Sensor Query Schedule and Sensor Noise Covariances for Accuracy-constrained Trajectory Estimation

TL;DR

This paper presents a method to determine optimal sensor query schedules and noise covariances to meet specific trajectory estimation accuracy requirements, balancing sensor performance and resource constraints.

Contribution

It introduces a semidefinite programming approach to estimate sensor parameters needed for accuracy-constrained trajectory estimation, validated through simulations and real experiments.

Findings

Sensor schedules and covariances can be optimized for desired accuracy.

The method identifies unachievable accuracy scenarios given system constraints.

Validated effectiveness in both simulation and real-world experiments.

Abstract

Trajectory estimation involves determining the trajectory of a mobile robot by combining prior knowledge about its dynamic model with noisy observations of its state obtained using sensors. The accuracy of such a procedure is dictated by the system model fidelity and the sensor parameters, such as the accuracy of the sensor (as represented by its noise covariance) and the rate at which it can generate observations, referred to as the sensor query schedule. Intuitively, high-rate measurements from accurate sensors lead to accurate trajectory estimation. However, cost and resource constraints limit the sensor accuracy and its measurement rate. Our work's novel contribution is the estimation of sensor schedules and sensor covariances necessary to achieve a specific estimation accuracy. Concretely, we focus on estimating: (i) the rate or schedule with which a sensor of known covariance must generate measurements to achieve specific estimation accuracy, and alternatively, (ii) the sensor covariance necessary to achieve specific estimation accuracy for a given sensor update rate. We formulate the problem of estimating these sensor parameters as semidefinite programs, which can be solved by off-the-shelf solvers. We validate our approach in simulation and real experiments by showing that the sensor schedules and the sensor covariances calculated using our proposed method achieve the desired trajectory estimation accuracy. Our method also identifies scenarios where certain estimation accuracy is unachievable with the given system and sensor characteristics.