In crane choosing , three parameters should be taken into consideration : payload capacity ( q ) , lifting height ( h ) and working radius ( r ) . and three parameters should meet design requirements at the same time 选择起重机的型号原则是所选起重机的三个工作参数,即起重量q ,起重高度h和工作幅度(回转半径) r均需要满足班组结构吊装要求。