README.md

---
license: apache-2.0
pipeline_tag: reinforcement-learning
tags:
- Deep Reinforcement Learning
- Combinatorial Optimization
- Reinforcement Learning
- Vehicle Routing Problem
---

  ![](./images/GREEDRL-Logo-Original-640.png)


# ✊‍GreedRL

## 🏆Award


## Introduction

* **GENERAL**


* **HIGH-PERFORMANCE**
  
* **USER-FRIENDLY**


## Architecture design
The entire architecture is divided into three layers:

* **High-performance Env framework**

    The constraints and optimization objectives for the problems to be solved are defined in the Reinforcement Learning(RL) Environment(Env).
    Based on performance and ease of use considerations, the Env framework provides two implementations:one based on **pytorch** and one based on **CUDA C++**.
    To facilitate the definition of problems for developers, the framework abstracts multiple variables to represent the environment's state, which are automatically generated after being declared by the user. When defining constraints and optimization objectives, developers can directly refer to the declared variables.

    Currently, various VRP variants such as CVRP, VRPTW and PDPTW, as well as problems such as Batching, are supported.


* **Pluggable NN components**

    The framework provides certain neural network(NN) components, and developers can also implement custom neural network components.


* **High-performance NN operators**

    In order to achieve the ultimate performance, the framework implements some high-performance operators specifically for Combinatorial Optimization(CO) problems to replace pytorch operators, such as the Masked Addition Attention and Masked Softmax Sampling."

    ![](./images/GREEDRL-Framwork.png)

## Network design
The neural network adopts the Seq2Seq architecture commonly used in Natural Language Processing(NLP), with the Transformer used in the Encoding part and RNN used in the decoding part, as shown in the diagram below.

  ![](./images/GREEDRL-Network.png)

## Modeling examples


### Capacitated Vehicle Routing Problem (CVRP)
<details>
    <summary>CVRP</summary>

```python
from greedrl.feature import *
from greedrl.variable import *
from greedrl.function import *
from greedrl import Problem, Solution, Solver
from greedrl import runner

features = [continuous_feature('task_demand'),
            continuous_feature('worker_weight_limit'),
            continuous_feature('distance_matrix'),
            variable_feature('distance_this_to_task'),
            variable_feature('distance_task_to_end')]

variables = [task_demand_now('task_demand_now', feature='task_demand'),
             task_demand_now('task_demand_this', feature='task_demand', only_this=True),
             feature_variable('task_weight'),
             worker_variable('worker_weight_limit'),
             worker_used_resource('worker_used_weight', task_require='task_weight'),
             edge_variable('distance_last_to_this', feature='distance_matrix', last_to_this=True),
             edge_variable('distance_this_to_task', feature='distance_matrix', this_to_task=True),
             edge_variable('distance_task_to_end', feature='distance_matrix', task_to_end=True)]


class Constraint:

    def do_task(self):
        return self.task_demand_this

    def mask_task(self):
        # 已经完成的任务
        mask = self.task_demand_now <= 0
        # 车辆容量限制
        worker_weight_limit = self.worker_weight_limit - self.worker_used_weight
        mask |= self.task_demand_now * self.task_weight > worker_weight_limit[:, None]
        return mask

    def finished(self):
        return torch.all(self.task_demand_now <= 0, 1)


class Objective:

    def step_worker_end(self):
        return self.distance_last_to_this

    def step_task(self):
        return self.distance_last_to_this
```

