Article 8: Design of multi-functional intelligent trunk following control system | undergraduate graduation project - [reply and Q & a record of design completion]

ask 1: Multifunctional intelligent following luggage compartment , What if the battery runs out ？ What are the countermeasures ?
answer : The smart luggage has been designed with no electricity at the beginning . The main design point is the design of the power wheel , The power wheel is designed to be liftable , In auto follow mode, the power wheel descends , Drive the trunk to travel ; If the luggage compartment is dead , The power wheel will rise automatically , The suitcase is like an ordinary trolley case , Walking with the box .

ask 2: What is the process of creating the mathematical model of the luggage compartment following the movement ?
answer : The motion model of the luggage compartment is actually a two-dimensional plane coordinate system , Take a point in the plane of the luggage compartment O Origin , Set up a rectangular coordinate system O-xy, With a The position of the suitcase at two adjacent times with a short time interval is the research object . Trunk rotation The bending radius is set to R, The center distance between the two driving wheels of the luggage compartment is set to L,υL and υR They are the left side of the trunk 、 Speed of the right drive wheel ,θ1 It is the turning angle of the trunk at two adjacent moments ,θ2 It is the suitcase that flies at two adjacent times The amount of angular change ,θ3 Is the auxiliary angle , And θ1 identical . Set the speed of the trunk to υ, Angular velocity is ω. From the geometric relation in the figure, we can get θ1=θ2=θ3 The formula 2.5 Note that the adjacent time interval is Δt, because Δt Very small , Its own attitude and heading angle change θ2 Very small , so The approximate formula can be obtained ： 𝜃3 ≈ sin 𝜃3 = 𝑑 𝐿 = (𝑣𝑅−𝑣𝐿 )∆𝑡 𝐿 The formula 2.6 The angular velocity of the luggage compartment is ： 𝜔 = 𝜃3 ∆𝑡 = 𝑣𝑅−𝑣𝐿 𝐿 The formula 2.7 The forward speed of the luggage compartment is the average speed of the left and right driving wheels ： 𝑣 = 𝑣𝑅+𝑣𝐿 2 The formula 2.8 The turning radius of the luggage compartment can be expressed as ： 𝑅 = 𝑣 𝜔 = 𝐿(𝑣𝑅+𝑣𝐿) 2(𝑣𝑅−𝑣𝐿) The formula 2.9 The trunk movement control is mainly to control the speed of the left and right driving wheels of the trunk to realize the control of the front of the trunk Advance speed 、 Control of steering angular speed, turning radius and other parameters , So we use three-dimensional vector 𝐺 = [𝑣𝜔𝑅] 𝑇 As a line The control vector of the suitcase .

ask 3:Uwb Relationship with the base station
answer :Uwb It is a positioning chip or positioning module , The base station and the tag are used to receive and transmit location information . Base station and tag usage UWB Made of modules .

ask 4: How to achieve automatic following ?
answer : First, follow automatically , Based on positioning technology , By getting the user's position coordinates , Calculate the relative coordinates of the user relative to the luggage compartment , Through the motion model of the luggage compartment , Control the differential movement of the power wheel to control the direction of the box , The travel speed of the luggage compartment is controlled according to the distance between the luggage compartment and the user , So as to achieve the effect of automatic following .