Electrical and Systems Engineering in Washington University in St. Louis

Experimental Study of Robotic Assembly
and Force Control Tasks

ESE 499 Undergraduate Senior Design Project
Supervising Instructor: Professor Eftychios Christoforou
Student: Sie Deen Lau
siedeen @ gmail.com
XR-4 Robotic Arm
Robotic Assembly with
Insertion Compliance Device
Force Feedback Control


This website discusses the examination of two industrial robot applications. The first is a robotic assembly using passive compliant devices and the second is a contact force control application. For each problem an end-effector device was designed, built and tested using a robotic manipulator with five degrees of freedom. The devices are presented together with the experimental results.

* A report of this senior design project is also available here in PDF format.


Robotic applications are widely used in research laboratories and industries to automate processes and reduce human errors. Some of the tasks performed by robots include assembly lines and motions that require force control with feedback to its controller. This website describes my senior design project that examines both tasks using a robotic manipulator with five degrees of freedom.

The report is organized as follows:

  • Description of the robotic manipulator
  • Robotic assembly using a passive compliance device
  • Contact force control application using an active compliance device
  • Safe operation of the robotic system
  • Conclusion of the experimental study
  • Program code & links to external sources
To investigate the robotic applications for the assembly and force feedback control tasks, I used the XR-4 robotic arm, as seen in Figure 1. Active and passive compliant devices were also designed to demonstrate the two tasks.

In an assembly line, a robotic manipulator is often assigned to move an object from one position to another. One example of this application is in a research laboratory where pipets are used to transport fluid substances from vials to a row of wells on a plate. The automated process results in faster completion time with minimal errors and downtime. On the left navigation, Robotic Assembly with Insertion Compliance Device describes the application of an assembly task where two components are mated together with perfect alignment.

     Figure 1: XR-4 robotic arm in
     home position

Force Feedback Control describes the implementation of robotic manipulators with force feedback control. This design is necessary when performing tasks that require a pre-determined force to be applied onto a working surface. Applications of the force control mechanism can be seen in manufacturing environments, an example of which is plants where marble surfaces are polished by machines. The use of force feedback control is demonstrated in this paper in two different manipulation scenarios; tracking a path on a level surface, as well as uphill downhill surfaces.

* To view PDF files, you'll need Acrobat Reader. Download for free at

Home | XR-4 Robotic Arm | Robotic Assembly with Insertion Compliance Device | Force Feedback Control

Dept. of Electrical & Systems  Engineering
Bryan 201, Box 1127,
1 Brookings Drive
St. Louis, MO-63130
Tel: (314) 935-5565
Contact Sie Deen at:
siedeen @ gmail.com
School of Engineering and Applied Sciences
Washington University in St. Louis.