</details>

### Pickup and Delivery Problem with Time Windows(PDPTW)
<details>
    <summary>PDPTW</summary>

```python
from greedrl.model import runner
from greedrl.feature import *
from greedrl.variable import *
from greedrl.function import *
from greedrl import Problem, Solution, Solver

features = [local_category('task_group'),
            global_category('task_priority', 2),
            variable_feature('distance_this_to_task'),
            variable_feature('distance_task_to_end')]

variables = [task_demand_now('task_demand_now', feature='task_demand'),
             task_demand_now('task_demand_this', feature='task_demand', only_this=True),
             feature_variable('task_weight'),
             feature_variable('task_group'),
             feature_variable('task_priority'),
             feature_variable('task_due_time2', feature='task_due_time'),
             task_variable('task_due_time'),
             task_variable('task_service_time'),
             task_variable('task_due_time_penalty'),
             worker_variable('worker_basic_cost'),
             worker_variable('worker_distance_cost'),
             worker_variable('worker_due_time'),
             worker_variable('worker_weight_limit'),
             worker_used_resource('worker_used_weight', task_require='task_weight'),
             worker_used_resource('worker_used_time', 'distance_matrix', 'task_service_time', 'task_ready_time',
                                  'worker_ready_time'),
             edge_variable('distance_last_to_this', feature='distance_matrix', last_to_this=True),
             edge_variable('distance_this_to_task', feature='distance_matrix', this_to_task=True),
             edge_variable('distance_task_to_end', feature='distance_matrix', task_to_end=True)]


class Constraint:

    def do_task(self):
        return self.task_demand_this

    def mask_worker_end(self):
        return task_group_split(self.task_group, self.task_demand_now <= 0)

    def mask_task(self):
        mask = self.task_demand_now <= 0
        mask |= task_group_priority(self.task_group, self.task_priority, mask)

        worker_used_time = self.worker_used_time[:, None] + self.distance_this_to_task
        mask |= (worker_used_time > self.task_due_time2) & (self.task_priority == 0)

        # 容量约束
        worker_weight_limit = self.worker_weight_limit - self.worker_used_weight
        mask |= self.task_demand_now * self.task_weight > worker_weight_limit[:, None]
        return mask

    def finished(self):
        return torch.all(self.task_demand_now <= 0, 1)


class Objective:

    def step_worker_start(self):
        return self.worker_basic_cost

    def step_worker_end(self):
        feasible = self.worker_used_time <= self.worker_due_time
        return self.distance_last_to_this * self.worker_distance_cost, feasible

    def step_task(self):
        worker_used_time = self.worker_used_time - self.task_service_time
        feasible = worker_used_time <= self.task_due_time
        feasible &= worker_used_time <= self.worker_due_time
        cost = self.distance_last_to_this * self.worker_distance_cost
        return torch.where(feasible, cost, cost + self.task_due_time_penalty), feasible
```

</details>


### VRP with Time Windows(VRPTW)
<details>
    <summary>VRPTW</summary>

```python
from greedrl import Problem, Solution, Solver
from greedrl.feature import *
from greedrl.variable import *
from greedrl.function import *
from greedrl.model import runner
from greedrl.myenv import VrptwEnv

features = [continuous_feature('worker_weight_limit'),
            continuous_feature('worker_ready_time'),
            continuous_feature('worker_due_time'),
            continuous_feature('worker_basic_cost'),
            continuous_feature('worker_distance_cost'),
            continuous_feature('task_demand'),
            continuous_feature('task_weight'),
            continuous_feature('task_ready_time'),
            continuous_feature('task_due_time'),
            continuous_feature('task_service_time'),
            continuous_feature('distance_matrix')]

variables = [task_demand_now('task_demand_now', feature='task_demand'),
             task_demand_now('task_demand_this', feature='task_demand', only_this=True),
             feature_variable('task_weight'),
             feature_variable('task_due_time'),
             feature_variable('task_ready_time'),
             feature_variable('task_service_time'),
             worker_variable('worker_weight_limit'),
             worker_variable('worker_due_time'),
             worker_variable('worker_basic_cost'),
             worker_variable('worker_distance_cost'),
             worker_used_resource('worker_used_weight', task_require='task_weight'),
             worker_used_resource('worker_used_time', 'distance_matrix', 'task_service_time', 'task_ready_time',
                'worker_ready_time'),
             edge_variable('distance_last_to_this', feature='distance_matrix', last_to_this=True),
             edge_variable('distance_this_to_task', feature='distance_matrix', this_to_task=True),
             edge_variable('distance_task_to_end', feature='distance_matrix', task_to_end=True)]


class Constraint:

    def do_task(self):
        return self.task_demand_this

    def mask_task(self):
        # 已经完成的任务
        mask = self.task_demand_now <= 0
        # 车辆容量限制
        worker_weight_limit = self.worker_weight_limit - self.worker_used_weight
        mask |= self.task_demand_now * self.task_weight > worker_weight_limit[:, None]

        worker_used_time = self.worker_used_time[:, None] + self.distance_this_to_task
        mask |= worker_used_time > self.task_due_time

        worker_used_time = torch.max(worker_used_time, self.task_ready_time)
        worker_used_time += self.task_service_time
        worker_used_time += self.distance_task_to_end
        mask |= worker_used_time > self.worker_due_time[:, None]

        return mask

    def finished(self):
        return torch.all(self.task_demand_now <= 0, 1)


class Objective:

    def step_worker_start(self):
        return self.worker_basic_cost

    def step_worker_end(self):
        return self.distance_last_to_this * self.worker_distance_cost

    def step_task(self):
        return self.distance_last_to_this * self.worker_distance_cost
```

