«Моментные самосвалы» и «Самосвалы TUM»

Прежде всего, важно установить разницу между «Моментным самосвалом» и «Самосвалом TUM».

«Моментный (текущий) самосвал» — это такой самосвал, который эксплуатируется и имеет результат своей работы в определенный момент во времени. В то время как «Самосвал (модели использования времени) TUM» — это количество часов работы самосвала за период, разделенное на количество часов для каждого самосвала в периоде на основе модели использования времени (TUM).

На практике, самосвалы не соблюдают модель использования времени (TUM) в каждый момент времени — самосвал либо доступен, либо недоступен, а не вместе. Возможно, что самосвал будет эксплуатироваться в момент времени в будущем (модель использования времени — это среднее значение за длительный период). Это наиболее правильный способ представления самосвалов на моментной основе и для краткосрочного планирования. Модель использования времени учитывает, но не содержит в явном виде частоту и продолжительность событий простоя (например, циклоны в сравнении с сломанным зубом ковша).

В Production Scheduler версий 21.2 и выше самосвалы TUM больше не используются, вместо них используется приблизительное значение моментных самосвалов. Instant Units (Моментные единицы) — это вычисляемое поле, представляющее количество введенных единиц, умноженное на PA, UPA, OE, UA и PF. Теоретически, моментные единицы — это точное количество самосвалов, которое, как ожидается, будет доступно для использования в любой момент времени в календарном плане.

Назначение самосвалов

В начале каждого периода Production Scheduler определяет точное количество самосвалов, которое, как ожидается, будет доступно для использования в любой момент в течение периода. Зная количество доступных самосвалов, их требуется назначить выполняющим операцию добычи агентам во время каждого установившегося положения. Решение о назначении самосвалов теперь выполняется механизмом оптимизации в Production Scheduler, а не пользователем.

Основной задачей оптимизации в Production Scheduler является максимальное увеличение суммы финансовых средств, получаемых в результате перемещения добытой породы, с учетом накладываемых календарным планом ограничений. Такое перемещение материалов приравнивается к определенной стоимости в долларах и отличается для разных перемещений. В большинстве случаев, более прибыльные перемещение включают отправку материала в дробилку. Чтобы отдать приоритет более прибыльным перемещениям, следует обеспечить максимальную производительность генерирующих их агентов, предоставив им достаточное количество самосвалов.

This process has been manual and involved users adjusting rates on a period by period basis. In APS 21.2, assigning trucks is automatic and works by prioritising Agents who generate movements with high revenue. As a simple example, if the highest revenue is for crusher feed movements, trucks will be prioritised to the Agents who are mining ore. The remaining trucks will then get assigned to Agents generating the next highest revenue movements. This process continues until either all of the available truck units have been assigned or if every Agent is operating at its maximum capacity. In many cases, lower priority Agents may not receive enough trucks causing them to fall short of their maximum operating capacity. When an Agent is under trucked, the Agents Productive Rate will automatically beadjusted to match the number of trucks assigned.

In summary, trucks are assigned to Agents based on how much money their movements are generating. If users wish to have full control and set the priority based on Agent, individual cash flows filtered by the individual Agents can be created. This setup can be useful when there is a duration where a particular Agent mining waste needs to be prioritised. The cash flow for that particular Agent can be increased so that its movements result in high revenue, bumping it up the priority list.

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Limiting Trucks

Despite the APS optimisation automatically assigning trucks to Agents, users can place some restrictions. These limits can either be placed on individual Agents or on Truck Assignment Rules. The option to enable this functionality is located in the Final Configuration Step in the Setup Tab.

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Agents

Limiting an Agent will enforce a hard constraint on the number of physical truck units the Agent can use during a single Steady State. In most cases, limiting the trucks for an Agent will cause the Agents rate to be reduced. The rate will be automatically adjusted to match the number of trucks specified—the image below highlights where this value can be set within the Calendar.

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Truck Rules

Similar to Agents, limiting trucks within a Truck Assignment group enforces a hard constraint on the number of physical trucks available to be used within the group. Limiting trucks here can be useful for splitting trucks of the same model into different fleet groups.

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Reporting Truck Usage

Both TUM trucks and Instantaneous trucks can be reported in APS; however, how each is reported is different.

Instantaneous Trucks

Reporting instantaneous trucks in traditional period-based reports simply doesn’t work due to the instantaneous time paradigm; however, there are several other places where the instantaneous trucks can be viewed and reported.

Steady States

Within the Steady States tab, trucking requirements for an Agent can be viewed at any instant in time. The field “Haulage.Instanatenous Trucks” reports how many trucks are currently assigned to the selected Agent.

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Truck Graphs

In the Final Configuration Step, there is an Instantaneous graph option. When enabled, users will see the number of trucks each Agent was using and how many trucks are being used overall.

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TUM Trucks

Reporting TUM trucks involves looking at consumed truck hours over the period. Users can find information on calculating truck hours at the following link PS Truck Hour Calculation .

Chrono Report

TUM trucks can be reported in a Chrono report by dividing the number of hours available per truck by the productive hours of that particular truck. The number of hours available per truck is available in the Calendar Data Source field list. Users can also find the total productive hours of a particular truck model Mining Data Source field list. A filter must be applied to return the productive hours of the required truck model. These fields and the calculation of truck hours is shown in the image below.

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Why can’t I report the number of trucks in a Pivot report?

You might think that you could divide the truck hours in each movement by the number of truck hours per unit in the schedule and sum that up in a pivot table. And you’d be right - but only if the sums are broken down into the scheduling periods as specified in the calendar - if not, it doesn’t work.

Truck Graphs

In the Final Configuration Step, there is a TUM truck graph option. When enabled, users will see the number of TUM trucks used over the period for each Agent and how many TUM trucks were used overall for the period.

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Calendar

In the Calendar, under each truck model, both the productive hours consumed and the amount of TUM trucks this equates to can be seen. For a selected Agent, it is also possible to view how many TUM trucks of each truck model the Agent consumed.

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The Fleet Use of Availability value represents the calculated Use of Availability of the fleet of trucks. This value is calculated without considering the [UA] input. The below example shows one way in which this value is calculated.

Hours per Unit = Period Duration * [PA] * [UPA] * [OE] * [PF]

Number of Trucks = Productive Hours / Hours per Unit

Fleet Use of Availability = Number of Trucks  / Number of units

Why do my truck numbers look so high/low? What can I do about it?

• Examine the animation, which displays the routes taken to ensure the correct paths are being used. If not, use Haul Infinity to ensure the correct routes are used. Take the time to ensure your haulage model is correct before starting to schedule.

• Use a pivot report to ensure that the right destinations are used for each material type. If not, alter the destination rules.

• If the numbers are too high, look to mine some material with shorter hauls.

• If the numbers are too low, there’s an opportunity to mine some material with longer hauls.

• Your last option, if you’ve tried the above, is to derate or shut down diggers. Often this cannot be avoided to meet short term ore requirements.

Is this schedule achievable with our truck fleet?

To determine whether the schedule is achievable with the truck fleet on-site, consider the Fleet Use Of Availability (UA), which is reported for each truck in the Calendar. Although many sites have a historical UA, this should not be an input (and is not when Dispatch mode is enabled). There is nothing wrong with varying the UA for the truck fleet each day, provided the objectives of the schedule are met. The reported fleet use of availability indicates how close to the edge the schedule is running. If the UA is at 100% fleet use of availability, then if a truck goes down, the schedule may not be achievable (it still may be if there’s an opportunity to catch up later). If it’s at 50%, half the expected trucks could be inoperable, and the schedule is still achievable.