Innovative Navigation Schemes for State and Parameter Estimation During Mars Entry

Abstract

Accurate navigation systems are required in the scope of Mars precision landing missions. This paper reviews some assumptions of the literature concerning the availability of the vehicle states for guidance during its atmospheric entry on Mars. It is demonstrated that currently used measurements are not sufficient to get complete observability of the entry dynamics. Therefore, four innovative measurement scenarios based on radio ranging are proposed to resolve the observability issue. The analyses and simulations show that the addition of the range measurements from known references helps to estimate accurately the position states along with some critical model parameters, contrary to inertial measurement unit navigation alone. Finally, the addition of the range measurement from a secondary free-falling dummy vehicle with known aerodynamics also ensures the observability of aerodynamic parameters of the lander vehicle. Nomenclature A, B, C, D = state-space matrices a B = acceleration components in the body frame, m=s 2 B = ballistic parameter, m 2 =kg C D = aerodynamic drag coefficient C L = aerodynamic lift coefficient D = aerodynamic drag force, N d = aerodynamic drag deceleration, m=s 2 g = gravitational acceleration, m=s 2 h = altitude, m h s = atmospheric scale height, m h 0 = reference altitude, m L = aerodynamic lift force, N L=D = lift-to-drag ratio m = vehicle mass, kg Q o = observability matrix q = dynamic pressure, kg=m s 2 R e = equatorial radius, m r = radial distance, m S = aerodynamic surface, m s = downrange, m t = time. s u = input vector v = inertial velocity, m=s 0= trim angle of attack, rad = flight-path angle, rad = latitude, rad = longitude, rad M = Mars gravitational constant, m 3 =s 2 = atmospheric density, kg=m 3 0 = atmospheric reference density, kg=m 3 = bank angle, rad = azimuth (clockwise from north), rad ! B = angular rate components in body frame

Multiple Model Adaptive Rank Estimation for Integrated Navigation During Mars Entry

“…Based on the conclusions of the past research, three radio beacons are adopted in this paper. The inertial positions of three surface beacons are listed in Table 4 (Lévesque and de Lafontaine, 2007). The radio beacon/IMU integrated navigation filter parameters are shown in Table 5 (Li et al, 2014).…”

“…The physical parameters of the Mars entry vehicle used in this simulation are set as follows: B* = 0·016 m 2 /kg, L/D* = 0·156 (Lévesque and de Lafontaine, 2007). Furthermore, the number of radio beacons used for the navigation filter has been analysed by Lévesque and de Lafontaine (2007) and Pastor et al (2000).…”

“…Mars exploration missions play an important role in future deep space exploration activities, and the number of countries and international organisations, which have begun to focus planetary exploration activities on Mars is increasing. Several future international space missions have as an objective the return of Mars surface samples to the Earth (Lévesque and de Lafontaine, 2007). There are many key scientific goals for Mars explorations in order to deepen the understanding of the solar system formation process and the origin of life, such as the search for water and characterisation of aqueous processes on Mars, the study of mineralogy and weathering of the Martian surface, and the search for preserved biosignatures in Martian rocks (Burkhart et al, 2005;Li et al, 2014).…”

Mars Atmospheric Entry Integrated Navigation with Partial Intermittent Measurements

“…It is difficult to achieve this target if the only available measurement sensor is the on-board default inertial measurement unit (IMU) to provide measurement information for the navigation, guidance, and control system during Mars atmospheric entry phase [8,9]. An innovative integrated navigation scheme during Mars atmospheric entry was proposed, which is adding the range measurements between the vehicle and the surface beacons or orbiters by using the UHF radio communication [10,11]. The key technology of the above navigation scheme is that the UHF radio communication is not blocked by the plasma sheath around the vehicle.…”

“…National Aeronautics and Space Administration (NASA) develops an advanced Mars Network's Electra UHF transceiver, which is a prototype, embedded, real-time navigation system and can provide radio communication information between the vehicle and an orbiter or a surface beacon [10,12]. Levesque and de Lafontaine researched four integrated navigation scenarios and their observability based on radio ranging by using the unscented Kalman filter during the Mars atmospheric entry [11]. Li et al did a lot of works based on a six-dimension dynamic model by using radio communication under the IMU/beacon integrated navigation schemes [9,13,14].…”