Content for  TS 22.104  Word version:  17.4.0

A.2.2  Factory automation  Word‑p. 29

A.2.2.1  Motion control

A motion control system is responsible for controlling moving and/or rotating parts of machines in a well-defined manner, for example in printing machines, machine tools or packaging machines.

A schematic representation of a motion control system is depicted in Figure A.2.2.1-1. A motion controller periodically sends desired set points to one or several actuators (e.g., a linear actuator or a drive) which thereupon perform a corresponding action on one or several processes (in this case usually a movement or rotation of a certain component). At the same time, sensors determine the current state of the process(es), e.g. the current position and/or rotation of one or multiple components, and send the actual values back to the motion controller. This is done in a strictly cyclic and deterministic manner, such that during one application cycle the motion controller sends updated set points to all actuators, and all sensors send their actual values back to the motion controller. Nowadays, typically Industrial Ethernet technologies are used for motion control systems.

Figure A.2.2.1-1: Schematic representation of a motion control system

Table A.2.2.1-1: Service performance requirements for motion control

Use case #

Characteristic parameter
Communication service availability: target value [%]

Communication service reliability: mean time between failures

End-to-end latency: maximum

Service bitrate: user experienced data rate

Influence quantity
Message size [byte]

Transfer interval: lower bound

Transfer interval: upper bound

Survival time

UE speed

# of UEs

Service area (note)

---

1

99.999 to 99.999 99

~ 10 years

< transfer interval value

–

50

500 μs - 500 ns

500 μs + 500 ns

500 μs

≤ 72 km/h

≤ 20

50 m x 10 m x 10 m

2

99.999 9 to 99.999 999

~ 10 years

< transfer interval value

–

40

1 ms - 500 ns

1 ms + 500 ns

1 ms

≤ 72 km/h

≤ 50

50 m x 10 m x 10 m

3

99.999 9 to 99.999 999

~ 10 years

< transfer interval value

–

20

2 ms - 500 ns

2 ms + 500 ns

2 ms

≤ 72 km/h

≤ 100

50 m x 10 m x 10 m

---

---

Use cases one to three

Characteristic parameters and influence quantities for a communication service supporting the cyclic interaction described above.

A.2.2.2  Control-to-control communication  Word‑p. 31

Control-to-control communication, i.e., the communication between different industrial controllers is already used today for different use cases, such as:

• large machines (e.g., newspaper printing machines), where several controls are used to cluster machine functions, which need to communicate with each other; these controls typically need to be synchronised and exchange real-time data;
• individual machines that are used for fulfilling a common task (e.g., machines in an assembly line) often need to communicate, for example for controlling and coordinating the handover of work pieces from one machine to another.

Typically, a control-to-control network has no fixed configuration of certain controls that need to be present. The control nodes present in the network often vary with the status of machines and the manufacturing plant. Therefore, hot-plugging support for different control nodes is important and often used.

Table A.2.2.2-1: Service performance requirements for control-to control communication in motion control

Use case #

Characteristic parameter
Communication service availability: target value in %

Communication service reliability: mean time between failures

End-to-end latency: maximum

Influence quantity
Message size [byte]

Transfer interval

Survival time

UE speed

# of UEs

Service area (note 1)

---

1 (note 2)

99.999 9 to 99.999 999

~ 10 years

< transfer interval value

1 k

≤ 10 ms

10 ms

stationary

5 to 10

100 m x 30 m x 10 m

2 (note 2)

99.999 9 to 99.999 999

~ 10 years

< transfer interval value

1 k

≤ 50 ms

50 ms

stationary

5 to 10

1,000 m x 30 m x 10 m

---

---

Use case one

Control-to-control communication between different motion (control) subsystems, as addressed in subclause A.2.2.1. An exemplary application for this is large printing machines, where it is not possible or desired to control all actuators and sensors by one motion controller only.

Use case two

Control-to-control communication between different motion (control) subsystems. Exemplary application for this are extra-large machines or individual machines used for fulfilling a common task (e.g., machines in an assembly line).

A.2.2.3  Mobile robots

Mobile robots and mobile platforms, such as automated guided vehicles, have numerous applications in industrial and intra-logistics environments and will play an increasingly important role in the Factory of the Future. A mobile robot essentially is a programmable machine able to execute multiple operations, following programmed paths to fulfil a large variety of tasks. This means, a mobile robot can perform activities like assistance in work steps and transport of goods, materials and other objects. Mobile robot systems are characterised by a maximum flexibility in mobility relative to the environment, with a certain level of autonomy and perception ability, i.e., they can sense and react with their environment.

Autonomous guided vehicles are a sub-group of mobile robots. These vehicles are driverless and used for moving materials efficiently within a facility. A detailed overview of the state of the art of autonomous-guided-vehicle systems is provided elsewhere in the literature [16].

Mobile robots are monitored and controlled from a guidance control system. Radio-controlled guidance control is necessary to get up-to-date process information, to avoid collisions between mobile robots, to assign driving jobs to the mobile robots, and to manage the traffic of mobile robots. The mobile robots are track-guided by the infrastructure with markers or wires in the floor or guided by own surround sensors, like cameras and laser scanners.

Mobile robot systems can be divided in operation in indoor, outdoor and both indoor and outdoor areas. These environmental conditions have an impact on the requirements of the communication system, e.g., the handover process, to guarantee the required cycle times.

Table A.2.2.3-1: Service performance requirements for mobile robots

Use case #

Characteristic parameter
Communication service availability: target value [%]

Communication service reliability: mean time between failures

End-to-end latency: maximum

Service bitrate: user experienced data rate

Influence quantity
Message size [byte]

Transfer interval: lower bound

Transfer interval: target value (note)

Transfer interval: upper bound

Survival time

UE speed

# of UEs

Service area

---

1

> 99.999 9

~ 10 years

< target transfer interval value

–

40 to 250

- < 25 % of target transfer interval value

1 ms to 50 ms

+ < 25 % of target transfer interval value

target transfer interval value

≤ 50 km/h

≤ 100

≤ 1 km²

2

> 99.999 9

~ 1 year

< target transfer interval value

–

15 k to 250 k

- < 25 % of target transfer interval value

10 ms to 100 ms

+ < 25 % of target transfer interval value

target transfer interval value

≤ 50 km/h

≤ 100

≤ 1 km²

3

> 99.999 9

~ 1 year

< target transfer interval value

–

40 to 250

- < 25 % of target transfer interval value

40 ms to 500 ms

+ < 25 % of target transfer interval value

target transfer interval value

≤ 50 km/h

≤ 100

≤ 1 km²

4

> 99.999 9

~ 1 week

10 ms

> 10 Mbit/s

–

–

–

–

–

≤ 50 km/h

≤ 100

≤ 1 km²

---

---

Use case one

Periodic communication for the support of precise cooperative robotic motion control (transfer interval: 1 ms), machine control (transfer interval: 1 ms to 10 ms), co-operative driving (10 ms to 50 ms).

Use case two

Periodic communication for video-operated remote control.

Use case three

Periodic communication for standard mobile robot operation and traffic management.

Use case four

Real-time streaming data transmission (video data) from a mobile robot to the guidance control system.