fix doc (#2137)

dygraph/docs/MODEL_ZOO_cn.md

@@ -30,36 +30,36 @@ Paddle提供基于ImageNet的骨架网络预训练模型。所有预训练模型
 
 ### Faster R-CNN
 
-请参考[Faster R-CNN](https://github.com/PaddlePaddle/PaddleDetection/tree/dygraph/configs/faster_rcnn/)
+请参考[Faster R-CNN](https://github.com/PaddlePaddle/PaddleDetection/tree/master/dygraph/configs/faster_rcnn/)
 
 ### Mask R-CNN
 
-请参考[Mask R-CNN](https://github.com/PaddlePaddle/PaddleDetection/tree/dygraph/configs/mask_rcnn/)
+请参考[Mask R-CNN](https://github.com/PaddlePaddle/PaddleDetection/tree/master/dygraph/configs/mask_rcnn/)
 
 ### Cascade R-CNN
 
-请参考[Cascade R-CNN](https://github.com/PaddlePaddle/PaddleDetection/tree/dygraph/configs/cascade_rcnn/)
+请参考[Cascade R-CNN](https://github.com/PaddlePaddle/PaddleDetection/tree/master/dygraph/configs/cascade_rcnn/)
 
 ### YOLOv3
 
-请参考[YOLOv3](https://github.com/PaddlePaddle/PaddleDetection/tree/dygraph/configs/yolov3/)
+请参考[YOLOv3](https://github.com/PaddlePaddle/PaddleDetection/tree/master/dygraph/configs/yolov3/)
 
 ### SSD
 
-请参考[SSD](https://github.com/PaddlePaddle/PaddleDetection/tree/dygraph/configs/ssd/)
+请参考[SSD](https://github.com/PaddlePaddle/PaddleDetection/tree/master/dygraph/configs/ssd/)
 
 ### FCOS
 
-请参考[FCOS](https://github.com/PaddlePaddle/PaddleDetection/tree/dygraph/configs/fcos/)
+请参考[FCOS](https://github.com/PaddlePaddle/PaddleDetection/tree/master/dygraph/configs/fcos/)
 
 ### SOLOv2
 
-请参考[SOLOv2](https://github.com/PaddlePaddle/PaddleDetection/tree/dygraph/configs/solov2/)
+请参考[SOLOv2](https://github.com/PaddlePaddle/PaddleDetection/tree/master/dygraph/configs/solov2/)
 
 ### PP-YOLO
 
-请参考[PP-YOLO](https://github.com/PaddlePaddle/PaddleDetection/tree/dygraph/configs/ppyolo/)
+请参考[PP-YOLO](https://github.com/PaddlePaddle/PaddleDetection/tree/master/dygraph/configs/ppyolo/)
 
 ### TTFNet
 
-请参考[TTFNet](https://github.com/PaddlePaddle/PaddleDetection/tree/dygraph/configs/ttfnet/)
+请参考[TTFNet](https://github.com/PaddlePaddle/PaddleDetection/tree/master/dygraph/configs/ttfnet/)

dygraph/docs/tutorials/INSTALL_cn.md

@@ -12,10 +12,10 @@
 
 **环境需求:**
 
-- paddlepaddle >= 2.0rc1
+- PaddlePaddle 每日版本
 - OS 64位操作系统
 - Python 3(3.5.1+/3.6/3.7)，64位版本
-- pip/pip3(9.0.1+)，64位版本操作系统是
+- pip/pip3(9.0.1+)，64位版本
 - CUDA >= 9.0
 - cuDNN >= 7.6
 
@@ -59,6 +59,21 @@ git clone https://gitee.com/paddlepaddle/PaddleDetection
 **安装PaddleDetection库:**
 
 ```
-cd PaddleDetection
+cd PaddleDetection/dygraph
 python setup.py install
 ```
+
+**预训练模型预测**
+
+使用预训练模型预测图像，快速体验模型预测效果：
+
+```
+# use_gpu参数设置是否使用GPU
+python tools/infer.py -c configs/ppyolo/ppyolo_r50vd_dcn_1x_coco.yml -o use_gpu=true weights=https://paddlemodels.bj.bcebos.com/object_detection/dygraph/ppyolo_r50vd_dcn_1x_coco.pdparams --infer_img=demo/000000014439.jpg
+```
+
+会在`output`文件夹下生成一个画有预测结果的同名图像。
+
+结果如下图：
+
+![](../images/000000014439.jpg)