Help with send_goal velocity control

edit

The code below was given in a separate question asked on this website, and it is used to send destination waypoints to a Husky robot in Gazebo. It works, but I am curious about part of its function. The Husky travels to the desired waypoints, but it doesn't seem possible to customize the velocity of the robot while traveling to its desired point. In most of the code doing this, the send_goal function is used. Is there a way to look more closely at what is going on in this and customize some aspects? I want to keep the ability to travel to waypoints and be able to control the velocity of the Husky robot to speed it up at some points.

#! /usr/bin/env python3

import rospy
import actionlib
from move_base_msgs.msg import MoveBaseAction, MoveBaseResult, MoveBaseGoal

class MoveHusky(object):
  def __init__(self):
    self.client = actionlib.SimpleActionClient('/move_base', MoveBaseAction)
    self.client.wait_for_server()
    self.goal = MoveBaseGoal()

  def moveToDest(self, x, y):
    self.goal.target_pose.header.frame_id = "odom"
    self.goal.target_pose.pose.position.x = x
    self.goal.target_pose.pose.position.y = y
    self.goal.target_pose.pose.orientation.z = 0.7071
    self.goal.target_pose.pose.orientation.w = 0.7071
    rate = rospy.Rate(10)
    self.client.send_goal(self.goal)
    result = self.client.get_result()
    while result == None:
      result = self.client.get_result()
      status = self.client.get_state()
      rospy.loginfo("Status: {}".format(status))
      rospy.loginfo("Result: {}".format(result))
      rate.sleep()

if __name__ == "__main__":
  rospy.init_node("move_base_client")
  moveHusky = MoveHusky()

  while not rospy.is_shutdown():
    moveHusky.moveToDest(-4.0, 0.0)
    moveHusky.moveToDest(-4.0, -2.0)
    moveHusky.moveToDest(0.0, 0.0)