An autonomous mobile robot (AMR) with a single modular platform to mount a plurality of material handling units, comprising: a monolithic chassis ; a top plate comprising a plurality of standoffs to mount at least one material handling units; wherein the plurality of standoffs are integrated on top of the top plate , wherein the plurality of standoffs links the top plate and the monolithic chassis to provide load transfer area for the top plate such that the load is transferred from the plurality of material handling units through the plurality of standoffs to the top plate and then to the monolithic chassis , wherein the linkage of the plurality of standoffs with the top plate and the monolithic chassis avoids deflection of the top plate , and wherein the plurality of standoffs act as locating points for the top plate ; drive wheels (130A-B) coupled to a wheel mount as a single unit to form a drive wheel assembly ; a suspension unit coupled between the monolithic chassis and the drive wheel assembly , wherein the suspension unit comprises (a) spring enclosures (306A-B), (b) suspension shafts (312A-B), and (c) coil springs (308A-B) arranged symmetrically, wherein the suspension shafts (312A-B) are connected to the wheel mount , wherein the wheel mount is rigidly connected to the drive wheels (130A-B), and the spring enclosure (306A-B) are rigidly connected to the monolithic chassis , and wherein the suspension unit is supported by a plurality of linear bearings (302A-D) that allows the drive wheels (130A-B) to move up and down together as one unit in a vertical direction, and wherein the drive wheels (130 A-B) touch ground to produce a driving torque, and four swivel wheels (134A-D) being coupled at four corners of the monolithic chassis allowing the AMR to move freely on the ground; and a set of side plates (108A-B) connected to the monolithic chassis on either side of the AMR . a monolithic chassis ; a top plate comprising a plurality of standoffs to mount at least one material handling units; wherein the plurality of standoffs are integrated on top of the top plate , wherein the plurality of standoffs links the top plate and the monolithic chassis to provide load transfer area for the top plate such that the load is transferred from the plurality of material handling units through the plurality of standoffs to the top plate and then to the monolithic chassis , wherein the linkage of the plurality of standoffs with the top plate and the monolithic chassis avoids deflection of the top plate , and wherein the plurality of standoffs act as locating points for the top plate ; drive wheels (130A-B) coupled to a wheel mount as a single unit to form a drive wheel assembly ; a suspension unit coupled between the monolithic chassis and the drive wheel assembly , wherein the suspension unit comprises (a) spring enclosures (306A-B), (b) suspension shafts (312A-B), and (c) coil springs (308A-B) arranged symmetrically, wherein the suspension shafts (312A-B) are connected to the wheel mount , wherein the wheel mount is rigidly connected to the drive wheels (130A-B), and the spring enclosure (306A-B) are rigidly connected to the monolithic chassis , and wherein the suspension unit is supported by a plurality of linear bearings (302A-D) that allows the drive wheels (130A-B) to move up and down together as one unit in a vertical direction, and wherein the drive wheels (130 A-B) touch ground to produce a driving torque, and four swivel wheels (134A-D) being coupled at four corners of the monolithic chassis allowing the AMR to move freely on the ground; and a set of side plates (108A-B) connected to the monolithic chassis on either side of the AMR . <EOS>