</details>

### Travelling Salesman Problem(TSP)
<details>
    <summary>TSP</summary>

```python
from greedrl.feature import *
from greedrl.variable import *
from greedrl import Problem
from greedrl import runner

features = [continuous_feature('task_location'),
            variable_feature('distance_this_to_task'),
            variable_feature('distance_task_to_end')]

variables = [task_demand_now('task_demand_now', feature='task_demand'),
             task_demand_now('task_demand_this', feature='task_demand', only_this=True),
             edge_variable('distance_last_to_this', feature='distance_matrix', last_to_this=True),
             edge_variable('distance_this_to_task', feature='distance_matrix', this_to_task=True),
             edge_variable('distance_task_to_end', feature='distance_matrix', task_to_end=True),
             edge_variable('distance_last_to_loop', feature='distance_matrix', last_to_loop=True)]


class Constraint:

    def do_task(self):
        return self.task_demand_this

    def mask_task(self):
        mask = self.task_demand_now <= 0
        return mask

    def mask_worker_end(self):
        return torch.any(self.task_demand_now > 0, 1)

    def finished(self):
        return torch.all(self.task_demand_now <= 0, 1)


class Objective:

    def step_worker_end(self):
        return self.distance_last_to_loop

    def step_task(self):
        return self.distance_last_to_this
```

</details>

### Split Delivery Vehicle Routing Problem(SDVRP)
<details>
    <summary>SDVRP</summary>

```python
from greedrl.feature import *
from greedrl.variable import *
from greedrl import Problem
from greedrl import runner

features = [continuous_feature('task_demand'),
            continuous_feature('worker_weight_limit'),
            continuous_feature('distance_matrix'),
            variable_feature('distance_this_to_task'),
            variable_feature('distance_task_to_end')]

variables = [task_demand_now('task_demand'),
             task_demand_now('task_demand_this', feature='task_demand', only_this=True),
             feature_variable('task_weight'),
             task_variable('task_weight_this', feature='task_weight'),
             worker_variable('worker_weight_limit'),
             worker_used_resource('worker_used_weight', task_require='task_weight'),
             edge_variable('distance_last_to_this', feature='distance_matrix', last_to_this=True)]


class Constraint:

    def do_task(self):
        worker_weight_limit = self.worker_weight_limit - self.worker_used_weight
        return torch.min(self.task_demand_this, worker_weight_limit // self.task_weight_this)

    def mask_task(self):
        mask = self.task_demand <= 0
        worker_weight_limit = self.worker_weight_limit - self.worker_used_weight
        mask |= self.task_weight > worker_weight_limit[:, None]
        return mask

    def finished(self):
        return torch.all(self.task_demand <= 0, 1)


class Objective:

    def step_worker_end(self):
        return self.distance_last_to_this

    def step_task(self):
        return self.distance_last_to_this
```

