How can I get a VirtualFile from a path relative to 'workspace'?

There's no 'workspace' concept in IntelliJ IDEA. See
com.intellij.openapi.project.Project#getBaseDir(), getBasePath()

com.intellij.openapi.module.Module#getModuleFile(), getModuleFilePath()
com.intellij.openapi.vfs.LocalFileSystem#findFileByPath(),
com.intellij.openapi.vfs.VfsUtilCore#findRelativeFile()
etc.

I know workspace concept dosn't exist that's way i used quote. But the question remains, how can i get the VirtualFile from that String?
In eclipse it can be done like this:

public Object getFile(String path) {
        return ResourcesPlugin.getWorkspace().getRoot().findMember(path);
    }

Did you look at the methods I listed? I think it is possible to guess an answer even without looking in docs for those methods, just by reading the names.

Project.getBaseDir()is of no use, because it returns the parent directory of the .ipr file. And i can have Module1 in C: and Module2 in D: (Module1 has nothing in common with the .ipl file path)

To find required module use ModuleManager.
Module file (*.iml) and module content roots can be located on different drives as well, so you'll probably need to get content or source roots using ModuleRootManager.

I haven't found a nice solution to work with relative path. So i used Alexander Doroshko sugetions and absolute paths.

VirtualFile[] vFiles = ProjectRootManager.getInstance(this.project).getContentRoots();


VirtualFile stateMachineConfig = vFiles[0].findChild("stateConfig.json");

or

VirtualFile controllerFolder = vFiles[0].findFileByRelativePath("scripts/hov/controller");