     func updateForceToTarget() {
         let isIncrease = (forceValue < targetForceValue)
         if isIncrease {
-            forceValue = min(forceValue + interpolationStep, targetForceValue)
+            forceValue = min(forceValue + interpolationSpeed, targetForceValue)
             if forceValue >= targetForceValue {
                 displayLink?.invalidate()
             }
         }
         else {
-            forceValue = max(forceValue - interpolationStep*2, targetForceValue)
+            forceValue = max(forceValue - interpolationSpeed*2, targetForceValue)
             if forceValue <= targetForceValue {
                 forceValue = 0.0
                 displayLink?.invalidate()

        if forceValue < 0.98 {
            targetForceValue = 0.0
            currentThresholdIndex = 0
        }
    }
    
    private func handleTouch(touch: UITouch)
    {
        if #available(iOS 9.0, *) {
            self.cancelTouches()
            let forcePercentage = touch.force/touch.maximumPossibleForce
            targetForceValue = Double(forcePercentage)
        }
    }
    

        if let touch = touches.first where isTouchValid(touch)
        {
            if #available(iOS 9.0, *) {
                if traitCollection?.forceTouchCapability != UIForceTouchCapability.Available || TARGET_OS_SIMULATOR == 1 {
                    self.performSelector("delayedFirstTouch:", withObject: touch, afterDelay: 0.25)
                }
            }
