The SMART Controller


The SMART System is the patented term given to the control of the picking rod arms, of the shaker active head. The head is active in the sense that it moves sideways independently to the tractor unit (MAV), to compensate for the position of the vine and superstructure.

SMART_contrHow the SMART System achieves this is quite complex, and yet the four main parameters that control the shaker arms are set individually by the driver simply altering each one as he or she seems fit.

And this is where things can get out of step.

Having a logical and engineering mindset helps a driver to match their input requests to the controller, with what he or she is attempting to do.

Good practice requires starting ground speed of 4.0-4.5km/hr. This is particularly important at the beginning of the season, when it usually takes a couple of days for drivers to get into the swing, and re-acquaint themselves with the vibrations and noises of the harvester unit.

Lets make a few assumptions here, noting that they are based on my experience (in the Waipara Valley in Canterbury, the Awatere Valley in Marlborough and the Bannockburn-Bendigo-Lowburn-Alexandra-Clyde regions of Central Otago, and around Yea and Alexandra in the Yarra Valley, Melbourne).

  • Red varieties tend to be on vines with smaller canopies, picked mostly when the canopy is starting to shut down, or as in some instances non-existent, hence low MOG levels. Petioles are always an issue.
  • White varieties tend to be on vines with larger canopies, are often the heavier crops, with quite weighty MOG. Petioles are an issue with late harvests.
  • Varieties picked for champagne are usually early picks, resulting in slower ground speeds, higher settings and DECREASED shaker arm centres.

I’ve harvested Sauvignon where the crop is so heavy that a maximum ground speed was 3.5km/hr, simply because the high quantity of fruit was over-running the mechanical processes. In another scenario, a 350m Scott Henry trained row yielded over 2 tonne of fruit, spilling over the sides of the bins.  I have also harvested Pinot so late in the season, there was no point in using the main or upper fans, relying completely on The Finishing Department to remove the petioles.

SMART_whitePinch settings (left) show an arbitrary value but notice that as the season progresses, the tendency is for this figure to reduce, as the vines begin to drop their canopy. The adverse effect then is an increase in MOG.

Amplitude shown is set to maximum (or near to it) at the beginning of the season, and reduces much as the season progresses. I have run this setting as low as 45% for late harvest varieties.

Acceleration is of more use at the beginning of the season, as it is usually more difficult at this time to remove fruit from the vine. After this early period, acceleration is generally not a requirement.

Frequency (or cycles) is set to the upper band in the early season (500-525), and rapidly drops as the season progresses. The bulk of the harvesting season should be able to be done around 480 to 495 cycles.

But it is not as simple as this. What is most important is the relationship between amplitude and frequency. Whilst it is mechanically possible to set the machine to an amplitude of 120% (20% longer than its standard 150mm stroke) – at that increased distance it would be excessive to have the frequency around 500 or higher. High cycling the machine picking arms over a long distance would be akin to driving to work in first gear, but at high revs so as to get there.

SMART_rangeThe relationship should be low amplitude – high frequency, and vice versa.

The relationship between frequency and acceleration is important too. For a given set of cycles, when you accelerate any part of that cycle, another part of that cycle has to slow down, or pause. For example, if you add acceleration to the cycle, because the shaker arms are still cycling at the same measure PER MINUTE, then between each stroke there is a pause. This is why acceleration is sometimes called ‘punch.’ Combine an increase in acceleration with a pinch setting that is too wide, the shaker arms will slap or punch the vines to oblivion.

The more vigorous the canopy agitation, then more MOG is present – which has to be dealt with by the other processes. Consequently, ALL settings work together, to give the finished sample. At times, particularly late harvest, one can’t avoid removing the remaining canopy from the vines. This increases the role of the fans and The Finishing Department, and the operator needs to constantly watch all areas and make continual changes to make sure a good sample is provided.

Speed is directly proportional to the frequency. The chart below shows this. At a speed of 4km//hr, the harvesting unit is travelling along the vine, at 1.11 metres per second. If the frequency is set at 490 beats per minute, then for every metre of travel the vines are shaken 7.4 times.

SpeedvsCyclesAt the same number of cycles, doubling the speed halves the frequency for EVERY METRE of vine.

