Linear inductive differential position sensors such as the linear variable differential transformer (LVDT) and the differential variable reluctance transducer (DVRT) are used extensively in a variety of applications due to their rugged, inexpensive design and compact size. Both the LVDT and DVRT are proficient at measuring the position of slow moving, or stationary objects, but become progressively more inaccurate as the speed of the object being measured increases. The variable reluctance differential solenoid transducer (VRDST) was recently developed, and shown to be capable of concurrently performing a measurement that is accurate at low speeds and a measurement that is accurate at high speeds. The VRDST was able to combine these two measurements using a complementary filter to create a single wide-bandwidth measurement. However, the large cost and small stroke-to-length ratio of the VRDST limits its practical viability.
This thesis presents a novel variation of the VRDST called the ironless-stator variable reluctance differential solenoid transducer (ISVRDST). The ISVRDST removes the ferromagnetic stator used by the VRDST to reduce the overall size and cost of the sensor. Finite element analysis (FEA) and analytical simulations are used to design the ISVRDST and predict its performance. A proof-of-concept prototype is fabricated and used to experimentally validate the analytical models and simulation results as well as compare its performance against the VRDST prototype. The ISVRDST is shown to be capable of robustly utilizing the complementary filter measurement pioneered by the VRDST, while having a 3.5 times larger stroke-to-length ratio, a 6.8 times larger stroke-to-width ratio, and while costing over 100 times less. Additionally, the ISVRDST is compared against the LVDT and DVRT and is found to have a comparable size, cost and performance while having a measurement bandwidth over 250 times larger.