 7 wherein said task management module is operative to:

The scheduling task is scheduled and determined based on the matching result of the user's timed task in the database and the current timed task, and is processed when the multi-task is superimposed, and the signal for starting or ending the service is pushed.
The system of claim 7 wherein said system comprises:

The peripheral module is configured to collect, by using multiple sensors, the fusion information in the service process corresponding to the execution of the timing task.
The system of claim 9 wherein said system comprises:

The positioning drawing module is configured to determine the environment map and the location information of the mobile robot according to the fusion information in the peripheral module.
The system of any of claims 8 to 10, wherein the system comprises:

a robot algorithm module, configured to process the fusion information in the peripheral module based on the service type in the service module, and plan the mobile robot movement path according to the environment map in the positioning drawing module and the location information of the mobile robot, and implement the A service of a corresponding service type of a mobile robot.
The system of claim 11 wherein said system comprises:

And a motion control module, configured to control motion of the mobile robot based on an environment map in the positioning drawing module, location information of the mobile robot, and information of a moving path of the mobile robot in the robot algorithm module.
The system of claim 12 wherein said robotic algorithm module is further

Corresponding task decisions are determined according to specific conditions in the service process collected in the peripheral module, and the task decisions are sent to the motion control module.
The system of claim 7 wherein said task management module is operative to:

Obtaining a push signal of the periodic operation of the mobile robot;

A decision is generated based on the scheduled task, time, and current service state to control the opening, closing, and restarting of any of the services.
The system of claim 7 wherein said system comprises:

The communication module is configured to establish communication between the terminal device, the network device, and the mobile robot to update the mobile robot state after transmitting the scheduled task information and receiving the currently executed service end notification.
A computer readable medium having stored thereon computer readable instructions executable by a processor to implement the method of any one of claims 1 to 6.