# Distance Navigation

When using distance navigation, the robot drives straight for a specific distance, and then turns to start driving in a new direction. The robot's path is programmed as an ordered sequence of specific distances and turns.

* **ADVANTAGE**:  The robot can be programmed to follow any path needed (i.e., path is not defined by lines or markers).
* **DISADVANTAGE**:  The robot's turns may not be perfectly accurate every time. After making several turns, the robot might be off-course from its intended path.

Distance navigation is similar to the directions that a mapping app might give you to drive to a destination (such as "Continue for 5 miles, and then turn right...").

## Example Task Scenario

In this task scenario, a hospital lab delivery robot will navigate through the hospital hallways (red rectangles are cardboard boxes representing walls) to an nurse's station in the hallway (labeled as "A"), pick up blood samples (simulated step), and deliver the samples to the hospital lab for analysis (labeled as "Start").

For the purposes of the demonstration, the distances traveled are obviously much shorter than a real hospital environment.

![](/files/-LRmdFHOJ-QxBwrIKaHx)

## Example Code

Here is a possible way to code a custom function to perform this task scenario:

```cpp
void task1() {
  // Example of Distance Navigation

  // drive from Start to Nurse Station A
  driveDistance(24);
  pivotAngle(-90); // turn left
  driveDistance(48);
  pivotAngle(90); // turn right
  driveDistance(18);

  // Simulated Step: pause and pick up samples at Station A
  pauseRobot(); // wait until button pressed

  // turn around and drive back to Start
  pivotAngle(180); // turn around
  driveDistance(18);
  pivotAngle(-90); // turn left
  driveDistance(48);
  pivotAngle(90); // turn right
  driveDistance(24);

  // Simulated Step: Samples are delivered to lab at Start
  doubleBeep();

  // at end of this task, reset for next task
  started = false;
  nextTask = 2;
}
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.idew.org/code-robotics/references/navigation-modes/distance-navigation.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.