private void leftComp(float a, int vel) {

        for (float i = 0; i < a; i++) {
            if (!this.touchRobotRotate()) {
                
                this.rotateRobot(-1);
                if (this.checkTouchBullet()) {
                    this.onHitByBullet();
                    return;
                }

                try {
                    Thread.sleep(vel);
                } catch (InterruptedException ex) {
                    Logger.getLogger(Robot.class.getName()).log(Level.SEVERE, null, ex);
                }
            } else {
                this.onTouchRobot();
            }
        }
    }