Performance Improvements for Using Haptic Effects

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With our last post showing the haptic feedback test graphs for our Precision Haptic™ range, we can take a look at the performance enhancements achieved through these techniques.

For a full discussion of the advantages of haptics, you may be interested in checking out these guides on our website:

Haptic Feedback Overview

Haptic Feedback and Vibration Alerting Integration Guide

Again, we’re going to use the 305-000 haptic vibration motor (since depreciated) as our reference.

Time Reductions

See the table below for a comparison between the Step Response results and the Overdrive Step Response. Remember the Overdrive Step Response test uses haptic feedback drive techniques to improve the performance, in an attempt to give a ‘crisper’ user experience.

Parameter	Basic Effect	Haptic Feedback Effect
Typical Rise Time to 90%	140 ms	75 ms
Typical Stop / Active Brake Time	68 ms	24 ms
Total Effect Time	208 ms	99 ms

So by using haptic drive techniques, we can repeat our effect just over twice as many times in a given timeframe.

Power Consumption

So all this improved performance must come at a price, right? Surely it consumes more power?

Well, we can use the graphs to calculate the power consumption. Note that due to the sensitive nature of the current measurement, we will have to use approximations in the reading. You are encouraged to use your values and draw your conclusions if you wish!

We’re going to use an average value for the current consumption for each section of the effect, using the formula:

$$P=IV$$

Parameter	Basic Effect	Haptic Feedback Effect
Typical Rise Time to 90%	140 ms @ 85 mA	75 ms @ 120 mA
Typical Stop / Active Brake Time	68 ms @ 0 mA	24 ms @ 125 mA
Voltage Applied	1.3 V	1.7 V
Total Power Consumption	15.47 mW	20.4 mW

We can see that there is indeed a small increase in power consumption of 5 mW. This will differ depending upon the effect and the extent that the haptic effects are used within it. For example, the difference will be almost negligible if the effect has a long sustained period at its full vibration amplitude.

The example above can be considered as the worst-case scenario for the difference in power consumption due to the motor being driven at the Maximum Operating Voltage.

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