Instrumentation & Control Systems

Prior to the late 1940’s, simple controls like a mechanical governor for a diesel driven electric generator were used to achieve reasonably constant power system frequency. Today we have sophisticated computer-based energy management systems for management of the electric poser systems. Modern automotive vehicles are full of control systems. Other control systems incorporate wire based or wireless communication systems. These can be as simple as for a remote control to switch channels on a TV to the use of global positioning systems for guidance of missiles. The controls systems of today or mostly electrical/electronic but can also be implemented using pneumatic or hydraulic technologies.

Analyzing the performance of the automatic control systems requires access to sophisticated mathematical tools and specialized knowledge how to use such tools and how to evaluate the results. Thus, control system engineering has evolved into a specialized engineering discipline devoted to study of the dynamics of the systems and to improve the performance of the systems. An example of a sophisticated control system is found in hard disk drives and optical disk drives. Various control loops are used in these devices to perform rotational speed control, seeking, track-following, and error recovery. Exponent has expertise in understanding the sensors, processors, and actuators in hard disk drives.

Exponent engineers and scientists have experience from all aspects of instrumentation and control systems design, validation, failure analysis and performance dispute resolution. This includes:


  • Sensor design and failure analysis 
  • Computer and communication system architectures and system design
  • Software development, testing and validation
  • Analysis of the control system’s dynamic performance and design of control algorithms 
  • Failure analysis of the control systems taking into account both the hardware and the software subsystems 
  • Communication system performance issues 
  • Human factors aspects of control systems 
  • Resolution of disputes related to expected performance versus actual performance of control systems 
  • Intellectual property related to control systems

Examples of controls systems work performed by Exponent:


  • Control system design error causing process to remain in an endless loop
  • Construction delay related to specification issues for a pneumatic control system intended for an oil platform application
  • System integration testing causing an outage of a refinery
  • Power system blackout caused by unanticipated disturbances imposed on a control and protective relay system at an electric utility 
  • Accidents alleged to have been caused by automatic door control systems
  • Cruise control for automotive vehicles
  • Controls for computer hard disk drives
  • Controls for automatic transfer between utility power and emergency stand-by power
  • Control system role in an accident at a wastewater treatment plant

Professionals