Aerial work platform, and method for controlling an aerial work platform

Aerial work platform including:

• a chassis which is provided with ground translation members,
• a basket which is adapted for an operator to stand on,
• a lifting structure, which supports the basket and is arranged on the chassis so as to more or less lift the basket relative to the chassis,
• hydraulic actuators which act on respective parts of the lifting structure so as to displace said respective parts relative to the rest of the lifting structure or relative to the chassis,
• a hydraulic system comprising:
• a circulation circuit through which fluid flows between a reservoir and the hydraulic actuators,
• a motor pump which is electric and draws fluid from the reservoir and delivers to the circulation circuit for circulation, and
• a flow regulation sub-system for regulating fluid flow in the circulation circuit between the reservoir and the hydraulic actuators, and
• a control unit allowing to control the hydraulic system,
• wherein the hydraulic actuators are divided between a first group of one or more of the hydraulic actuators and a second group of one or more of the hydraulic actuators, the hydraulic actuator or actuators of the first group being distinct from the hydraulic actuator or actuators of the second group,
• wherein the control unit is able to:
• determine both a first target flow rate as a function of by-operator activation of the hydraulic actuator(s) of the first group and a second target flow rate as a function of by-operator activation of the hydraulic actuator(s) of the second group, and
• control the motor pump so that the motor pump delivers the fluid at a delivery flow rate which is greater than or equal to the sum of the first and second target flow rates,
• wherein the flow regulation sub-system is able, by being controlled by the control unit, to:
• send jointly toward the first and second groups a regulated proportion of fluid delivered by the motor pump, this regulated proportion presenting a controlled flow rate which is equal to the sum of the first and second target flow rates, then
• dividing said regulated proportion into two adjusted portions, which respectively present the first and second target flow rates and which are respectively sent to the first group and to the second group,
• wherein the flow regulation sub-system comprises a flow distribution device which:
• is provided with three ports, namely an inlet port, which is supplied with said regulated proportion of the fluid delivered by the motor pump, a first outlet port-(92B), which supplies fluid to the first group, and a second outlet port, which supplies fluid to the second group, and
• is able to distribute all fluid in the inlet port between the first and second outlet ports, the flow distribution device being controlled by the control unit so that the first outlet port receives the adjusted portion presenting the first target flow rate and the second outlet port receives the adjusted portion presenting the second target flow rate,
• and wherein the flow regulation sub-system further comprises a flow regulating device, which:
• is provided with three ports, namely an intake port, which receives all fluid delivered by the motor pump, a main outlet port, which sends fluid to the inlet port of the flow distribution device, and a secondary outlet port, which sends fluid directly to the reservoir, and
• is able to regulate a flow of fluid from the intake port toward the main and secondary outlet ports, the flow regulating device being controlled by the control unit so that the main outlet port receives said regulated proportion of fluid delivered by the motor pump (80) while a surplus of fluid delivered by the motor pump, which has a flow rate equal to the difference between the delivered flow rate and the controlled flow rate, is evacuated through the secondary outlet port.