Disinfection robots

Patent metadata

Field	Value
Publication number	US-2023126179-A1
Application number	US-202217969850-A
Country	US
Kind code	A1
Filing date	Oct 20, 2022
Priority date	Oct 21, 2021
Publication date	Apr 27, 2023
Grant date	—

Abstract

A UV based surface disinfection system that consists of the UV light source, a robot arm, and an omni directional mobile base. The mobile robot can be programmed autonomously and be able to bring the UV light source to the centimeters away from surfaces to achieve effective and efficient surface disinfection. The mobile robot can navigate autonomously in a complicated environment to perform disinfection operation in a large area.

First claim

1 . A disinfection robot comprising:
a mobile base with omni-directional wheels; a universally positionable manipulator with an end effector (E.E.); a UV lamp module attached to the end effector of the manipulator that includes a UV disinfection lamp and a ranging module using sensors to detect the distance of the lamp from a surface to be disinfected; and an electronic control system for planning a path for the UV lamp to be moved over the surface based on information from the sensors by controlling the directional wheels of the base and the movement of the manipulator.

2 . The disinfection robot according to claim 1 wherein the ranging module includes a multi-line laser scanner and a 360 degrees camera.

3 . The disinfection robot according to claim 2 wherein the ranging module is a LiDAR system.

4 . The disinfection robot according to claim 1 further including a remote processor with a transceiver and a transceiver connected to the electronic control circuit so the remote processor and electronic control circuit can communicate over a transmission link so that a user can control the robot remotely.

5 . The disinfection robot according to claim 4 wherein the remote processor and the electronic control circuit communicate over a WiFi transmission link.

6 . The disinfection robot according to claim 1 wherein the universally positionable manipulator has 3 rotational joints, which are located in three XYZ joint frames, and the mobile base is located in a separate XYZ frame.

7 . The disinfection robot according to claim 1 wherein the electronic control system acquires in task space from the sensors the velocity, acceleration, position and time according to the known initial and end points, and generates a plan for a trajectory to control the end-effector so it follows this trajectory.

8 . The disinfection robot according to claim 7 wherein the trajectory is divided into three sections: third-order, fifth-order and third-order trajectories; and after performing the third-order, fifth-order and third-order trajectories in the planner, the pose of each point in task space is transformed into joint space to control the robot's joint through an inverse kinematics and a Jacobian matrix so that commands can be published to control the joints based on the position and velocity, where the velocity and position correspond to a specific time.

9 . The disinfection robot according to claim 1 wherein the electronic control system contains a feedforward part and a feedback part and a controller for the manipulator,
wherein a first part (the feedforward) is acquired through a Dynamics model to compute torque in the controller and the second part (feedback) is the position and velocity,
wherein based on the position and velocity error, the position loop and velocity loop are constructed,
wherein the feedforward of torque is combined with the position loop and velocity loop to calculate the decoupling output, the controller output is a torque whose value satisfies the requirement of the entire robot system in order to realize a target, including mutual influence between each joint; and
wherein the torque output is provided to a driver for the manipulator, and the driver generates current to make manipulator motors operate according to the corresponding torque.

10 . The disinfection robot according to claim 1 wherein the electronic control system plans a path according to an object perceptive local planner method comprising the steps of:
segmenting X(t) segments from a real-time point cloud;
segmenting X ref (s) segments from a global map as the end effector's desired path;
using the selected segments X(t) with a point cloud sliced Wasserstein based perceptive motion local planner to map the UV desired path compared to the actual UV path;
updating the comparison; and
updating the speed profile of the end effector along the geodesics path, whereby the optimal transport path from X(t) to X ref (s) is established.

11 . The disinfection robot according to claim 10 wherein the comparisons is updated at a rate of 10 Hz and the speed profile is updated at a rate of 50 Hz.

12 . The disinfection robot according to claim 1 further including a time-of-flight (ToF) camera attached to the UV light module at the end-effector and a Light Detection and Ranging (LiDAR) device on the robot base, and wherein the method of planning the path comprises the steps of:
receiving a present image, I(t), a present point cloud X(t) and camera_intrinsics.yaml & camera_tof_If.launch signals from the robot at a present point cloud segmentation processor;
producing at the present point cloud segmentation processor a visual cone in the local frame and X seg (t), which is delivered to a sliced perceptive object tracker;
receiving UV_desired.txt, Map.ply and p_num(s) at a.reference point cloud generator, which in turn generates X′ seg (s), which is applied to the sliced perceptive object tracker along with an EE State (velocity or acceleration) and EE constraints, wherein the EE constraints come from joint dynamic constraints and environmental information (e.g., friction) after passing through a dynamics module;
causing the sliced perceptive object tracker to engage in trajectory planning with dynamic constraints on a geodesics path and Wasserstein barycentre as intersections from X to X′, wherein the tracker produces as an output the point cloud registration (based on sliced Wasserstein distance);
passing the point cloud registration to a point cloud sliced Wasserstein based perceptive motion local planner, wherein the planner has its output tf: from/UV to/UV desired directed to the reference point cloud generator as an input along with X′ seg (s) and LiDAR_FoV.yami;
applying a second output of the planner to a calculation block which engages in e_calculation (known/map to/UV), which provides the input P_num(s) to the reference point cloud generator; and
applying an output p(T) from the tracker to a kinematics unit to create q(t), which is directed to the robot, and which in turn provides the present image and present point cloud applied to the present point cloud segmentation unit, whereby global localization is used as an initial condition, then it mainly compares reference point cloud and present point cloud in the end effector frame (E.E.F.) of the mobile manipulator based on Wasserstein distance, and then outputs rigid transformation between them at a low frequency and desired velocity along the optimal path of the end effector at a high frequency.

13 . The disinfection robot according to claim 1 for conducting a disinfection task with respect to a movable object, further including a 3D camera on the end effector of the robot, and
wherein the electronic control system includes a disinfection motion planning module with a Local Reference Frame (R_(L.R.F)) attached to the movable object that carries out the steps of”
obtaining a reference point cloud in advance;
collecting a target point cloud with the 3D camera;
utilizing a vector space with a point cloud registration algorithm to output a transformation matrix in the vector space based on the reference point cloud and the target point cloud, wherein the transformation matrix is acquired for converting from the reference point cloud to the target point cloud;
transferring the original motion planning that is attached to the movable object to the target object according to the output transformation matrix; and
causing the robot end effector to follow a given path and trajectory to finish the disinfection of the movable object without being required to perform additional motion planning for the entire path and traje

Assignees

• Versitech Ltd

Inventors

• Xi Ning
• Ma Ye
• Wang Siyu
• Wang Qingyang
• Ye Jiajie
• Kwok Chun
• Bi Sheng

Classifications

• A61L2103/75

  Room floors or walls · CPC title

• G05D2107/60

  Open buildings, e.g. offices, hospitals, shopping areas or universities · CPC title

• G05D1/242

  Means based on the reflection of waves generated by the vehicle (using passive navigation aids external to the vehicle G05D1/244; using signals provided by artificial sources external to the vehicle G05D1/247) · CPC title

• G05D2111/17

  Coherent light, e.g. laser signals · CPC title

• G05D2111/14

  Non-visible signals, e.g. IR or UV signals · CPC title