function [ tf, motion ] = calc_maneuver( ps,pe,pi )
%GET_MOTION Calculate motion time and acceleration
%   此处显示详细说明
ti = 0; % 无用的申明
pd = [0;0;0]; % 无用的申明

global BM_SHUTDOWN_SPEED IM_RANGE IM_SHUTDOWN_SPEED MOTION_SPEED
vs = get_aiming_vel(ps,pe,BM_SHUTDOWN_SPEED);
state = [ps;vs];
[pc_t,vc_t,tt] = get_free_flight_ball(state, 3.6e3);

[ti,pd] = get_interception_point(pc_t, tt, pi,IM_RANGE);
[ pf, vf, tf ] = get_interception_params(pi, pd, IM_SHUTDOWN_SPEED, ti);

i = find(tt == tf);
pc = pc_t(i,:)';
vc = vc_t(i,:)';

view_direction = (pc - pf);
motion_direction = cross(cross(vc, vf), -view_direction);
motion = MOTION_SPEED * motion_direction / norm(motion_direction);
end