An experienced operator will begin harvesting at 4.0-4.5km/hr. As the machine warms, as the oils come up to temperature, as the shaker arms settle into their natural harmonic rhythm, so its effectiveness in picking fruit increases. This results in the need to reduce certain settings (particularly amplitude and frequency). Alternatively, it also allows a corresponding increase in ground speed.

An increase in ground speed with no change in frequency correlates to a significant decrease in the cycles per metre (Cps/m). The decrease is shown as a percentage in the above table (from the original starting speed). Where the interests of the winemaker/vineyard owner are being looked after, an operator will start at a low speed and work upwards towards 5.0-5.5km/hr, whilst at the same time REDUCING his shaker arm settings. It is about matching the machine’s settings with the environmental conditions.

An inexperienced or lazy operator will start at the speed he or she is comfortable at, set relatively high shaker parameters, and maintain this for the rest of the day, thinking he or she is performing well based on the fruit being removed from the vines. This is needless, as making the machine work harder than necessary increases its wear, and potentially damages vines and canes.

Racing along at 6-8km/hr can be fun, but things go wrong much more quickly than is sometimes expected. At this speed in heavy crops, it will take only a few minutes to fill the bins, and that is all it takes to collect a whole heap of petioles or other undesirables.

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Post settings are much simpler to understand when you understand how the shaker arms work. But there are two schools of thought, and the decision of which theory to use, is left squarely in the hands of the winemaker / vineyard owner – without fully understanding the disadvantages of either of them.

The vineyard owner wants to make sure all the fruit is removed from around the posts. This requires more vigorous parameters around the posts. This can dramatically increase problems, especially if the settings are not chosen correctly, or are too severe. That is the disadvantage.

The winemaker sometimes isn’t too concerned whether the fruit is fully picked around posts. Winemakers typically only pay for the fruit by weight at the winery. They may also understand that it is often difficult to remove all fruit around the post, and may be happy that no attempt is made to do so.

SMART_postThe harvesting parameters shown left (top line) are typically for a early season harvesting. The second line shows a typical matching setting (which correlate to the main harvesting parameters shown), and reflects the winemaker’s stance.

Here the pinch increases to 90mm, about the size of standard post, although it could be anywhere between 80 to 140mm. This assists with reducing the wear on the nylon shaker arms. By opening up when a post is detected, it allows a post to pass freely.

Now picture the arms, with a post separating and dividing them. Physically, the stroke (amplitude) is restricted, so a REDUCTION in this setting should be the need. The reduction needs to be carefully considered, as there is some movement of the arms around the post.

Accelerating at this time could be considered only because we have DECREASED the amplitude, however  the restrictive nature of the post doesn’t necessarily limit the effectiveness of a small amount of acceleration. I rarely choose this option.

Frequency is typically increased here, sometimes up to 540, to increase the shaking rhythm to offset the other limitations.

But some believe the solution is to INCREASE the amplitude, because the post is restricting the movement (amplitude) and the effectiveness of the action. I find this somewhat counter-productive as nothing can overcome the fact that the post is physically restricting the shaker arms. Violently shaking the post rarely removes all 100% of fruit, but may break rotten, soft, knotty and wet posts. It also causes significant wearing of  the shaker arm mounting axles. The argument that the arms ‘wrap around’ the back of the post I find is somewhat flawed, in the sense that it would require the perfect setting – pinch (to give the flexibility), amplitude (balance between ‘wrap-around effect’ and post damage), and the cycles.

It takes some years in mastering the settings of the SMART System controller, even longer when your experience is built on a lot more variables – such as smaller and more variable vineyard locations, mixed in with different varieties.

There is most definitely a sweet-spot where a group of settings matched with the correct ground speed will perform an almost perfect result. Sometimes this is easily found, other times not so. But the over-riding cause when the machine  is struggling to harvest grapes with vines reluctant to let go their fruit – is an inappropriate ground speed.

An operator struggling to meet the desired result, first needs to slow down.

Then the operator must take a considered approach to each and every individual process the machine is undertaking. But here’s a little more on the Smart Controller parameters.

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One response to “The SMART Controller

  1. Pingback: The Picking Head Shaker Bars | Musings of a Know-It-All

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