</details>

### Realistic Business Scenario
<details>
    <summary>real-time Dynamic Pickup and Delivery Problem(DPDP)</summary>

```python
from greedrl.feature import *
from greedrl.variable import *
from greedrl.function import *
from greedrl import Problem
from greedrl import runner

features = [local_category('task_order'),
            global_category('task_type', 2),
            global_category('task_new_order', 2),
            variable_feature('time_this_to_task'),
            continuous_feature('x_time_matrix'),
            continuous_feature('task_due_time_x'),
            continuous_feature('worker_task_mask')]

variables = [task_demand_now('task_demand_now', feature='task_demand'),
             task_demand_now('task_demand_this', feature='task_demand', only_this=True),
             task_variable('task_pickup_this', feature='task_pickup'),
             task_variable('task_due_time_this', feature='task_due_time'),
             feature_variable('task_order', feature='task_order'),
             feature_variable('task_type', feature='task_type'),
             feature_variable('task_new_pickup', feature='task_new_pickup'),
             feature_variable('worker_task_mask', feature='worker_task_mask'),
             worker_count_now('worker_count_now', feature='worker_count'),
             worker_variable('worker_min_old_task_this', feature='worker_min_old_task'),
             worker_variable('worker_max_new_order_this', feature='worker_max_new_order'),
             worker_variable('worker_task_mask_this', feature='worker_task_mask'),
             worker_used_resource('worker_used_old_task', task_require='task_old'),
             worker_used_resource('worker_used_new_order', task_require='task_new_pickup'),
             worker_used_resource('worker_used_time', edge_require='time_matrix'),
             edge_variable('time_this_to_task', feature='x_time_matrix', this_to_task=True)]


class Constraint:

    def do_task(self):
        return self.task_demand_this

    def mask_worker_start(self):
        mask = self.worker_count_now <= 0

        finished = self.task_demand_now <= 0
        worker_task_mask = self.worker_task_mask | finished[:, None, :]
        mask |= torch.all(worker_task_mask, 2)

        return mask

    def mask_worker_end(self):
        mask = self.worker_used_old_task < self.worker_min_old_task_this
        mask |= task_group_split(self.task_order, self.task_demand_now <= 0)
        return mask

    def mask_task(self):
        mask = self.task_demand_now <= 0

        mask |= task_group_priority(self.task_order, self.task_type, mask)

        worker_max_new_order = self.worker_max_new_order_this - self.worker_used_new_order
        mask |= self.task_new_pickup > worker_max_new_order[:, None]

        mask |= self.worker_task_mask_this

        return mask

    def finished(self):
        worker_mask = self.worker_count_now <= 0
        task_mask = self.task_demand_now <= 0
        worker_task_mask = worker_mask[:, :, None] | task_mask[:, None, :]

        worker_task_mask |= self.worker_task_mask
        batch_size = worker_task_mask.size(0)
        worker_task_mask = worker_task_mask.view(batch_size, -1)
        return worker_task_mask.all(1)


class Objective:

    def step_task(self):
        over_time = (self.worker_used_time - self.task_due_time_this).clamp(min=0)
        pickup_time = self.worker_used_time * self.task_pickup_this
        return self.worker_used_time + over_time + pickup_time

    def step_finish(self):
        return self.task_demand_now.sum(1) * 1000
```

