MAN Truck & Bus
has been the system manager responsible for forward and lateral guidance functions in driver assistance systems at MAN since 2020. He and a team of five to eight developers and testers had already realised MAN CruiseAssist as early as 2016.
Lachner This assistance system helps drivers with the lateral and longitudinal guidance of the vehicle over the entire speed range via a combination of active lane departure warning system and ACC Stop & Go. The system continuously keeps the vehicle in its lane by means of active steering interventions. It also independently regulates the set speed and the preset distance from the vehicle in front. The assistant can be used on motorways and dual carriageways which are close to motorway standards.
Lachner Partially automated driving using MAN CruiseAssist relieves drivers and gives them greater safety and convenience in different driving situations. In heavy traffic, the assistant helps them to maintain adequate distance to the vehicle in front without wasting space. On long, monotonous journeys, in contrast, the assistance system takes on something like the function of a co-pilot – always paying attention and performing little steering corrections in good time. The drivers do of course still remain responsible and have to constantly monitor the system, but the relief means they stay alert longer and are a lot more relaxed after their shift.
Lachner The front camera identifies the lane markings for lane guidance. The front radar monitors the traffic ahead and detects stationary vehicles in the adjacent lane, while the side radar units detect lateral obstacles. An algorithm also uses torque sensing on the steering actuator to monitor whether drivers have their hands on the steering wheel. We were generally able to rely on existing technical components as we were developing MAN CruiseAssist. The vast majority of our work involved programming the software for the line detection camera and the control system for lane tracking.
Lachner We felt it was important not to create isolated solutions, but to develop a holistic system from which various assistance systems can be derived of with little effort, depending on customer needs. We managed to achieve this with systems like our LDW lane departure warning, LRA lane recovery assistant, TJA traffic jam assistant and MAN CruiseAssist, which consistently build on one another. Introducing the systems in stages enabled us to gain experience in forward and lateral guidance functions, which minimised our product risk.
Lachner One example is when we managed to design the automated forward and lateral guidance functions to respond in the same way as drivers would behave. Drivers tend not to drive in the middle of lanes, rather slightly to one side to leave more space on the side that other traffic will overtake. In exactly the same way in countries where traffic drives on the right, MAN CruiseAssist selects an alignment in the lane that is slightly offset to the right. On the other hand, in situations where driving offset to the right is distracting – for example when overtaking other road users or when there is a vehicle on the hard shoulder – MAN CruiseAssist recognises the situation and keeps the truck in the middle of the lane. Drivers feel particularly at ease with the flexibility of the assistant’s steering.
Lachner By further developing the camera and radar sensor systems we intend that in future the assistant will not only recognise the lane markings, but also the asphalted roadside and know exactly how much free space is available in front of the vehicle. We also want to further develop the automated reaction in cases where the driver doesn’t take the wheel despite repeated warnings.
Lachner If the system detects that a driver doesn’t have their hands on the steering wheel when MAN CruiseAssist is active, there will be a “hands off” escalation over three stages: the first stage involves the driver receiving a display in the cluster. Instead of a tone, in this stage the driver is notified of the display by a gentle steering wheel vibration. This avoids any distraction of the driver and passenger that could be caused by an acoustic signal. The displays become more prominent if the driver doesn’t react to this warning. In other words the vibration becomes stronger and a continuous chime is sounded. The system is deactivated if the driver still doesn’t assume control of the steering.
Lachner We’re a strong and highly motivated team with cross-functional expertise. We retreated into a room for long periods of intense collaboration in the early stages of development. Being screened from any disruptive factors, having lots of freedom in our development and an agile way of working enabled us to realise the project. A combination of all these aspects led to our success.