WebDriverException: Message: 'chromedriver' executable needs to be in PATH

Question

I'm trying to learn RobotFramework, and this the first code:

* Setting * Library SeleniumLibrary

* Test Cases *
FirstSeleniumTest Open Browser https://google.com chrome Close Browser

but I received this failure error:

WebDriverException: Message: 'chromedriver' executable needs to be in PATH. Please see https://sites.google.com/a/chromium.org/chromedriver/home

I have tried almost everything what I could find by search, the chromedriver is in my /usr/local/bin/ and the project itself also /Users/arash/Documents/SeleniumDrivers

the echo $PATH is: /Library/Frameworks/Python.framework/Versions/3.7/bin:/Library/Frameworks/Python.framework/Versions/3.7/bin:/usr/bin:/usr/sbin:/bin:/usr/local/bin:/sbin:/opt/x11/bin:/Users/arash/Documents/SeleniumDrivers

I have tried brew, .bash, /etc/paths adding too.

please help me to figure out what is the problem.

Eclips screenshot