The Internet is littered with articles about Industry 4.0. Adoption of digital industrial processes have accelerated since the German government led this initiative to maintain national industrial prowess. For example, with digital twins and modular flexible systems. One of the main features of Industry 4.0 is interoperability for mobile cyber-physical systems. Examples include mobile robots, automated guided vehicles (AGV) and manufacturing infrastructure. For these digital industrial processes to run over wireless infrastructure, the communications technology must deliver against strict application requirements for performance and reliability.
Such articles often leave out critical details, such as what is actually needed from the network. I always ask the question: What are the different options to serve these application requirements? This blog is the first in a series, bringing a lens on robots and AGV, dissecting the application flow and a little detail on why the serving wireless medium must behave in a particular way to support it. Subsequent blogs will address the remaining of the three use-cases:
1) Mobile Robots and Automated Guided Vehicles
2) Manufacturing logistics
3) Process automation monitoring
Mobile Robots and Automated Guided Vehicles
These machines are programmed to execute multiple tasks, with predefined outcomes, such as handling some equipment or material. Modern AI techniques allow dynamic behaviours such as collision avoidance and route decision making on the fly. I have also seen cooperating interactions with other machines to achieve a particular outcome.
Edge Compute Adoption
The communication flow for these devices depends upon the level of edge compute adoption in the system. Some devices will have all intelligence and decision-making capabilities on board, and others will utilise a centralised control system. There is a spectrum of possibilities due to the varying functional building block locations in the edge architecture. For this blog, I will consider the network traffic carrying interactions external to the mobile robot system, akin to the on-board intelligence model.
Communication flows can exist between mobile robots, to pass real-time telemetry information, pulling in primary data for route finding and collision avoidance algorithms. Additional flows exist to interact with third-party devices, such as any other moving object (crane, forklift, truck), or static objects that can interact (gates, doors, ramps, rails, manufacturing machines). Onboard safety processes may run that also interact with external systems. All these flows are real-time and deterministic, meaning control and telemetry messages must be received within a specific window for real-time processing. The AGV actions may be part of broader industrial processes across the facility.
Because of the criticality of all the flows to achieve successful real-time physical operation in a dynamic environment, mobile robots and AGV have extremely strict and sensitive network service requirements, looking something like this:
Availability: Between five and several nines
Determinism: Varying transmission window depending on autonomous independence from applications ‘over the air’, possibly down to microsecond measurements at the most demanding
Reliability: Continued operation regardless of node and/or path failure
Synchronicity: Clocking systems must be accurately synchronised to sub-microsecond level
Traffic Types: Mixture of critical traffic, non-critical telemetry, and high-definition video
Drivers for technology decisions
Some use-cases can be solved in multiple ways, with different technologies. Secondly, technology selection is usually not the only driver for the final architecture. Especially in a brownfield environment, there may be existing technologies and processes in place that are either adopting or driving the new implementation of wireless access.
Some of these additional drivers may be:
- To use existing investments in wireless solutions
- Adhering to the technical strategy of the plant leadership team
- Optimising total cost of ownership by solving multiple use-cases with one technology
- Desire for simplicity and standardisation
- Engineering reticence to remove reliable wired systems
- Financial budgeting constraints
- Available skills and existing technical debt
- Interoperability between the industrial automation solution and the options for connecting systems wirelessly.
Each time a new architecture is selected or enhanced, a very careful analysis of all these factors and the perceived risks in available options should be assessed. Business cases should use empirical evidence and detailed design considerations where possible.
I have not written these blogs to give you definitive answers on which technology is right for your use-case and how to proceed. You should make your own educated opinion on that. This is because of the unknown variables and complexity involved in every deployment scenario. Considerations must be made for tailored radio planning, brownfield systems, and specialist design to maximise the wireless performance and availability.
Cisco brings use-case solutions and reference architectures that enable specific business outcomes for our customers. It important to take a tailored approach each time, to ensure all aspects of your context are accounted for. We will focus on your business requirements, bringing a toolbox of options to suit your application, including: Indoor, outdoor, and ruggedised WiFi, Ultra Reliable Wireless, Private 5G, and LoRaWAN.
Connect with your Cisco account team to discuss your industrial processes, and options for wireless connectivity in your manufacturing operations. The Cisco account team will then help you with a deep dive on your business requirements. We will help you understand the options open to you for digitising processes over wireless.
Finally, over to you!
I’m intrigued to know if you have considered or are already using wireless communications for your robot and AGV systems. I’d love to hear your perspective and experiences.
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