How do robots understand and execute human natural language instructions?

Hey, that's an interesting question! Many people find it amazing that robots can understand human speech. Actually, there's a pretty complex process behind it, but I'll try to explain it in simple terms. You can think of it as a process of "translation" plus "action."

The whole process can generally be divided into these four steps:

1. "Listening": Turning Sound into Text

• This is the first and most fundamental step. The robot receives your spoken voice through a microphone. However, the robot itself doesn't understand sound; it only understands data.
• So, internally, it has a system called Automatic Speech Recognition (ASR). This system is similar to the voice input feature on your phone. Its task is to convert your voice, for example, "Pour me a glass of water," into text that a computer can read – "Pour me a glass of water."

2. "Understanding": Comprehending Your Intent from Text

• This is the most crucial and "intelligent" step. Now the robot has the text "Pour me a glass of water," but how does it know what to do with it?
• This is where Natural Language Processing (NLP) and Natural Language Understanding (NLU) technologies come into play. You can think of this as the robot's "brain." This "brain" is fed vast amounts of books, conversations, and data for "learning," and it analyzes the sentence:
  • Intent Recognition: Words like "help me" and "pour" combined likely indicate a "service request" intent, with the specific action being "pouring water."
  • Entity Extraction: It identifies key information in the sentence, such as "water" as the object of the action and "glass" as the target container.
• In essence, this step converts vague, colloquial human expressions into a structured command, similar to: "Command: Pour water; Target: Glass."

3. "Thinking": Planning How to Act

• The robot's brain now knows the goal is to "pour water into a glass," but it can't do it in one go. Its body (robotic arm, wheels) can only execute very simple commands, such as "move wheels forward 10 cm," "raise arm 5 degrees," or "open gripper."
• Therefore, it needs a Task Planning module. This module acts like a project manager, breaking down the large task of "pouring water" into a series of executable smaller steps:
  1. Use the camera to locate the "kettle."
  2. Plan a route and move next to the "kettle."
  3. Extend the robotic arm, adjust its posture, and grasp the "kettle."
  4. Use the camera to locate the "glass."
  5. Move next to the "glass."
  6. Raise the robotic arm, tilt the "kettle," and simultaneously monitor the water level using vision and sensors to prevent overflow.
  7. Once pouring is complete, put the "kettle" back.
  8. Return to the initial position.

4. "Acting": Executing the Actions

• This is the final step, turning the idea into reality. The robot will follow the series of small steps planned above, using its control system to drive its motors and joints, completing each action one by one.
• During this process, it continuously uses its various sensors (e.g., cameras, force sensors) to get feedback, which is called closed-loop control. For example, when pouring water, it will keep an eye on the glass to ensure no water spills; when grasping the kettle, it will use sensors to perceive pressure, ensuring it grips firmly without crushing it.

So, to summarize, the entire process is:

Your words (sound) → Text → Structured command (I understand) → A series of specific steps (I've planned how to do it) → Robot executes actions (I'm doing it now)

This is like teaching a child who knows nothing about cooking but is very obedient how to make a dish. You can't just say, "Make scrambled eggs with tomatoes." You have to tell them: First, go to the fridge and get two eggs and tomatoes; second, crack the eggs into a bowl and whisk them; third... Robots also need such detailed "recipes" to get work done.

I hope this explanation makes it easier for you to understand!