Henk Luinge

Drift-free dynamic height sensor using MEMS IMU aided by MEMS pressure sensor

We demonstrate a low-cost, low-power, and small form factor solution to drift-free high-resolution vertical positioning by fusing MEMS accelerometers with MEMS barometric altimeter. In this system, the highly responsive but drift-prone aspect of the MEMS accelerometers is stabilized by barometric altimeter and high-fidelity height tracking is achieved. Typical vertical human movements such as walking up or down a staircase can be tracked in real-time with this system. The height tracking performance is benchmarked against a reference system using a tactical-grade IMU and an error analysis is performed.

Tightly coupled UWB/IMU pose estimation

In this paper we propose a 6DOF tracking system combining Ultra-Wideband measurements with low-cost MEMS inertial measurements. A tightly coupled system is developed which estimates position as well as orientation of the sensor-unit while being reliable in case of multipath effects and NLOS conditions. The experimental results show robust and continuous tracking in a realistic indoor positioning scenario.

Daily-life monitoring of stroke survivors motor performance: The INTERACTION sensing system

The objective of the INTERACTION Eu project is to develop and validate an unobtrusive and modular system for monitoring daily life activities, physical interactions with the environment and for training upper and lower extremity motor function in stroke subjects. This paper describes the development and preliminary testing of the project sensing platform made of sensing shirt, trousers, gloves and shoes. Modular prototypes were designed and built considering the minimal set of inertial, force and textile sensors that may enable an efficient monitoring of stroke patients. The single sensing elements are described and the results of their preliminary lab-level testing are reported.

A Full Body Sensing System for Monitoring Stroke Patients in a Home Environment

Currently, the changes in functional capacity and performance of stroke patients after returning home from a rehabilitation hospital is unknown to a physician, having no objective information about the intensity and quality of a patient’s daily-life activities. Therefore, there is a need to develop and validate an unobtrusive and modular system for objectively monitoring the stroke patient’s upper and lower extremity motor function in daily-life activities and in home training. This is the main goal of the European FP7 project named “INTERACTION”. A complete full body sensing system is developed, whicj integrates Inertial Measurement Units (IMU), Knitted Piezoresistive Fabric (KPF) strain sensors, KPF goniometers, EMG electrodes and force sensors into a modular sensor suit designed for stroke patients. In this paper, we describe the complete INTERACTION sensor system. Data from the sensors are captured wirelessly by a software application and stored in a remote secure database for later access and processing via portal technology. Data processing includes a 3D full body reconstruction by means of the Xsens MoCap Engine, providing position and orientation of each body segment (poses). In collaboration with clinicians and engineers, clinical assessment measures were defined and the question of how to present the data on the web portal was addressed. The complete sensing system is fully implemented and is currently being validated. Patients measurements start in June 2014.

Robust height tracking by proper accounting of nonlinearities in an integrated UWB/MEMS-based-IMU/baro system

This paper presents an integrated tracking system combining a MEMS-based-IMU, a UWB system and a barometer. The complementary features of the technologies make the integrated system provide a robust position and orientation estimate. The nonlinearity problem inherent in the strapdown integration solution is taken into account in the problem formulation and the methods. The use of the barometer and the incorporation of an EKF using a second order Taylor series approximation are shown to be effective in obtaining robust and reliable tracking estimates overall and in particular for the vertical channel.

Integrating GPS/MEMS-based-IMU with single GPS baseline for improved heading performance

In a GPS/IMU integrated navigation system, problems are often encountered during periods of low-observability of heading considered essential in many applications such as antenna steering platforms, airborne navigation, swarm navigation, mobile mapping and harbor navigation. This paper proposes the use of a GPS/MEMS-based-IMU with a single GPS baseline measurement update in an EKF framework for an improved heading performance. The single GPS baseline update makes use of GPS-L1 only carrier-phase measurements from two antennas mounted 1 m apart along the direction of motion of the platform. The epoch-to-epoch double-difference carrier-phase measurements formed is resolved for the integer ambiguity set and is incorporated directly in an EKF measurement update. The performance of the navigation system is demonstrated using data collected in an urban environment with sensors rigidly mounted on the rooftop of a van.