Failure force sensors

In the near future it will be possible to monitor the status of heart failure using sensors incorporated in the newest generations of defibrillators. Major manufacturers of these devices have put in them the ability to monitor such parameters as heart rate variability, pressure in the right ventricle and force of contraction of the heart as well as many other parameters that are of as yet uncertain significance. As experience with using these data increases the ability to ascertain their utility in the management of patients will increase. 

The vision of braking and steering by wire will demand new, extremely reliable sensors. Even in early implementations of steer-by-wire systems, in which manual control can override any system failure, more than one sensor is normally used for the sake of redundancy. Many of the sensor principles required are already established in the market, including steering-angle sensors (e.g., for vehicle dynamics control) and pedal-position sensors. Mechanical action or feedback control, however, will drive the emergence of torque and force sensors. 

A force sensor combines a structure that responds to force changes with a sensor that converts these changes into a signal. A torque sensor similarly consists of a torsion or tension element detector, but it also has to transmit the force. Consider the torque for a electric power steering system any failure would immediately mean loss of control of the vehicle, so this must be avoided under all circumstances. Steering column torque requires careful finite element calculation, durability and performance testing to failure, and validation. 

The reactor trip and main loop shutdown instrumentation hardware and sensors are designed to withstand the forces imposed by the QBE and SSE so as to remain functional during and after either earthquake. System failures which could result in loss of function are identified as follows ... 

Fail-safe modes of the devices are shown by the arrow symbols of the actuators. For the sensors the design should specify upscale burnout modes for both temperature sensors since failures upscale would force the control system and the SIS into a safe mode for the process. 

---