CN-114777809-B - Monocular vision inertial odometer virtual initialization method based on speed input

CN114777809BCN 114777809 BCN114777809 BCN 114777809BCN-114777809-B

Abstract

The invention discloses a monocular visual inertial odometer virtual initialization method based on speed input, which is a process aiming at the monocular visual inertial odometer virtual initialization, and can complete the visual inertial odometer initialization solving process of any carrier under different motion states by a monocular visual inertial odometer algorithm only by inputting speed parameters of an initial motion state in a computer, thereby realizing the navigation positioning function of the odometer algorithm. The invention can recover the initial value of the system in the degradation motion state which can not finish the initialization solution.

Inventors

ZENG QINGHUA
JIN ZIQI
ZHANG YIZHOU
HONG CHENG
LUO YIXUE
Li yineng

Assignees

南京航空航天大学
南京航空航天大学

Dates

Publication Date: 20260421
Application Date: 20220317
Priority Date: 20220317

Claims (4)

1. The monocular vision inertial odometer virtual initialization method based on the speed input is characterized by comprising the following steps of: Step 1, setting a simulation carrier, namely adaptively setting a track and a landmark point position of a virtual initialization process of a monocular vision inertial odometer by inputting a speed parameter at an initial moment in an actual movement process of the actual carrier, and setting a configuration parameter file of the virtual initialization process and a noise parameter of an inertial sensor; Step 2, generating virtual initialization simulation data in the step 1 in simulation software, and corresponding visual key frames in virtual initialization to visual key frames in actual motion according to time sequence, and corresponding inertial sensor data in virtual initialization to inertial sensor data in actual motion; And 3, starting a monocular vision inertial mileage calculation method, running the virtual initialization simulation data generated in the step 2 in a set virtual initialization time period to obtain a state quantity initial value of the simulation carrier, and finishing the butt joint of the state quantity of the simulation carrier and the state quantity of the actual carrier at the moment of finishing the virtual initialization, thereby finishing the virtual initialization of the monocular vision inertial mileage meter.
2. The method for virtual initialization of a monocular vision inertial odometer based on speed input of claim 1, wherein the virtual initialization process trajectory generated in step 1 satisfies two rules: Rule 1, the initial speed and attitude angle values of the simulated carrier in the process track are continuous values; rule 2 the initial velocity of the simulated carrier of the process trajectory and the first derivative value of the simulated carrier attitude angle with respect to time are both continuous values.
3. The method for initializing the virtual device of the monocular visual speedometer based on the speed input according to claim 1, wherein the adaptively setting the virtual device of the monocular visual speedometer in step 1 comprises the following steps: Step 1.1, initializing and exciting by using sine and cosine motions on three axes to form sine and cosine tracks, wherein the three axes are a north axis y pointing to the north and north, an east axis x pointing to the east and an sky axis z, and the expressions of the position p 1 (t), the speed v 1 (t) and the acceleration a 1 (t) of the simulation carrier during the sine and cosine motions are as follows: Wherein t represents time variable, A x 、A y 、A z represents amplitude of triaxial sine and cosine motion track, K is angular velocity multiple of the motion of the radial axis, t 1 represents preset time consumption of sinusoidal motion, pi (·) is proportional mapping relation ,A x ＝A x0 ·π(V 0 ),A y ＝A y0 ·π(V 0 ),A z ＝A z0 ·π(V 0 ),A x0 ,A y0 and A z0 both represent dimensionless values, wherein V 0 represents a model value of speed at initial moment in actual motion process of the carrier, namely motion instantaneous speed at current moment of the actual carrier after virtual initialization calculation is completed; the road mark points in the sine and cosine tracks are arranged in the visual field range of the track running process; Step 1.2, simulating the carrier to perform a quasi-flat-throwing motion after finishing the sine and cosine motion, so that the speed of the simulated carrier at the end of the quasi-flat-throwing motion is the same as the initial speed in the actual motion process of the actual carrier, and the expressions of the position p 2 (t), the speed v 2 (t) and the acceleration a 2 (t) of the carrier in the quasi-flat-throwing motion process are as follows: Where t 2 represents the preset time consumption of the quasi-level-throw motion, V y 、V z represents the velocity components in the y-axis and z-axis directions, respectively, and the component V y 、V z satisfies the following relationship: the road mark points in the horizontal projectile motion process are arranged in the visual field range of the horizontal projectile track running process.
4. The virtual initialization method of the monocular vision inertial odometer based on speed input according to claim 3, wherein the initial value of the state quantity of the analog carrier is obtained after the simulation data is run in the step 3, the process is performed with two state butt joints, the first state butt joint of the analog carrier at the moment of ending the sine and cosine motion and the moment of starting the quasi-panning motion is performed with the second state butt joint of the analog carrier at the moment of ending the quasi-panning motion and the state butt joint of the actual carrier in the actual motion at the moment of ending the virtual initialization, a sliding window is set for each butt joint process, k frame key frames are shared in one sliding window, and the positions, the postures and the speeds of the i frame key frames in the sliding window are respectively recorded as ps i 、Rs i 、vs i when the butt joint is performed for a certain time, wherein i=1, 2. Rs comp represents attitude angle compensation, and the expression is as follows: Where δ k denotes the value of the yaw angle in the speed direction of the kth frame in the sliding window.