</details>

### Order Batching Problem
<details>
    <summary>Batching</summary>

```python
from greedrl import Problem, Solver
from greedrl.feature import *
from greedrl.variable import *
from greedrl import runner


features = [local_feature('task_area'),
            local_feature('task_roadway'),
            local_feature('task_area_group'),
            sparse_local_feature('task_item_id', 'task_item_num'),
            sparse_local_feature('task_item_owner_id', 'task_item_num'),
            variable_feature('worker_task_item'),
            variable_feature('worker_used_roadway'),
            variable_feature('worker_used_area')]

variables = [task_demand_now('task_demand_now', feature='task_demand'),
             task_demand_now('task_demand_this', feature='task_demand', only_this=True),
             feature_variable('task_item_id'),
             feature_variable('task_item_num'),
             feature_variable('task_item_owner_id'),
             feature_variable('task_area'),
             feature_variable('task_area_group'),
             feature_variable('task_load'),
             feature_variable('task_group'),
             worker_variable('worker_load_limit'),
             worker_variable('worker_area_limit'),
             worker_variable('worker_area_group_limit'),
             worker_task_item('worker_task_item', item_id='task_item_id', item_num='task_item_num'),
             worker_task_item('worker_task_item_owner', item_id='task_item_owner_id', item_num='task_item_num'),
             worker_used_resource('worker_used_load', task_require='task_load'),
             worker_used_resource('worker_used_area', task_require='task_area'),
             worker_used_resource('worker_used_roadway', task_require='task_roadway'),
             worker_used_resource('worker_used_area_group', task_require='task_area_group')]


class Constraint:

    def do_task(self):
        return self.task_demand_this

    def mask_worker_end(self):
        return self.worker_used_load < self.worker_load_limit

    def mask_task(self):
        # completed tasks
        mask = self.task_demand_now <= 0
        # mask |= task_group_priority(self.task_group, self.task_out_stock_time, mask)

        NT = self.task_item_id.size(1)
        worker_task_item = self.worker_task_item[:, None, :]
        worker_task_item = worker_task_item.expand(-1, NT, -1)
        task_item_in_worker = worker_task_item.gather(2, self.task_item_id.long())
        task_item_in_worker = (task_item_in_worker > 0) & (self.task_item_num > 0)

        worker_task_item_owner = self.worker_task_item_owner[:, None, :]
        worker_task_item_owner = worker_task_item_owner.expand(-1, NT, -1)
        task_item_owner_in_worker = worker_task_item_owner.gather(2, self.task_item_owner_id.long())
        task_item_owner_in_worker = (task_item_owner_in_worker > 0) & (self.task_item_num > 0)

        # 
        mask |= torch.any(task_item_in_worker & ~task_item_owner_in_worker, 2)

        worker_load_limit = self.worker_load_limit - self.worker_used_load
        mask |= (self.task_load > worker_load_limit[:, None])

        task_area = self.task_area + self.worker_used_area[:, None, :]
        task_area_num = task_area.clamp(0, 1).sum(2, dtype=torch.int32)
        mask |= (task_area_num > self.worker_area_limit[:, None])

        tak_area_group = self.task_area_group + self.worker_used_area_group[:, None, :]
        tak_area_group_num = tak_area_group.clamp(0, 1).sum(2, dtype=torch.int32)
        mask |= (tak_area_group_num > self.worker_area_group_limit[:, None])

        return mask

    def finished(self):
        return torch.all(self.task_demand_now <= 0, 1)


class Objective:

    def step_worker_end(self):
        area_num = self.worker_used_area.clamp(0, 1).sum(1)
        roadway_num = self.worker_used_roadway.clamp(0, 1).sum(1)
        item_num = self.worker_task_item.clamp(0, 1).sum(1)
        penalty = (self.worker_load_limit - self.worker_used_load) * 10
        return area_num * 100 + roadway_num * 10 + item_num + penalty
```

</details>

# 

# 🤠GreedRL-CVRP-pretrained model


## Model description




## Intended uses & limitations

You can use these model for solving the vehicle routing problems (VRPs) with reinforcement learning (RL).

## How to use

### Requirements
This library requires Python == 3.8. [Miniconda](https://docs.conda.io/en/latest/miniconda.html#system-requirements) / [Anaconda](https://docs.anaconda.com/anaconda/install/) is our recommended Python distribution.

```aidl
pip install torch==1.12.1+cu113 torchvision==0.13.1+cu113 torchaudio==0.12.1 --extra-index-url https://download.pytorch.org/whl/cu113
```

You need to compile first and add the resulting library `greedrl_c` to the `PYTHONPATH`

```aidl
python setup.py build

export PYTHONPATH={root_path}/greedrl/build/lib.linux-x86_64-cpython-38/:$PYTHONPATH
```


### Training

We provide example of Capacitated VRP(CVRP) for training and inference.

1. Training data

We use the generated data for the training phase, the customers and depot locations are randomly generated in the unit square [0,1] X [0,1].

For the CVRP, we assume that the demand of each node is a discrete number in {1,...,9}, chosen uniformly at random.


2. Start training
```python
cd examples/cvrp

python train.py --model_filename cvrp_5000.pt --problem_size 5000
```

### Evaluation

We provide some pretrained models for different CVRP problem sizes, such as `cvrp_100`, `cvrp_1000`, `cvrp_2000` and `cvrp_5000`, that you can directly use for inference.

```python
cd examples/cvrp

python solve.py --device cuda --model_name cvrp_5000.pt --problem_size 5000
```

## Support
For commercial enquiries, please contact [us](huangxuankun.hxk@cainiao.com).

## About GreedRL
- Website: https://greedrl.github.io/