I am trying to understand if robotic process automation is a field which requires expertise in machine learning. Does the algorithm behind rpa use machine learning expect from OCR?
Yes, rpa is AI. In particular, applied AI.
The definition of rpa in wiki is:
Robotic process automation (or RPA) is an emerging form of clerical process automation technology based on the notion of software robots or artificial intelligence (AI) workers.
Moreover, look at this characteristics of rpa:
The paradigm, in summary, is that a software robot should be a virtual worker who can be rapidly "trained" (or configured) by a business user in an intuitive manner which is akin to how an operational user would train a human colleague.
If we talk about training or learning, we talk about AI.
In the context of IT systems, "Robotic Process Automation" (RPA) is a term often used to describe a technique where software systems are integrated or work processes are automated through the existing user interface of the applications rather than writing new software to provide integration points.
In that context, RPA has nothing to do with AI or machine learning. In most cases, it does not even require OCR.
For an example of a common use case, let's say you have an old mainframe IT systems for tracking your subscriptions and a new website to let people order subscriptions from their phone.
In this case you might create an "RPA" job that opens the list of new subscription requests from the website and for each of them opens the old application, clicks of the "new subscription" button, click on the "Customer Name" field, pastes the name, clicks "Customer address" and pastes in the address etc.
In some cases, the RPA job will be exposed as a service with an API that can be called by the new application, so it can dump data directly into the old application. The benefit is that it can do this without any changes to the old application.
It is attractive because defining the steps of copy this, click that can often be defined in visual tools by non-programmers very quickly and at much lower cost than setting up a systems integration project to connect the two systems and because integration through the existing user interface does not require any changes to the application.
In this way, it is similar in spirit to how Excel allows non-programmers to automate calculations by writing formulae and thus automating their spreadsheets.
You will often see RPA proponents putting some AI buzzwords into their presentations but from what I have seen in industry RPA is mostly just a visual scripting technique that is easy to learn and easy to apply.