Description

Monocular vision inertial odometer virtual initialization method based on speed input Technical Field The invention belongs to the technical field of positioning. Background The monocular vision inertial system has become popular in the field of autonomous navigation research due to the characteristics of simple structure, small occupied space, rich information acquisition and the like. Monocular vision inertial odometer is widely used as a mature navigation means in fields such as unmanned vehicles and unmanned aerial vehicle driving, logistics transportation, search and rescue, infrastructure inspection and the like. But in general, the visual mileage calculation method has a problem that it is difficult to complete the initialization process in the degraded motion state. Disclosure of Invention The invention aims to solve the problems in the prior art, and provides a monocular vision inertial odometer virtual initialization method based on speed input. The invention provides a monocular vision inertial odometer virtual initialization method based on speed input, which comprises the following steps: step 1, setting a simulation carrier, adaptively setting a track and a landmark point position of a virtual initialization process of a monocular vision inertial odometer, and setting a configuration parameter file of the virtual initialization process and noise parameters of an inertial sensor; step 2, generating virtual initialization simulation data in the step 1 in simulation software; And 3, running the virtual initialization simulation data generated in the step2 in a set virtual initialization time period to obtain a state quantity initial value of the simulation carrier, and finishing the butt joint of the state quantity of the simulation carrier and the state quantity of the actual carrier at the virtual initialization ending time so as to finish the virtual initialization of the monocular vision inertial odometer. Further, the virtual initialization process track generated in the step 1 satisfies the following two rules: Rule 1, the initial speed and attitude angle values of the simulated carrier in the process track are continuous values; rule 2 the initial velocity of the simulated carrier of the process trajectory and the first derivative value of the simulated carrier attitude angle with respect to time are both continuous values. Further, the adaptively setting the track and the landmark point position of the virtual initialization process of the monocular vision inertial odometer in the step 1 specifically comprises the following steps: Step 1.1, initializing and exciting by using sine and cosine motions on three axes to form sine and cosine tracks, wherein the three axes are a north axis y pointing to the north and north, an east axis x pointing to the east and an sky axis z, and the expressions of the position p 1 (t), the speed v 1 (t) and the acceleration a 1 (t) of the simulation carrier during the sine and cosine motions are as follows: Wherein t represents time variable, A x、Ay、Az represents amplitude of triaxial sine and cosine motion track, K is angular velocity multiple of the motion of the radial axis, t 1 represents preset time consumption of sinusoidal motion, pi (·) is proportional mapping relation ,Ax＝Ax0·π(V0),Ay＝Ay0·π(V0),Az＝Az0·π(V0),Ax0,Ay0 and A z0 both represent dimensionless values, wherein V 0 represents a model value of speed at initial moment in actual motion process of the carrier, namely motion instantaneous speed at current moment of the actual carrier after virtual initialization calculation is completed; the road mark points in the sine and cosine tracks are arranged in the visual field range of the track running process; Step 1.2, simulating the carrier to perform a quasi-flat-throwing motion after finishing the sine and cosine motion, so that the speed of the simulated carrier at the end of the quasi-flat-throwing motion is the same as the initial speed in the actual motion process of the actual carrier, and the expressions of the position p 2 (t), the speed v 2 (t) and the acceleration a 2 (t) of the carrier in the quasi-flat-throwing motion process are as follows: Where t 2 represents the preset time consumption of the quasi-level-throw motion, V y、Vz represents the velocity components in the y-axis and z-axis directions, respectively, and the component V y、Vz satisfies the following relationship: the road mark points in the horizontal projectile motion process are arranged in the visual field range of the horizontal projectile track running process. Furthermore, the initial value of the state quantity of the simulation carrier is obtained after the simulation data are operated in the step 3, the process is carried out for two times of state butt joint, wherein the first time is the state butt joint of the simulation carrier when the sine and cosine motion is finished and the quasi-flat projectile motion is started, the second time is the state butt joint of th