用力不断运动？

Question

单击向上箭头后，我如何才能使它保持运动状态？如果再次单击向上箭头，它应该会获得动力。我相信这应该发生在 FixedUpdate 中。当开枪时，“Fire1”的 if 语句会发生这种情况，但我需要对象本身保持运动状态。

float hInputValue;
float vInputValue;
float angle;
float RotationSpeed;
public GameObject target;
public GameObject circlePrefab;

void Start()
{
   angle = 0f;
   RotationSpeed = -2.5f;
}

void Update()
{
hInputValue = Input.GetAxis("Horizontal");
vInputValue = Input.GetAxis("Vertical");
float zRotValue = hInputValue * RotationSpeed;
angle += zRotValue;

   if (Input.GetButtonDown("Fire1"))
   {
      Vector3 circlePosition = transform.position + new Vector3(0f, 0.75f);
      Quaternion circleRotation = new Quaternion();
      GameObject CircleObject = Instantiate(CirclePrefab, circlePosition, circleRotation);
      circleMover mover = circleObject.GetComponent<circleMover>();
      Vector3 circleForce = new Vector3(0f, 0.04f, 0f);
      mover.ApplyForce(circleForce);
   }
}

private void FixedUpdate()
{
   float y = transform.position.y;
   y += vInputValue;
   Quaternion rotation = Quaternion.Euler(0f, 0f, angle);
   transform.rotation = rotation;
   transform.position = new Vector3(transform.position.x, y);

   Vector3 targetVector = new Vector3(0f, 4f);
   targetVector = rotation * targetVector;
   target.transform.position = targetVector;
   CirclePrefab.transform.position = targetVector;
}

我在 FixedUpdate 中尝试了 applyForce，但没有任何反应。